This document is a research project submitted by Mateus António da Conceição Púcuta to the University of Namibia in partial fulfillment of the requirements for a Bachelor of Science degree. The project involves the design and synthesis of isatin analogues, with the goal of obtaining novel compounds with potential anti-HIV activity. The document includes a dedication, acknowledgements, list of abbreviations, list of figures/schemes/tables, and abstract summarizing the work. It also provides background information on natural products and their importance as sources of new drugs.
This dissertation describes the isolation and structural elucidation of natural products from various plant materials. Chromatographic and spectroscopic techniques were used to isolate and determine the structures of terpenes, terpenoids, and other secondary metabolites. Several hitherto unknown compounds were characterized, including (+)-axinyssene from Otostegia integrifolia, guaia-1(10),11-diene and guaia-9,11-diene from Peucedanum tauricum, four sesquiterpenoids from Chloranthus spicatus, isoligustilide from Meum athamanticum, and two diterpenes and four sesquiterpenes from Rad
ABSTRACT- This research evaluated the phytotoxic effect of the hexane (H.E), ethyl acetate (EtOAc.E) and methanolic (MeOH.E) crude extracts of the Tephrosia cinerea leaves on the seed germination of seeds using two weed species, Mimosa pudica (Malícia) and Senna obtusifolia (Mata-pasto), as test plants. The compounds were isolated using classic chromatography techniques and the structural elucidation of the compounds was performed by 1H and 13C NMR (1D and 2D) techniques. The ethyl acetate and methanolic extracts of T. cinerea were the most active, as they inhibited the germination of seeds in 92.0% and 81.0% respectively of malícia and mata-pasto, the ethyl acetate extract inhibited germination by 81.0% and the methanolic extract by 32.0%. The chemical study led to isolation of cinnamic acid and rotenone from the ethyl acetate extract, and mixture containing triacylglycerol and β-sitosterol fatty acids from the hexane extract and the disaccharide trehalose from methanolic extract.
Key-words- Invasive species, Phytotoxicity, Crude extracts, Rotenone
1) The document describes a rapid method for extracting genomic DNA from filamentous fungi that involves bead beating to disrupt fungal cell walls followed by phenol-chloroform extraction and isopropanol precipitation.
2) The method yields 60-230 μg of high quality DNA per 200 mg of fungal mass within 2.5 hours without enzymatic digestion.
3) The extracted DNA was suitable for downstream PCR applications like gene amplification and RAPD analysis, demonstrating its utility for high-throughput fungal identification.
Mathew Pucuta - Official Research Project PresentationMateus Púcuta
The document describes the design and synthesis of isatin analogues by Mateus A. da C. Púcuta for their Master's thesis. The objectives were to design isatin analogues, synthesize them, and characterize the synthesized analogues. Isatin was selected as the natural product scaffold due to its wide range of biological activities. Various isatin analogues were designed and synthesized involving steps such as N-alkylation, O-alkylation, aldol condensation, and click reactions. The analogues and intermediates were characterized by melting point, TLC, NMR, and mass spectrometry. Further testing of the analogues for inhibitory activity against HIV protease and reverse transcriptase is proposed. The objectives were partially
This document summarizes research on photovoltaic (PV) system performance in Antofagasta, Chile. It discusses the high solar radiation levels and clear skies in northern Chile, as well as the different environmental conditions compared to other parts of the world. Several PV plants using thin-film, mono-crystalline silicon, and multi-crystalline silicon technologies were analyzed. Performance ratios declined over time due to dust deposition. Levelized costs of energy were calculated considering performance and costs. Future work is planned to further study material degradation under Chile's conditions.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise causes chemical changes in the brain that may help boost feelings of calmness, happiness and focus.
Selling a home is an important financial decision for buyers. There are advantages to both new and older homes that should be considered. Buyers are primarily motivated by benefits like appreciation, tax breaks, and equity buildup. Effective selling requires strong communication skills like listening and presenting information visually. The critical path to a sale involves pre-approach, initial contact, counseling buyers, planning showings, handling objections, and closing the deal. Closing techniques focus on persuasion by addressing the buyer's needs.
- The document discusses the opportunities and challenges for foreign retail and consumer goods companies in India. While reforms under Prime Minister Modi have improved optimism, challenges remain.
- Key reforms like the nationwide Goods and Services Tax (GST) could boost the sector but are still pending approval. Foreign direct investment restrictions also limit multi-brand retailers.
- Success requires understanding varied local markets, tastes, and customs. Foreign companies must work with influential local partners who have on-the-ground knowledge to navigate the complex Indian market effectively.
This dissertation describes the isolation and structural elucidation of natural products from various plant materials. Chromatographic and spectroscopic techniques were used to isolate and determine the structures of terpenes, terpenoids, and other secondary metabolites. Several hitherto unknown compounds were characterized, including (+)-axinyssene from Otostegia integrifolia, guaia-1(10),11-diene and guaia-9,11-diene from Peucedanum tauricum, four sesquiterpenoids from Chloranthus spicatus, isoligustilide from Meum athamanticum, and two diterpenes and four sesquiterpenes from Rad
ABSTRACT- This research evaluated the phytotoxic effect of the hexane (H.E), ethyl acetate (EtOAc.E) and methanolic (MeOH.E) crude extracts of the Tephrosia cinerea leaves on the seed germination of seeds using two weed species, Mimosa pudica (Malícia) and Senna obtusifolia (Mata-pasto), as test plants. The compounds were isolated using classic chromatography techniques and the structural elucidation of the compounds was performed by 1H and 13C NMR (1D and 2D) techniques. The ethyl acetate and methanolic extracts of T. cinerea were the most active, as they inhibited the germination of seeds in 92.0% and 81.0% respectively of malícia and mata-pasto, the ethyl acetate extract inhibited germination by 81.0% and the methanolic extract by 32.0%. The chemical study led to isolation of cinnamic acid and rotenone from the ethyl acetate extract, and mixture containing triacylglycerol and β-sitosterol fatty acids from the hexane extract and the disaccharide trehalose from methanolic extract.
Key-words- Invasive species, Phytotoxicity, Crude extracts, Rotenone
1) The document describes a rapid method for extracting genomic DNA from filamentous fungi that involves bead beating to disrupt fungal cell walls followed by phenol-chloroform extraction and isopropanol precipitation.
2) The method yields 60-230 μg of high quality DNA per 200 mg of fungal mass within 2.5 hours without enzymatic digestion.
3) The extracted DNA was suitable for downstream PCR applications like gene amplification and RAPD analysis, demonstrating its utility for high-throughput fungal identification.
Mathew Pucuta - Official Research Project PresentationMateus Púcuta
The document describes the design and synthesis of isatin analogues by Mateus A. da C. Púcuta for their Master's thesis. The objectives were to design isatin analogues, synthesize them, and characterize the synthesized analogues. Isatin was selected as the natural product scaffold due to its wide range of biological activities. Various isatin analogues were designed and synthesized involving steps such as N-alkylation, O-alkylation, aldol condensation, and click reactions. The analogues and intermediates were characterized by melting point, TLC, NMR, and mass spectrometry. Further testing of the analogues for inhibitory activity against HIV protease and reverse transcriptase is proposed. The objectives were partially
This document summarizes research on photovoltaic (PV) system performance in Antofagasta, Chile. It discusses the high solar radiation levels and clear skies in northern Chile, as well as the different environmental conditions compared to other parts of the world. Several PV plants using thin-film, mono-crystalline silicon, and multi-crystalline silicon technologies were analyzed. Performance ratios declined over time due to dust deposition. Levelized costs of energy were calculated considering performance and costs. Future work is planned to further study material degradation under Chile's conditions.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise causes chemical changes in the brain that may help boost feelings of calmness, happiness and focus.
Selling a home is an important financial decision for buyers. There are advantages to both new and older homes that should be considered. Buyers are primarily motivated by benefits like appreciation, tax breaks, and equity buildup. Effective selling requires strong communication skills like listening and presenting information visually. The critical path to a sale involves pre-approach, initial contact, counseling buyers, planning showings, handling objections, and closing the deal. Closing techniques focus on persuasion by addressing the buyer's needs.
- The document discusses the opportunities and challenges for foreign retail and consumer goods companies in India. While reforms under Prime Minister Modi have improved optimism, challenges remain.
- Key reforms like the nationwide Goods and Services Tax (GST) could boost the sector but are still pending approval. Foreign direct investment restrictions also limit multi-brand retailers.
- Success requires understanding varied local markets, tastes, and customs. Foreign companies must work with influential local partners who have on-the-ground knowledge to navigate the complex Indian market effectively.
presentazione_theItalianCUT_2016_DEF_ENGKEVO Daniel
The agency provides integrated communication services including photo and video, graphic design, public relations, performance marketing, and training. They work alongside companies to develop tailored communication strategies and plans. They emphasize simplicity, sharing, and flexibility to quickly create bespoke communication projects that highlight each customer's uniqueness.
The document discusses filling out a residential purchase agreement contract in California. It explains that purchase contracts are necessary to address financing, possession, title, liens and other key aspects of a real estate transaction. The latest version of the purchase agreement form released in 2014 includes changes to provide more clarity and definite terms. Contingency clauses allow parties to be released from obligations if certain required actions are not fulfilled by a specified time. The document then provides detailed instructions for completing each section of the residential purchase agreement form, including offer details, financing terms, property disclosures, inspection contingencies, closing arrangements and other key terms.
David Kabiito received a certificate on 22-AUG-2014 for successfully participating in a training course on One-NDS 9 (Base) Directory Platform and Operation. The certificate was issued by Ann M. Kohut, Head of Academy. The training helped David learn about directory platforms and their operation.
This document summarizes a study comparing different architectures of bifacial solar modules. Indoor characterization of standard and bifacial modules was performed on a solar simulator. Outdoor testing was also conducted on small bifacial modules installed vertically east-west. Preliminary results show that modules with an up-down cell configuration performed better than up-up under bifacial illumination conditions, and gained up to 40% more power from ambient light compared to monofacial modules. Further indoor and outdoor testing is needed to better understand bifacial module performance and the potential to predict outdoor gains using indoor characterization methods.
David Kabiito received a certificate on 26-AUG-2014 for successfully participating in a Flexi Multiradio BTS TD-LTE Installation RL35TD training course. The certificate was issued by Ann M. Kohut, Head of Academy.
Eduardo Morales estudia Ingeniería Eléctrica. El documento cubre conceptos clave como circuitos eléctricos, teoremas de superposición, teoremas de Thévenin y Norton, y leyes de Kirchhoff. También explica formas de ondas, fuentes independientes y dependientes, y cómo calcular tensiones y corrientes en un circuito.
This document provides a biography and resume for Dr. Rahul A. Hajare, a researcher in biologics development and protein chemistry. It summarizes his educational background, areas of research interest, research experience, awards, academic appointments, industry experience, research projects, publications, and memberships. He has a Ph.D. from Vinayaka Mission University and positions include Associate Professor at Rajgad Dnyanpeeth's College of Pharmacy and research at the National AIDS Research Institute. His research focuses on biologics development, protein chemistry, molecular biology, and drug discovery.
This document provides a biography and resume for Dr. Rahul A. Hajare, a researcher in biologics development and protein chemistry. It summarizes his educational background, areas of research interest, research experience, awards, publications, projects, and academic appointments. Some key details include that he received a Ph.D. in 2012 from Vinayaka Mission University and has over 52 publications. His research focuses on areas like biologics development, protein chemistry, molecular biology, and drug discovery. He has worked on projects related to HIV inhibition and anticancer activity.
This document provides a detailed curriculum vitae for Muhammad Taha. It includes his personal and contact information, academic background and qualifications, research interests, publications, conference attendance, teaching experience, and supervision of students. Taha has a PhD in organic chemistry from the University of Karachi and is currently a Senior Lecturer. He has over 70 publications and an h-index of 12. His research focuses on the synthesis of bioactive compounds and developing new methodologies in synthetic organic chemistry.
This document provides a detailed bio for Dr. Rahul Anandrao Hajare, including his educational background, work experience, skills, publications, and research interests. Some key points:
- Dr. Hajare has over 10 years of experience in pharmaceutical chemistry, medicinal chemistry, and quality assurance.
- His research focuses on drug discovery, molecular docking, and computational drug repositioning for viral diseases.
- He has worked in various roles including as an ICMR postdoc, associate professor, and officer in an R&D department.
- Dr. Hajare has authored over 25 publications in peer-reviewed journals and has received awards including an ICMR post
Synthesis, spectral characterization and bioactivity studies of some S-substi...Jing Zang
A new series of 5-(4-Chlorophenyl)-1,3,4-Oxadiazol-2-thiol derivatives was prepared from 4-chlorobenzoic acid (1) by converting it successively into corresponding ester (2), carbohydrazide (3) and 5-(4-Chlorophenyl)-1,3,4-Oxadiazol-2-thiol (4). Finally the target compounds, 6a-l, were synthesized by stirring 4 with different electrophiles, 5a-l, in DMF using NaH as weak base and activator. The proposed structures of newly synthesized compounds were confirmed by spectroscopic techniques such as 1H-NMR, 13C-NMR, HR-MS and EI-MS. All synthesized compounds were evaluated for their anti-bacterial, antifungal, cytotoxicity and enzyme inhibition activities. The compounds, 6e and 6g exhibited significant inhibition activity against acetyl cholinesterase enzyme (AChE) and 6j moderate activity against butyryl cholinesterase enzyme (BChE). The molecule, 4 exhibited good MIC (minimum inhibitory concentration) value against all the bacterial and fungal strains taken into account.
The document discusses various nitrogen substitution and addition reactions including the Mannich reaction where nucleophilic nitrogen adds to saturated or unsaturated carbons. It specifically mentions the reaction of primary amines with aldehydes and ketones to form imines and the formation of amino acids through reactions like the Hell-Volhard Zelensky reaction, Gabriel procedure, nitrosation, and Strecker method.
This document discusses ester enolates and the Claisen condensation reaction. The Claisen condensation involves the deprotonation of a 3-oxoalkanoate to form an ester enolate, which then undergoes nucleophilic addition and elimination to form a β-ketoester product. The acidic hydrogens of β-ketoesters make them readily enolizable and allow the reaction to be driven to completion. Ester enolates can undergo reactions like alkylation, Michael addition, and the Robinson annulation. Methods for synthesizing α-hydroxycarbonyls involve the use of masked alkanoyl anions like 1,3-dithiane derivatives or a catalytic
The document summarizes the synthesis and characterization of a binuclear Schiff base ligand and its metal complexes with Cu(II), Ni(II), and VO(IV). The ligand was synthesized by reacting 5-bromo-3-fluorosalicylaldehyde and benzidine. The complexes were prepared by reacting the ligand with metal salts. The ligand and complexes were characterized using elemental analysis, IR, NMR, UV-Vis, magnetic susceptibility, and thermal analysis. The ligand behaves as a tetradentate ligand, coordinating through the azomethine nitrogen and deprotonated phenolic oxygen atoms. The complexes exhibit square planar and square pyramidal geometries. Antimicrobial tests found the compounds
Synthesis and characterization of mixed ligand complexes of some metals with ...Taghreed Al-Noor
This document summarizes the synthesis and characterization of mixed ligand metal complexes containing nicotinamide and L-phenylalanine. The complexes were synthesized and analyzed using various techniques such as melting point, solubility, molar conductivity, UV-Vis and FT-IR spectroscopy. The complexes had the general formula [M(NA)2(phe)]Cl, where M is a divalent metal ion such as Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) or Hg(II). The study showed that L-phenylalanine acted as a bidentate ligand through its carboxylate and amine groups, while nicotinamide coordinated as
This document is a synopsis submitted for the degree of Doctor of Philosophy in Physics at Annamalai University. It summarizes experimental and theoretical vibrational spectroscopic investigations on several organic compounds, including Schiff bases, benzenesulfonamides, amino acids, and biphenyl derivatives. Quantum chemical computations using methods like HF and DFT were used to interpret vibrational spectra from techniques like IR, Raman, and FT-Raman spectroscopy. The synopsis reviews related literature and describes the instrumentation and methodology used in the experimental and computational investigations.
This document summarizes the synthesis and characterization of new Schiff base ligands and their metal complexes. It describes the synthesis of five Schiff base ligands derived from substituted benzaldehydes and anilines using the reflux method. Copper and nickel complexes were formed from two of the ligands. The ligands and complexes were characterized using infrared spectroscopy, which showed shifts in the C=N and C-O peaks upon complexation. The research aims to synthesize new Schiff bases and their Cu2+ and Ni2+ complexes and characterize them using IR spectroscopy to determine the coordination sites.
This master's thesis investigates novel approaches to linear epitope mapping of tau protein and characterization of its interactions with anti-tau antibodies. The thesis aims to develop methods for mapping the binding sites of identified anti-tau antibodies on tau protein. Two approaches are used - Approach A involves in-solution enzymatic digestion of tau protein followed by SDS-PAGE and SEC-MALS. Approach B involves immobilizing antibodies and incubating with tau protein fragments obtained by in-solution digestion for epitope mapping. The thesis seeks to characterize antibody-tau interactions to provide insights into potential immunotherapy targets for Alzheimer's disease.
- Wajid Shah submitted a thesis titled "Cardiovascular and Chronic Respiratory Diseases Prediction System" in partial fulfillment of a Master of Science degree in computer science at Capital University of Science and Technology, Islamabad.
- The thesis proposed a system to predict symptoms of cardiovascular diseases and chronic respiratory diseases using patient vital sign data, which could help diagnose diseases earlier and start treatment.
- Vital sign data from the University of Queensland dataset was used, containing monitoring data from 32 surgical situations. Regression and classification models were developed and evaluated to predict medical situations based on vital signs.
Optimisation of X-Ray CT within SPECTCT StudiesLayal Jambi
This document discusses optimizing the X-ray CT dose in SPECT/CT studies. It begins by examining the correlation between patient body mass index (BMI) and abdominal thickness measured on CT images from SPECT/CT studies. Data from 18 patients was analyzed to determine if the anthropomorphic phantom used in the study reasonably approximated larger patients. The document then outlines a study using the phantom to acquire SPECT and CT images under various protocols to evaluate the relationship between CT dose and image noise and accuracy of attenuation correction. A nuclear medicine radiologist will then qualitatively analyze the images to determine the best protocol that maintains image quality while optimizing dose. The goal is to develop a low-dose CT protocol for use in SPECT
This syllabus of Medical Parasitology and Entomology aims to equip students with the understanding of medically important parasites. This includes their general characteristics, life cycle, and laboratory diagnosis. The students will also learn different diagnostic procedures including stool examination, blood examination, and specialized diagnostic techniques for various parasites. Practical experiments are an integral part of this syllabus, enhancing the students' understanding and skills.
Created by: Mr. Attuluri Vamsi Kumar, Assistant Professor, Department of MLT, UIAHS, Chandigarh University, Mohali, Punjab. For more details website: https://www.mltmaster.com
presentazione_theItalianCUT_2016_DEF_ENGKEVO Daniel
The agency provides integrated communication services including photo and video, graphic design, public relations, performance marketing, and training. They work alongside companies to develop tailored communication strategies and plans. They emphasize simplicity, sharing, and flexibility to quickly create bespoke communication projects that highlight each customer's uniqueness.
The document discusses filling out a residential purchase agreement contract in California. It explains that purchase contracts are necessary to address financing, possession, title, liens and other key aspects of a real estate transaction. The latest version of the purchase agreement form released in 2014 includes changes to provide more clarity and definite terms. Contingency clauses allow parties to be released from obligations if certain required actions are not fulfilled by a specified time. The document then provides detailed instructions for completing each section of the residential purchase agreement form, including offer details, financing terms, property disclosures, inspection contingencies, closing arrangements and other key terms.
David Kabiito received a certificate on 22-AUG-2014 for successfully participating in a training course on One-NDS 9 (Base) Directory Platform and Operation. The certificate was issued by Ann M. Kohut, Head of Academy. The training helped David learn about directory platforms and their operation.
This document summarizes a study comparing different architectures of bifacial solar modules. Indoor characterization of standard and bifacial modules was performed on a solar simulator. Outdoor testing was also conducted on small bifacial modules installed vertically east-west. Preliminary results show that modules with an up-down cell configuration performed better than up-up under bifacial illumination conditions, and gained up to 40% more power from ambient light compared to monofacial modules. Further indoor and outdoor testing is needed to better understand bifacial module performance and the potential to predict outdoor gains using indoor characterization methods.
David Kabiito received a certificate on 26-AUG-2014 for successfully participating in a Flexi Multiradio BTS TD-LTE Installation RL35TD training course. The certificate was issued by Ann M. Kohut, Head of Academy.
Eduardo Morales estudia Ingeniería Eléctrica. El documento cubre conceptos clave como circuitos eléctricos, teoremas de superposición, teoremas de Thévenin y Norton, y leyes de Kirchhoff. También explica formas de ondas, fuentes independientes y dependientes, y cómo calcular tensiones y corrientes en un circuito.
This document provides a biography and resume for Dr. Rahul A. Hajare, a researcher in biologics development and protein chemistry. It summarizes his educational background, areas of research interest, research experience, awards, academic appointments, industry experience, research projects, publications, and memberships. He has a Ph.D. from Vinayaka Mission University and positions include Associate Professor at Rajgad Dnyanpeeth's College of Pharmacy and research at the National AIDS Research Institute. His research focuses on biologics development, protein chemistry, molecular biology, and drug discovery.
This document provides a biography and resume for Dr. Rahul A. Hajare, a researcher in biologics development and protein chemistry. It summarizes his educational background, areas of research interest, research experience, awards, publications, projects, and academic appointments. Some key details include that he received a Ph.D. in 2012 from Vinayaka Mission University and has over 52 publications. His research focuses on areas like biologics development, protein chemistry, molecular biology, and drug discovery. He has worked on projects related to HIV inhibition and anticancer activity.
This document provides a detailed curriculum vitae for Muhammad Taha. It includes his personal and contact information, academic background and qualifications, research interests, publications, conference attendance, teaching experience, and supervision of students. Taha has a PhD in organic chemistry from the University of Karachi and is currently a Senior Lecturer. He has over 70 publications and an h-index of 12. His research focuses on the synthesis of bioactive compounds and developing new methodologies in synthetic organic chemistry.
This document provides a detailed bio for Dr. Rahul Anandrao Hajare, including his educational background, work experience, skills, publications, and research interests. Some key points:
- Dr. Hajare has over 10 years of experience in pharmaceutical chemistry, medicinal chemistry, and quality assurance.
- His research focuses on drug discovery, molecular docking, and computational drug repositioning for viral diseases.
- He has worked in various roles including as an ICMR postdoc, associate professor, and officer in an R&D department.
- Dr. Hajare has authored over 25 publications in peer-reviewed journals and has received awards including an ICMR post
Synthesis, spectral characterization and bioactivity studies of some S-substi...Jing Zang
A new series of 5-(4-Chlorophenyl)-1,3,4-Oxadiazol-2-thiol derivatives was prepared from 4-chlorobenzoic acid (1) by converting it successively into corresponding ester (2), carbohydrazide (3) and 5-(4-Chlorophenyl)-1,3,4-Oxadiazol-2-thiol (4). Finally the target compounds, 6a-l, were synthesized by stirring 4 with different electrophiles, 5a-l, in DMF using NaH as weak base and activator. The proposed structures of newly synthesized compounds were confirmed by spectroscopic techniques such as 1H-NMR, 13C-NMR, HR-MS and EI-MS. All synthesized compounds were evaluated for their anti-bacterial, antifungal, cytotoxicity and enzyme inhibition activities. The compounds, 6e and 6g exhibited significant inhibition activity against acetyl cholinesterase enzyme (AChE) and 6j moderate activity against butyryl cholinesterase enzyme (BChE). The molecule, 4 exhibited good MIC (minimum inhibitory concentration) value against all the bacterial and fungal strains taken into account.
The document discusses various nitrogen substitution and addition reactions including the Mannich reaction where nucleophilic nitrogen adds to saturated or unsaturated carbons. It specifically mentions the reaction of primary amines with aldehydes and ketones to form imines and the formation of amino acids through reactions like the Hell-Volhard Zelensky reaction, Gabriel procedure, nitrosation, and Strecker method.
This document discusses ester enolates and the Claisen condensation reaction. The Claisen condensation involves the deprotonation of a 3-oxoalkanoate to form an ester enolate, which then undergoes nucleophilic addition and elimination to form a β-ketoester product. The acidic hydrogens of β-ketoesters make them readily enolizable and allow the reaction to be driven to completion. Ester enolates can undergo reactions like alkylation, Michael addition, and the Robinson annulation. Methods for synthesizing α-hydroxycarbonyls involve the use of masked alkanoyl anions like 1,3-dithiane derivatives or a catalytic
The document summarizes the synthesis and characterization of a binuclear Schiff base ligand and its metal complexes with Cu(II), Ni(II), and VO(IV). The ligand was synthesized by reacting 5-bromo-3-fluorosalicylaldehyde and benzidine. The complexes were prepared by reacting the ligand with metal salts. The ligand and complexes were characterized using elemental analysis, IR, NMR, UV-Vis, magnetic susceptibility, and thermal analysis. The ligand behaves as a tetradentate ligand, coordinating through the azomethine nitrogen and deprotonated phenolic oxygen atoms. The complexes exhibit square planar and square pyramidal geometries. Antimicrobial tests found the compounds
Synthesis and characterization of mixed ligand complexes of some metals with ...Taghreed Al-Noor
This document summarizes the synthesis and characterization of mixed ligand metal complexes containing nicotinamide and L-phenylalanine. The complexes were synthesized and analyzed using various techniques such as melting point, solubility, molar conductivity, UV-Vis and FT-IR spectroscopy. The complexes had the general formula [M(NA)2(phe)]Cl, where M is a divalent metal ion such as Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) or Hg(II). The study showed that L-phenylalanine acted as a bidentate ligand through its carboxylate and amine groups, while nicotinamide coordinated as
This document is a synopsis submitted for the degree of Doctor of Philosophy in Physics at Annamalai University. It summarizes experimental and theoretical vibrational spectroscopic investigations on several organic compounds, including Schiff bases, benzenesulfonamides, amino acids, and biphenyl derivatives. Quantum chemical computations using methods like HF and DFT were used to interpret vibrational spectra from techniques like IR, Raman, and FT-Raman spectroscopy. The synopsis reviews related literature and describes the instrumentation and methodology used in the experimental and computational investigations.
This document summarizes the synthesis and characterization of new Schiff base ligands and their metal complexes. It describes the synthesis of five Schiff base ligands derived from substituted benzaldehydes and anilines using the reflux method. Copper and nickel complexes were formed from two of the ligands. The ligands and complexes were characterized using infrared spectroscopy, which showed shifts in the C=N and C-O peaks upon complexation. The research aims to synthesize new Schiff bases and their Cu2+ and Ni2+ complexes and characterize them using IR spectroscopy to determine the coordination sites.
This master's thesis investigates novel approaches to linear epitope mapping of tau protein and characterization of its interactions with anti-tau antibodies. The thesis aims to develop methods for mapping the binding sites of identified anti-tau antibodies on tau protein. Two approaches are used - Approach A involves in-solution enzymatic digestion of tau protein followed by SDS-PAGE and SEC-MALS. Approach B involves immobilizing antibodies and incubating with tau protein fragments obtained by in-solution digestion for epitope mapping. The thesis seeks to characterize antibody-tau interactions to provide insights into potential immunotherapy targets for Alzheimer's disease.
- Wajid Shah submitted a thesis titled "Cardiovascular and Chronic Respiratory Diseases Prediction System" in partial fulfillment of a Master of Science degree in computer science at Capital University of Science and Technology, Islamabad.
- The thesis proposed a system to predict symptoms of cardiovascular diseases and chronic respiratory diseases using patient vital sign data, which could help diagnose diseases earlier and start treatment.
- Vital sign data from the University of Queensland dataset was used, containing monitoring data from 32 surgical situations. Regression and classification models were developed and evaluated to predict medical situations based on vital signs.
Optimisation of X-Ray CT within SPECTCT StudiesLayal Jambi
This document discusses optimizing the X-ray CT dose in SPECT/CT studies. It begins by examining the correlation between patient body mass index (BMI) and abdominal thickness measured on CT images from SPECT/CT studies. Data from 18 patients was analyzed to determine if the anthropomorphic phantom used in the study reasonably approximated larger patients. The document then outlines a study using the phantom to acquire SPECT and CT images under various protocols to evaluate the relationship between CT dose and image noise and accuracy of attenuation correction. A nuclear medicine radiologist will then qualitatively analyze the images to determine the best protocol that maintains image quality while optimizing dose. The goal is to develop a low-dose CT protocol for use in SPECT
This syllabus of Medical Parasitology and Entomology aims to equip students with the understanding of medically important parasites. This includes their general characteristics, life cycle, and laboratory diagnosis. The students will also learn different diagnostic procedures including stool examination, blood examination, and specialized diagnostic techniques for various parasites. Practical experiments are an integral part of this syllabus, enhancing the students' understanding and skills.
Created by: Mr. Attuluri Vamsi Kumar, Assistant Professor, Department of MLT, UIAHS, Chandigarh University, Mohali, Punjab. For more details website: https://www.mltmaster.com
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Isolation and Identification of Tannase producing bacteria from environmental...Sunehera Sarwat
The document describes a student's project on isolating and identifying tannase-producing bacteria from soil samples. Eleven new bacterial strains were isolated, nine of which belonged to the genus Staphylococcus. Biochemical and morphological tests were used to identify the isolates. Bioinformatics analysis found that the tannase enzyme is widely distributed in both Gram-positive and Gram-negative bacteria, with the highest number found in the phylum Firmicutes. The project aims to further understand the evolution and distribution of the tannase gene in the bacterial kingdom.
A REPORT OF THE STUDENTS INDUSTRIAL WORK EXPERIENCE SCHEME(SIWES)Valerie Felton
The document provides a report on a student's 3-month industrial training at the Benue State University Teaching Hospital (BSUTH) chemical pathology department from April to June 2016. It includes an overview of BSUTH, describing its location, leadership, departments, vision, mission and organizational structure. It also outlines the student's involvement in the phlebotomy, separation, and main laboratory units. The student gained experience in blood collection techniques, urinalysis, pregnancy testing, and quantitative analysis of various analytes using spectrophotometry. Challenges encountered and recommendations are also discussed.
This document discusses Listeria monocytogenes, a foodborne pathogen that causes the disease listeriosis. It has a high mortality rate and contaminates foods like dairy, meats, and vegetables. Current detection methods take 3-4 days, so rapid detection techniques are needed. The aim of this project is to develop a biosensor that can readily detect Listeria monocytogenes using electrochemical techniques like cyclic voltammetry and electrochemical impedance spectroscopy. The biosensor will be fabricated using microfabrication techniques and functionalized with antibodies to detect the pathogen.
The use of agrochemicals has increased considerably in recent years, and consequently, there has been increased exposure of ecosystems and human populations to these highly toxic compounds. The study and development of methodologies to detect these substances with greater sensitivity has become extremely relevant. This article describes, for the first time, the use of atomic force spectroscopy (AFS) in the detection of enzyme-inhibiting herbicides. A nanobiosensor based on an atomic force microscopy (AFM) tip functionalised with the acetolactate synthase (ALS) enzyme was developed and characterised. The herbicide metsulfuron-methyl, an ALS inhibitor, was successfully detected through the acquisition of force curves using this biosensor. The adhesion force values were considerably higher when the biosensor was used. An increase of ~250% was achieved relative to the adhesion force using an unfunctionalised AFM tip. This considerable increase was the result of a specific interaction between the enzyme and the herbicide, which was primarily responsible for the efficiency of the nanobiosensor. These results indicate that this methodology is promising for the detection of herbicides, pesticides, and other environmental contaminants.
Linezolid versus vancomycin MIC assay for the treatment of infections caused ...AditiSurjeet07
This study compared the efficacy and safety of linezolid versus vancomycin for the treatment of MRSA infections in Japanese patients. One hundred patients received linezolid and 51 received vancomycin. At the end of therapy, clinical success rates were higher for linezolid than vancomycin (63% vs 50%), and microbiological eradication rates were also higher for linezolid (79% vs 30%). Adverse events like anemia and thrombocytopenia were more common with linezolid. The authors concluded that linezolid was as effective as vancomycin for treating MRSA infections and may be more effective at achieving microbiological eradication, though it had more hematological
Project report submitted to the compatibleVelentina Das
This document is a project report submitted by Velentina Das to fulfill the requirements for a Master of Science degree in Environmental Science at Tezpur University. The report studies the effect of low moisture stress on two pulse crops: black gram and green gram. It analyzes various morpho-physiological parameters and yield responses in the two crops under conditions of low moisture stress and recovery from such stress. The objectives are to examine the impact of low moisture stress on important plant parameters and yields, and to determine how the parameters change during recovery from stress.
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This document discusses using electrospray deposition to more efficiently process the cancer drug docetaxel into monodisperse nanoparticles. A binary solvent system is investigated to determine its effects on solvent evaporation and drug diffusion into particles. Material properties of the electrospray nozzle and operating conditions like temperature and solution components are explored to produce spherical 100-200nm docetaxel particles. The goal is to establish ideal electrospray deposition parameters for efficient drug processing and delivery.
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Fungal aerosole characterization and immuno detection of fungal fragmentssaberhussain9
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This document summarizes the key steps in measuring adsorption properties using a custom-built calorimeter. It describes the design criteria for the calorimeter, the theory behind ideal and practical calorimeters, and the components and operation of the instrument. It also outlines the procedures for calibrating the thermopile, accounting for heat of compression effects, calibrating the residual gas analyzer, verifying adsorption equilibrium, and determining differential heats from finite doses. The document provides an example calculation and concludes that the calorimeter can accurately measure mixture adsorption properties.
Running head Summary of research articles Summary of research.docxagnesdcarey33086
Running head: Summary of research articles
Summary of research articles 3
Summary of Qualitative and Quantitative Research Studies
Introduction
Research articles use a standard format to provide information about a research study. Readers summarize research articles in order to take notes to remember about the article, or to include the article in their research papers. However, this paper presents a summary whose reason is to enable the reader provide a critique of two research articles.
Summary of the quantitative research article
The research article “Leaves Extract from Canarium odontophyllum Miq. (Dabai) Exhibits Cytotoxic Activity against Human Colorectal Cancer Cell HCT 116”, was written by Basri, Shabry, and Meng in their quest to determine the effectiveness of leaves extracts from Dabai plant in suppressing colorectal cancers.
Research question and objective statement
The aim of the research study was assess the cytotoxic effect of water, acetone and methanol extracts from the C. odontophyllum leaves against the HCT 116 colorectal carcinoma human cells using an assay of MTT.
Hypotheses tested
Leaves extracts from C. Odontophyllum belonging to the Burseraceae species family, have greater potential of acting as an anticancer agent to alleviate colorectal cancers.
Research methods used
The researcher used experimental method collect data on the cytotoxic effect of leaves extracts from C. odontophyllum on human HCT 116 colorectal carcinoma cells. Materials used were Leaves of C. odontophyllum, acetone, methanol, distilled water, Wagner’s reagent, 1M NaOH, 0.6M HCl, and H2SO4.
Procedure
Freshly imported C. odontophyllum leaves were cut into smaller pieces and dried in an oven at 45o for 24 hours. Dried leaves with constant masses were then grinded into powder using an electrical blender and then frozen at -24o to prevent contamination. Acetone, distilled water and methanol were used to extract the dried powder. 89.69 g of powdered extract were soaked in 450 ml of acetone and mixed using magnetic stirrer at room temperature for 24 hours. The mixture was filtered twice to obtain filtrates that were mixed and then filtered further using Whatman paper No. 43. The resulting crude extract was then dried in fume hood to obtain the acetone extract. Crude methanol was also obtained using the procedure. All the extracts obtained were then stored at 40 C for at later stages.
Screening C. odontophyllum leaves for phytochemicals compound
Three qualitative chemical tests were then used to identify active components in the extracts of concentrated acetone, aqueous and methanol solutions. The alkaloid identification test involved dissolving 5 mg of each extract in distilled water before adding 3 drops of Wagner’s reagent. The solution turns to a blue-black precipitate, which reveals a positive test. Tannin identification test involved ad.
Similar to Mateus Pucuta Research Project Report - FINAL VERSION (20)
Running head Summary of research articles Summary of research.docx
Mateus Pucuta Research Project Report - FINAL VERSION
1. Design and synthesis of isatin analogues
By
Student Surname and Name Student number
Cellphone number and
email
Púcuta Mateus António da
Conceição
200968513 0813908792
mpucuta88@gmail.com
Department: Chemistry and Biochemistry
Supervisor: Dr. R. Hans
Submitted in partial fulfillment of the requirements for the degree
Bachelor of Science (honors)
in the
FACULTY OF SCIENCE
at the
UNIVERSITY OF NAMIBIA
Subject:
Research Project (CHM3810)
Date of submission:
03rd December 2014
2. FACULTY OF SCIENCE
DEPARTMENT OF CHEMISTRY AND BIOCHEMISTRY
Declaration Regarding Plagiarism
I (full names & surname): Mateus António da Conceição Púcuta
Student number: 200968513
Declare the following:
1. I understand what plagiarism entails and am aware of the University’s policy in this
regard.
2. I declare that this assignment is my own, original work. Where someone else’s work
was used (whether from a printed source, the Internet or any other source) due
acknowledgement was given and reference was made according to departmental
requirements.
3. I did not copy and paste any information directly from an electronic source (e.g. a
web page, electronic journal article or CD ROM) into this document.
4. I did not make use of another student’s previous work and submitted it as my own.
5. I did not allow and will not allow anyone to copy my work with the intention of
presenting it as his/her own work.
Signature Date
3. ii
DEDICATION
A dedication to my loving parents Maria and Jacinto Púcuta and my siblings: Fuca, Perpétua,
José, Jacinto, Pascoalina, Teresa, Isabel and João for their inspiring strength, encouragement,
support, guidance and prayers.
A special feeling of gratitude to my fiancée Tecla Tembo for the encouragement and support
throughout the process.
4. iii
ACKNOWLEDGEMENTS
I am profoundly grateful to my Lord and my God for the unconditional love, grace, guidance
and mercy He has bestowed upon me during the course of this project.
I would like to thank my supervisor Dr. Renate Hazel Hans for her guidance, support, patience
and encouragement throughout the project. A great debt of gratitude is owed to my family for
their loving support and for their belief in me. Also acknowledged is the valuable
contribution of Mr. P. Shanika for helping out in the supply of resources needed during the
project. My thanks to Mr. N. Gariseb, the project coordinator, for his efforts and his availability
for progress of this project.
I would also like to thank the Faculty of Science in the University of Namibia, and in
particularly the Chemistry and Biochemistry Department for allowing me to complete my
undergraduate studies here, I do not take the knowledge for granted. My special thanks to Prof.
Koch, University of Stellenbosch, Faculty of Science, and Chemistry Department for the NMR
analysis on all the synthesized intermediates.
Finally and with deep appreciation, I would like to thank my lab partners: Cesar Lubongo,
Iyaloo Amadhila, Viktor Ambondo and Eradius Mwaetako for their help and guidance during
the lab works.
My sincerest apologies to all persons whose contribution I might have overlooked or
dealt with inadequately.
5. iv
LIST OF ABBREVIATIONS
AlCl3 Aluminium chloride
CH2Cl2 : H2O Dichloromethane : Water
DCM Dichloromethane
DMF Dimethylformamide
eq equivalence
EtOAc Ethyl acetate
HIV/AIDS Human Immunodeficiency Virus/Acquired Immune Deficiency
Syndrome
K2CO3 Potassium carbonate
MeOH Methanol
mol moles
mol % mole percentage
mmol millimoles
NaOH Sodium Hydroxide
Na2SO4 Sodium Sulphate
NMR Nuclear Magnetic Resonance
Rf Retardation factor
SARS Severe Acute Respiratory Syndrome
TB Tuberculosis
TLC Thin Layer Chromatography
w/v weight per volume
6. v
LIST OF FIGURES, SCHEMES AND TABLE
Figure 1: Examples of medicines from plants .......................................................................................1
Figure 2: Structure of isatin ...................................................................................................................2
Figure 3: Sources of natural products ....................................................................................................4
Figure 4: Example of a natural product isolated from microorganism.................................................4
Figure 5: Examples of natural products from marine organisms...........................................................5
Figure 6: Examples of natural products from animal sources................................................................5
Figure 7: Example of a natural product from plants source...................................................................6
Figure 8: Isatinyl thiosemicarbazone derivative....................................................................................7
Figure 9: Lamivudine and its derivative ................................................................................................7
Figure 10: Target molecule....................................................................................................................8
Figure 11: 1
H NMR spectrum showing all signals of compound 21 in CDCl3 at 500 MHz................19
Figure 12: 1
H NMR spectrum showing all signals of compound 21 in CDCl3 at 500 MHz – expansion
of region 7.06 - 7.60...........................................................................................................................20
Figure 13: 13
C NMR spectrum of compound 21..................................................................................21
Scheme 1: Retrosynthesis of target molecule.......................................................................................10
Scheme 2: Mechanism for Aldol condensation....................................................................................13
Scheme 3: Proposed mechanism for the Cu(I)-catalyzed azide-acetylene cycloaddition ...................14
Table 1: Table of synthesized intermediates and target molecules......................................................15
7. vi
ABSTRACT
HIV/AIDS and TB are infectious diseases responsible for a quarter of all deaths worldwide and
Africa has the highest burden of these diseases. The etiological agents of these infectious
diseases develop resistance against most of the clinically used drugs which increases the need
for more potent drugs with potentially new modes of action.
Natural products are the most consistent, valuable source of drug leads because they provide
greater structural diversity than compounds derived through combinatorial synthesis. This
offers an opportunity for finding novel low molecular weight lead structures that are potentially
active against a wide range of assay targets. Isatin, the natural product scaffold chosen for this
study, and its derivatives have been reported to display antiviral activities against the Severe
Acute Respiratory Syndrome (SARS) virus. There also exist reports on the inhibitory activity
of isatin-β-thiosemicarbazones and other isatin derivatives against HIV replication. The
objective of this study is therefore to synthetically modify the isatin scaffold in order to obtain
novel isatin analogues with potential anti-HIV activity.
Synthesis of the designed isatin analogues was done using reported procedures. For the
characterization of the synthesized analogues physical data, such as melting point and
retardation factor, as well as spectral data – Infrared, 1
H NMR and 13
C NMR - were obtained.
An acetylenic isatin, O-alkylated benzaldehydes and azido chalcones were synthesized and the
yields of 37, 27, 53, 33, 95, 89, 61, 76, 76, and 96 % respectively were obtained. Three triazole
derivatives (target molecules) were synthesized and obtained they yield of 51%, 48% and 38%,
respectively. Spectral and melting point data confirmed the proposed structures for known
intermediates. After structure confirmation these novel analogues will be submitted for testing
of inhibitory activity against HIV protease and reverse transcriptase at the Chemistry and
Biochemistry Department (UNAM)).
8. vii
TABLE OF CONTENTS
Dedication..................................................................................................................................ii
Acknowledgements.................................................................................................................. iii
List of abbreviations .................................................................................................................iv
List of figures, schemes and table..............................................................................................v
Abstract.....................................................................................................................................vi
Table of contents......................................................................................................................vii
1. Introduction ........................................................................................................................1
2. Motivation of study ............................................................................................................3
3. Literature review.................................................................................................................4
3.1. Natural products..............................................................................................................4
4. Objectives of the study .......................................................................................................8
5. Methodology.......................................................................................................................8
5.1. Design of target molecules..............................................................................................8
5.2. Retrosynthesis of target molecules................................................................................10
5.3. Chemical synthesis........................................................................................................11
5.3.1. Synthesis of acetylenic isatin, 21............................................................................11
5.3.2. Synthesis of O-alkylated aldehydes, 20a-c.............................................................11
5.3.3. Syntheis of O-alkylated chalcones, 19a-c ..............................................................12
5.3.4. Synthesis of azido chalcones, 18a-c.......................................................................12
5.3.5. Synthesis of triazoles, 17a-c...................................................................................12
5.4. Mechanisms...................................................................................................................13
5.4.1. Mechanism for aldol condensation.........................................................................13
5.4.2. Mechanism of the click reaction (1,3- dipolar cycloaddition)................................14
6. Results and discussion......................................................................................................15
6.1. Characterization ............................................................................................................18
10. 1
1. INTRODUCTION
According to the World Health Organization, approximately 80 % of the population in
developing countries relies almost entirely on plants for medication (Farnsworth, Akerele,
Bingel, Soejarto, & Guo, 1985). Natural products have been recognized as an important sources
of therapeutically effective medicines. They present a consistent, valuable source of drug leads
and provide greater structural diversity than compounds obtained through standard
combinatorial synthesis. Natural product research also offers major opportunities for finding
novel low molecular weight lead structures that are potentially active against a wide range of
assay targets (Dias, Urban, & Roessener, 2012).
Natural products play a key role in pharmaceutical research because many medicines are either
natural products or derivatives thereof. Indeed, it is estimated that about 40% of all medicines
is either natural products or their semi-synthetic derivatives (Jacob, 2009). Clinical,
pharmacological, and chemical studies of these traditional medicines, which were derived
predominantly from plants, were the basis of most early medicines such as aspirin (1),
morphine (2), quinine (3), pilocarpine (4) and digitoxin (5), figure 1 (Buttler, 2004).
Figure 1: Examples of medicines from plants
1 2 3
4 5
11. 2
Despite competition from other drug discovery methods, natural products are still providing
their fair share of new clinical candidates and drugs (Buttler, 2004). Therefore, in addition to
being a proven and important source of drug leads, natural products derived drugs also
contribute significantly to the profitability of many companies. Natural products research
continues to explore a variety of lead structures, which may be used as templates for the
development of new drugs by the pharmaceutical industry (Patwardhan, Vaidya, & Chorghade,
2004). In addition, natural products display structural diversity that can be exploited and will
therefore continue to play an important role in the discovery of new drugs (Shen, Xu, & Cheng,
2003).
Isatin (5, fig. 2), the natural product scaffold selected for this study, is an indole derivative (1H-
indole-2,3-dione) which is a synthetically versatile substrate. It was selected because it can be
used as the starting material for the synthesis of a large variety of heterocyclic compounds,
such as indoles and quinolines, and as raw material for drug synthesis (Abele, E. & Abele, R.,
2003). It was first obtained by Erdmann and Laurent in 1841 as a product from the oxidation
of indigo dye by nitric acid and chromic acids. It is also isolated from many plants namely
Isatis tictoria (from Central and Western Asia, eastern Siberia and some parts of Central
Europe), Calanthe discolor (Korea, Japan and China) and Couroupita guianesis (from Central
and South America).
Figure 2: Structure of isatin
The key focus of this study is therefore to use isatin as a template to design and synthesize
analogues modelled on it.
5
12. 3
2. MOTIVATION OF STUDY
Natural product-derived drugs have fewer side effects and are readily absorbed compared to
synthetic drugs (Esron, 2002). They are used as templates in drug discovery process because
they offer an opportunity for finding novel low molecular weight lead structures that are
potentially active against a wide range of assay targets (Dias, Urban, & Roessener, 2012).
Isatin, the chosen scaffold and its derivatives reportedly display antiviral activity against SARS
viruses. Previous work reported the inhibitory activity of isatin-β-thiosemicarbazones and
isatin derivatives against HIV replication (Banerjee, et al., 2011). The synthetic modification
of isatin and its derivatives may yield new and improved drugs with enhanced biological
properties.
HIV/AIDS and TB are infectious diseases responsible for a quarter of all deaths worldwide.
Africa has the highest burden of such diseases in the world (Kinghorn, et al., 2012). They were
the second main cause of mortality in the past few years, with HIV/AIDS (Acquired
Immunodeficiency Syndrome), for which there is no cure, being a major contributor. The
causative agents of these infectious diseases develop resistance against prescribed drugs,
therefore there is a need for new anti-infective drugs.
Analogues, briefly put, are chemical derivatives of natural products which, due to minor
structural changes, show a weaker or stronger activity than the parent compounds. It is
therefore envisaged that by synthesizing analogues a more efficient drug with a favorable
solubility/pharmacokinetic profile compared to the parent natural product may be generated.
13. 4
3. LITERATURE REVIEW
3.1. NATURAL PRODUCTS
Several drug candidates have been derived from different natural occurring sources, which can
be broadly divided into four categories as shown in figure 3 below.
Figure 3: Sources of natural products
Microorganisms, as a source of potential drug candidates, were not explored until the discovery
of penicillin in 1929. Since then, a large number of terrestrial and marine microorganisms have
been screened in drug discovery efforts. Microorganisms have a wide variety of potentially
active substances and have led to the discovery of anticancer agents like epirubicin (6, figure
4), (Chin, Balunas, Chai, & Kinghorn, 2006).
Figure 4: Example of a natural product isolated from a microorganism
The first active compounds to be isolated from marine species were spongouridine (7, figure
5) and spongothymidine (8, figure 5) from the Carribean sponge, Cryptotheca crypta in the
1950s. These compounds are nucleotides and show great potential as anticancer and antiviral
Natural Products
Microbes Plants Animals Marine organisms
6
14. 5
agents. Their discovery led to an extensive search for novel drug candidates from marine
sources. About 70 % of the earth’s surface is covered by the oceans, providing significant
biodiversity for exploration of drug sources. Many marine organisms have a sedentary lifestyle,
and thereby synthesize many complex and extremely potent chemicals as a means of defense
against predators (Haefner, 2006). These chemicals can serve as possible remedies for various
ailments, especially cancer. One such example is discodermolide (9, figure 5), isolated from
the marine sponge, Discodermia dissoluta, which has a strong antitumor activity (Huang, et
al., 2006).
Figure 5: Examples of natural products from marine organisms
Animals also serve as a source of drugs and drug leads. Epibatidine, an analgesic agent obtained
from the skin of an Ecuadorian poison frog, is ten times more potent than morphine (Koehn &
Carter, 2005). Venoms and toxins from animals have played a significant role in designing a
multitude of cures for several diseases. Teprotide, for example, extracted from a Brazilian
viper, has led to the development of cilazapril (10, figure 6) and captopril (11, figure 6), which
are effective for the treatment of hypertension (Koehn & Carter, 2005).
10 11
Figure 6: Examples of natural products from animal sources
7 8 9
15. 6
The use of plants as medicines has a long history in the treatment of various diseases. The
earliest known records for the use of plants as drugs stem from Mesopotamia in 2600 B.C.
(Koehn & Carter, 2005). Several important drugs such as taxol, camptothecin, morphine and
quinine (3, figure 1) were isolated from plant sources. The first two are widely used as anti-
cancer drugs, while the remaining are analgesic and antimalarial agents, respectively.
Probably the most famous and well known example to date would be the synthesis of the
anti-inflammatory agent, acetylsalicylic acid better known as aspirin (12, figure 7) derived
from the natural product, salicin and isolated from the bark of the willow tree Salix alba.
12
Figure 7: Example of a natural product from plant source
A literature study revealed that research on isatin and its derivatives were primarily focused on
evaluating their antimalarial (Raj, Gut, Rosenthal, & Kumar , 2014), antitubercular (Hans, et
al., 2011), anticancer (Han, et al., 2014), antitumor (Liang, et al., 2014), antiplasmodial (Hans,
Gut, Rosenthal, & Chibale, 2010) activities. Also reported are their antiviral activities,
specifically against pox virus, vaccinia, rhino virus, moleney leukemia virus and SARS viruses
(Banerjee, et al., 2011).
For the potential treatment of HIV-TB co-infections, an isatinyl thiosemicarbazones
derivatives 13 was found to be the most potent in inhibiting the replication of HIV-1 cells
(Banerjee, et al., 2011). Using lamivudine drug (14, figure 9), more potent analogues such as
15 were obtained. The antiviral activity of lamivudine and its prodrugs against HIV-1 was
determined in vitro in T4 lymphocytes (Sriram, Yogeeswari, & Gopal, 2005).
16. 7
13
Figure 8: Isatinyl thiosemicarbazone derivative
14 15
Figure 9: Lamivudine and its derivative
17. 8
4. OBJECTIVES OF THE STUDY
The objectives of this study are to:
Design analogues modelled on isatin
Synthesize isatin analogues
Characterize the synthesized analogues
5. METHODOLOGY
5.1. DESIGN OF TARGET MOLECULES
The target molecule was designed in such a way that the isatin scaffold was linked with a
chalcone through a triazole ring system and the ketonic carbonyl was reacted with a
semicabazide or thiosemicabazide to form a Schiff base (16).
Triazole linker
Chalcone
R= H, Cl
X= Semicarbazide, Thiosemicarbazide
Y= H, OCH3
Figure 10: Target molecule
For designing of the target molecules, the following reports were considered:
The isatin moiety is a scaffold which offers different sites for chemical modification.
Reference has been made to the broad spectrum of biological properties displayed by
its derivatives and its synthetic versatility (Raghu, et al., 2013).
16
18. 9
In recent years, Schiff and Mannich bases of isatin were reported to exhibit
chemotherapeutic properties including antiviral, antitubercular, antifungal, and
antibacterial activities. Investigation of the SARs of isatin derivatives revealed that 5-
halogenation, N-alkylation, N-Mannich base, and 3-thiosemicarbazone formation were
effective in triggering a marked rise in activity against various bacteria, fungi, and
viruses (Raghu, et al., 2013). Notably, Schiff bases of isatin have been reported to
possess anti-HIV, anticonvulsant, antibacterial, antiprotozoal, antifungal, anti-viral,
and anthelmintic activities (Chegyuan, et al., 2014).
Over the past few years the 1,2,3-triazole ring system and derivatives which contain
this ring system, have attracted a great deal of interest due to their diverse biological
activities such as antitubercular, anti-HIV, antifungal, antibacterial, and anticancer
activities. ‘Click chemistry’ allow for easy synthesis of this ring system. The favourable
properties of 1,2,3-triazole ring like moderate dipole character, hydrogen bonding
capability, rigidity and stability under in vivo conditions are evidently responsible for
enhanced biological activities. Moreover, the incorporation of 1,2,3-triazoles as a linker
of two pharmacophores to give bifunctional drugs, have become increasingly useful
and important in constructing bioactive molecules (Kewal, Sunir, Luke, Mandeep , &
Vipan, 2012).
Chalcones are of considerable interest in drug discovery because of the diverse
biological activities displayed by their derivatives and the ease and simplicity of their
synthesis. Moreover, this scaffold allows for the systematic variation of substituents
and or substitution patterns on the aromatic rings (Hans, Jiri, Rosenthal, & Chibale,
2010).
19. 10
5.2. RETROSYNTHESIS OF TARGET MOLECULES
5
Semicarbazide
18
Propargy bromide
R= H, Cl
Dibromoethane
Salicylaldehyde, a
4-hydroxybenzaldehyde, b
vanillin, c
16
20
Acetophenone
21
17
N-alkylation
Shiff base
formation
Click
reaction
Funtional Group
Interconversion
Aldol Condensation
O-alkylation
19
Scheme 1: Retrosynthesis of target molecule
Synthesis of target molecule 16 was envisaged through the Schiff base formation
reaction of semicarbazides or thiosemicarbazides with the ketonic carbonyl group of
intermediate 17. Intermediate 17 in turn can be obtained through the click reaction of the azido
chalcone 18 and the acetylenic isatin 21. The acetylenic isatin 21 can be obtained through N-
20. 11
alkylation of isatin with propargyl bromide. The azido chalcone 18 can be obtained through
functional group interconversion of the O-alkylated chalcone 19, and the latter can be accessed
through the Aldol condensation reaction of O-alkylated benzaldehyde derivative 20 and
acetophenone. O-alkylation of a benzaldehyde derivative with 1,2-dibromoethane will give 20.
Friedel’s-Craft acylation method was also attempted in order to synthesize the target molecule.
The method consisted of the acylation of acetanilide with acetyl chloride using anhydrous
AlCl3 as the catalyst and DCM as solvent. Unfortunately, no reaction occurred due to the poor
solubility of the aromatic substrate in the solvent. On the other hand, three target molecules
were envisaged using the procedure outlined above (scheme 1) but with different starting
benzaldehyde derivatives such as salicylaldehyde, 4-hydroxybenzaldehyde and vanillin.
5.3. CHEMICAL SYNTHESIS
5.3.1. SYNTHESIS OF ACETYLENIC ISATIN, 21
Sodium hydride, 60 % suspended in mineral oil (16.99 mmol, 1.5 eq) was added to
commercially available isatin (11.32 mmol, 1.0 eq) in 16.64 mL of anhydrous DMF at 0 °C.
The propargyl bromide, 80 % in toluene, (56.61 mmol, 4.0 eq) was added and the resulting
mixture slowly warmed to 25 °C. Stirring was continued for 1 hour at this temperature under
nitrogen atmosphere. The temperature was then increased to 60 °C and the reaction mixture
stirred for 24 hours at this temperature under nitrogen atmosphere. Ice-cold water was added
to the orange coloured reaction mixture and the precipitate that formed was filtered, washed
with water and recrystallized from MeOH to yield the pure product (Hans R. H., Novel
Antimalarial and Antitubercular Agents Based on Natural Products, 2009).
5.3.2. SYNTHESIS OF O-ALKYLATED ALDEHYDES, 20a-c
Anhydrous K2CO3 (8.50 g, 61.50 mmol, 1.5 eq) was added to a benzaldehyde derivative
(5.0 g, 40.94 mmol, 1.0 eq) dissolved in 25 mL anhydrous DMF and 1,2-dibromoethane, (9.2
g, 48.97 mmol, 1.2 eq) was added to the mixture. The resulting mixture was stirred for 16 hours
at 25 °C under nitrogen atmosphere. After reaction completion, as indicated by TLC, ice-
cold water was added to the reaction mixture. The obtained precipitate was filtered, washed
with water and recrystallized from MeOH to yield the pure product (Hans R. H., Novel
Antimalarial and Antitubercular Agents Based on Natural Products, 2009).
21. 12
5.3.3. SYNTHEIS OF O-ALKYLATED CHALCONES, 19a-c
To a solution of the O-alkylated benzaldehyde derivatives 20a-c (10.61 mmol, 1.0 eq) in MeOH
was added 8.5 mL of methanolic NaOH (3% w/v). The resulting mixture was stirred at room
temperature (at 25 °C) for 30 minutes. A methanolic solution of the commercially available,
acetophenone (10.61 mmol, 1.0 eq) was added and the mixture stirred overnight at the
same temperature under ambient atmosphere. The precipitate that formed was filtered and
washed with cold MeOH. Recrystallization from MeOH afforded the pure product (Hans R.
H., Novel Antimalarial and Antitubercular Agents Based on Natural Products, 2009).
5.3.4. SYNTHESIS OF AZIDO CHALCONES, 18a-c
Sodium azide (2.78 mmol, 2.0 eq) was added to a solution of O-alkylated chalcones, 19a-c
(1.39 mmol, 1.0 eq) in 3 mL of anhydrous DMF. The reaction mixture was stirred at 25 ºC for
18 hours under nitrogen atmosphere. The addition of ice-cold water to the product mixture
resulted in the formation of a precipitate which was filtered and washed with copious amounts
of water. Recrystallization from MeOH afforded the pure product (Hans R. H., Novel
Antimalarial and Antitubercular Agents Based on Natural Products, 2009).
5.3.5. SYNTHESIS OF TRIAZOLES, 17a-c
The azides, 18a-c (0.464 mmol, 1.0 eq) and acetylenic isatin 21 (0.510 mmol, 1.1 eq) were
dissolved in 3 mL of CH2Cl2:H2O (1:1). Copper (II) sulphate pentahydrate (0.0232 mmol, 5
mol %) and sodium ascorbate (0.0696 mmol, 15 mol %) was added to the mixture. The
resulting mixture was stirred for 16 hours at 25 °C under ambient atmosphere. Upon
completion, the product mixture was diluted with water and extracted with EtOAc. The
combined organic layer was washed with water and brine, dried over anhydrous Na2SO4 and
concentrated under reduced pressure to yield the product (Hans R. H., Novel Antimalarial and
Antitubercular Agents Based on Natural Products, 2009).
22. 13
5.4. MECHANISMS
5.4.1. MECHANISM FOR ALDOL CONDENSATION
- +
- OR
Na +
Na+
-
- NaOH
Na + -OH
-Na +
Scheme 2: Mechanism for Aldol condensation (Hans R. H., Novel Antimalarial and
Antitubercular Agents Based on Natural Products, 2009)
The mechanism for the Aldol condensation is depicted in scheme 2. It involves the base-
catalyzed enolization of acetophenone followed by nucleophilic attack of the enolate on the
O-alkylated benzaldehyde derivative. The β-hydroxy ketone so formed undergoes base
catalyzed elimination in a E1cB mechanism to yield the α,β-unsaturated chalcone.
23. 14
5.4.2. MECHANISM OF THE CLICK REACTION (1,3- DIPOLAR
CYCLOADDITION)
-H+
[CuLn]+
Ligand (L)
reducing agent
CuSO4
+H+
+
+ -
(i)
(ii)
(iii)
(iv)
Scheme 3: Proposed mechanism for the Cu(I)-catalyzed azide-acetylene cycloaddition 1
(1) Patton, G.C. Development and Application of Click Chemistry, 2004,
24. 15
6. RESULTS AND DISCUSSION
Table 1: Table of synthesized intermediates and target molecules
Intermediate/
Target
Molecule
Chemical
Formula
IUPAC
name
Novel or
Known
Melting
Point
(°C)
Rf
value
Yield
(%)
21
C11H7NO2
1-(prop-2-yn-1-
yl) indoline-2,3-
dione
Known 153
158 a
0.79
(EtOAc:
Hex 1:1)
37
20a
C9H9BrO2
2-(2-
bromoethoxy)
benzaldehyde
Known
125
52 b
0.27
(EtOAc:
Hex 3:7)
27
20b
C9H9BrO2
4-(2-
bromoethoxy)
benzaldehyde
Known
119
61 c
0.77
(EtOAc:
Hex)
53
20c
C10H11BrO3
4-(2-
bromoethoxy)-3-
methoxybenzald
ehyde
Known
178
b.p.356 d
0.73
(EtOAc:
Hex 3:1)
33
19a
C17H15BrO2
(E)-3-(2-(2-
bromoethoxy)
phenyl)-1-
phenylprop-2-en-
1-one
Novel 142-144
0.77
(EtOAc:
Hex 1:1)
95
26. 17
Intermediate/
Target Molecule
Chemical
Formula
IUPAC
name
Novel
or
Known
Melting
Point
(°C)
Rf
value
Yield
(%)
17a
C28H22N4O4
(E)-1-((1-(2-(2-
(3-oxo-3-
phenylprop-1-en-
1-
yl)phenoxy)ethyl
)-1H-1, 2, 3-
triazol-5-
yl)methyl)indoli
ne-2,3-dione
Novel 116
0.62
(MeOH :
DCM
0.2 : 9.8)
51
17b
C28H22N4O4
(E)-1-((1-(2-(4-
(3-oxo-3-
phenylprop-1-en-
1-
yl)phenoxy)ethyl
)-1H-1, 2, 3-
triazol-4-
yl)methyl)indoli
ne-2,3-dione
Novel 137
0.53
(MeOH :
DCM
0.2 : 9.8)
48
17c
C29H22N4O4
(E)-1-((1-(2-(2-
methyl-4-(3-oxo-
3-phenylprop-1-
en-1-
yl)phenoxy)ethyl
)-1H-1, 2, 3-
triazol-4-
yl)methyl)indoli
ne-2,3-dione
Novel 136
0.67
(MeOH :
DCM
0.2 : 9.8)
35
(a). Literature melting point (http://www.chemspider.com/Chemical-Structure.1468549.html (accessed 05:43, Oct 23, 2014)).
(b). Literature melting point (Zhao, Wang, Hu, Ma, & Wang, 2005)
(c). Literature melting point (Zhu, et al., 2014)
(d). Literature boiling point (http://www.chemspider.com/Chemical-Structure.12956958.html (accessed 05:56, Oct 23, 2014)).
27. 18
The yields of acetylenic isatin and the O-alkylated benzaldehydes might have been affected by
the nitrogen gas that was not 100 % dry. To obtain dry N2 gas, a drying tube filled with
anhydrous CaCl2 should have been connected to the nitrogen cylinder. On the other hand, for
the acetylenic isatin synthesis and the O-alkylated benzaldehyde synthesis, the reactions were
conducted for 24 hours at 60 °C and for 16 hours at 25 °C respectively and the presence of
moisture in the reaction mixture might have affected the yields.
The acetylenic isatin synthesized is a known compound and the melting point obtained from
the literature is approximately the same as the one measured. It can be concluded that the
proposed intermediate was indeed obtained. For the O-alkylated benzaldehyde derivatives, the
melting points in the literature have a very strong difference in their magnitudes and this may
be due to the impurities present in the synthesized intermediate.
The azido chalcone and the triazoles are all novel compounds and thus comparisons with
literature melting point values could not be done.
6.1. CHARACTERIZATION
6.1.1. SPECTROSCOPIC ANALYSIS
The spectroscopic data obtained for the desired intermediate 21 is consistent with the proposed
structure. Figures 11, 12 and 13 show the 1
H and 13
C NMR spectra of representative compound
21. The 1
H NMR data (figure 12) showed some key signals of the isatin scaffold appearing in
the aromatic region of the spectrum as multiplets resonating at 7.06 - 7.60 and integrating for
4 protons. These signals were assigned to H-4, H-5, H-6 and H-7. A pair of one-proton singlet
resonating at 4.5 was assigned to the methylene protons H-1’ a/b. The acetylenic proton, H-
3’, resonated at 2.3 and showed coupling to the methylene protons H-1’ a/b.
28. 19
Figure 11: 1
H NMR spectrum showing all signals of compound 21 in CDCl3 at 600 MHz
H-1’ a/b
H-3’
H-4, 7
H-5, 6
1
2
3
3a
4
5
6
7
7a
1'
2'
3'
29. 20
Figure 12: 1
H NMR spectrum showing all signals of compound 21 in CDCl3 at 600 MHz –
expansion of region 7.06 - 7.60
The 13
C NMR spectrum of compound 21 (figure 13) showed 11 non-equivalent signals which
correlates with the number of carbons expected for the proposed structure. Key signals at 160
and 185 were assigned to carbonyl carbons at C-2 and C3 respectively. Another carbon
signals of interest are the acetylenic carbon C-3’ resonating at 76 and the amine carbon C-1’
resonating at 35. The 13
C NMR spectrum also confirms the proposed structure of compound
21.
For the remaining intermediates samples were sent for 1
H and 13
C NMR analysis but
unfortunately the spectra are not available yet.
H-4, 7 H-5, 6
1
2
3
3a
4
5
6
7
7a
1'
2'
3'
31. 22
7. CONCLUSION
In this study, the analogues modelled on isatin have successfully been designed,
synthesized and characterized. The Schiff bases were not synthesized due to time
constraint. The objectives stated for this study were partially fulfilled and therefore it can
be said that the research was successful. A recommendation for the improvement of yields
is that all the nitrogen gas should be completely dry and the reaction medium completely
free of moisture.
For the way forward after all structure confirmation of the analogues, this includes the
advance intermediates and target molecules, will be submitted for testing of inhibitory
activity against HIV protease and reverse transcriptase at the Chemistry and Biochemistry
Department (UNAM)).
32. 23
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