Synthesis of substituted 1, 2, 4-triazole derivatives by Microwave irradiationIOSR Journals
Various substituted Triazole-Thiol containing different functional group have been synthesized by microwave method. The title product 1-[(3H-indol-2-ylamino) methyl]-4-phenyl-4, 5-dihydro-1H-1, 2, 4-triazole-3-thiol is synthesized by using amino benzothiazole. The final structures have been established on the basis of their chemical analysis and spectral data. All micro-wave synthesized compounds results into good yield as compared to conventional method of which fluoro substituted compound shows maximum yield.
Synthesis of substituted 1, 2, 4-triazole derivatives by Microwave irradiationIOSR Journals
Various substituted Triazole-Thiol containing different functional group have been synthesized by microwave method. The title product 1-[(3H-indol-2-ylamino) methyl]-4-phenyl-4, 5-dihydro-1H-1, 2, 4-triazole-3-thiol is synthesized by using amino benzothiazole. The final structures have been established on the basis of their chemical analysis and spectral data. All micro-wave synthesized compounds results into good yield as compared to conventional method of which fluoro substituted compound shows maximum yield.
An efficient synthesis, characterization and antibacterial activity of novel ...iosrjce
IOSR Journal of Applied Chemistry (IOSR-JAC) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of applied chemistry and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in Chemical Science. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Preparation and Antimicrobial Studies of Oxadiazine Containing Heterocyclic C...ijtsrd
The triazole derivative say 2 3 methylthio 5 phenyl 4H 1,2,4 triazol 4 yl acetohydrazide 1 was prepared. Various Schiff bases 3a e of 1 were prepared by reacting with various benzaldehyde derivatives 2a e . All the 3a e compounds condensed with benzoyl isothiocyanate 4 to afford N 2 aryl 6 phenyl 4 thioxo 2H 1,3,5 oxadiazin 3 4H yl 2 3 methylthio 5 phenyl 4H 1,2,4 triazol 4 yl acetamide derivatives 5a e . All the synthesized compounds characterized spectroscopically and tested for antimicrobial activity. Reeta Tripathi | Diwa Mishra | Arun Singh "Preparation and Antimicrobial Studies of Oxadiazine Containing Heterocyclic Compounds" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd25349.pdfPaper URL: https://www.ijtsrd.com/chemistry/other/25349/preparation-and-antimicrobial-studies-of-oxadiazine-containing-heterocyclic-compounds/reeta-tripathi
Micellar Effect On Dephosphorylation Of Bis-4-Chloro-3,5-Dimethylphenylphosph...IOSR Journals
The rate enhancement depends on the hydrophobicity of the nucleophile. The micellar catalyzed reaction between bis-4-chloro-3,5-dimethylphenylphosphate ester and hydroxide or hydroperoxide anions has been examined in buffered medium (pH 8-10). First order rate constant (Kψ) for the reaction of hydroxide ion with bis-4-CDMPP go through maxima with the increasing concentration of cetyltrimethylammoniumbromide (CTABr). Micelles of CTABr very effective catalyst to the reactions of phosphate diesters. Rate constants measured with OH2- ions are approximately twice and thrice than that of OH- ions in presence of CTABr.
Microwave Irradated Synthesis, Characterization and Evaluation for their Antibacterial and Larvicidal Activities of some Novel Chalcone and Isoxazole Substituted 9-Anilino Acridines
SYNTHESIS OF OXAZIPEN COMPOUNDS VIA SCHIFF BASESJing Zang
This work involved preparation of cyclic compounds are containing of more than one hetero atoms in their structures like (N)-nitrogen atom. A seven-member ring compounds were prepared by condensation of N,N-di methyl amino benzaldehyde with aromatic amines to give compounds [N2-N17], these compounds were found to react with maleic anhydride to give 7-memberd ring [N18-N32]. All these compounds [N2- N32] were prepared by pericyclic reactions.
Synthesis, Characterization, Spectral (FT-IR, 1H, 13C NMR, Mass and UV) and B...Dr. Pradeep mitharwal
Bio-potent ligands, 2-hydroxy-N-phenylbenzamide hydrazinecarbothioamide(HPHTSCZH2) and 2-hydroxy-N-phenylbenzamide hydrazine carbodithioic benzyl ester (HPHCBESH2) have been synthesized by the condensation of 2-hydroxy-N-phenylbenzamide with hydrazinecarbothioamide and hydrazine carbodithioic benzyl ester, respectively and reacted with hydrated lanthanide chlorides. The coordination moieties of the ligands have been confirmed by various spectral studies. - See more at: http://www.sciencedomain.org/abstract.php?iid=271&id=16&aid=2488#sthash.6v3aFQIi.dpuf
Acoustic Parameters of acetic acid in benzene at 3 MHz.theijes
In present study, Ultrasonic velocity (U) and density (ρ) for binary liquid mixtures of acetic acid with benzene have been measured at 3 MHz ultrasonic frequency at 303K. From this data, acoustic parameters such as adiabatic compressibility (βad), acoustic impedance (Z), relative association (RA) and intermolecular free length (Lf) are calculated. The result is interpreted as per molecular interaction between the mixtures.
A STUDY TO EVALUATE THE IN VITRO ANTIMICROBIAL ACTIVITY AND ANTIANDROGENIC E...Dr. Pradeep mitharwal
The present paper deals with synthesis and characterization
of some new chromium (III) Schiff base complexes using microwave irradiation
technique as well as conventional heating. The S∩N donor benzothiazolines, 1-
(2-furanyl) ethanone benzothiazoline (Bzt1N
∩
SH), 1-(2-thienyl) ethanone
benzothiazoline (Bzt2N
∩
SH) and 1-(2-pyridyl) ethanone benzothiazoline
(Bzt3N
∩
SH) were prepared by the condensation of ortho-aminothiophenol with
respective ketones in ethanol.
An Efficient Synthetic Approach Towards 4-Cyano-3-(Methylthio)-5-Oxo-2H-Pyraz...inventionjournals
ABSTRACT: Synthesis of novel heterocyclic 4-cyano -3-(methylthio)-5-oxo-2H-pyrazole-1(5H)- carbothioamide (3) was prepared by condensing ethyl-2-cyano-3,3-bis (methylthio)acrylate (1) with thiosemicarbazide (2) in DMF and catalytic amount of potassium carbonate. Compound (3) has methylthio group at third position, which is replaced by different nucleophiles such as substituted anilines| phenols| hetryl amines| compounds containing active methylene group to afford 3-substituted derivatives of compound (3). All the newly synthesized compounds were screened for their antimicrobial activity.
Synthesis of 1,2,3-Triazole 5-Chloroisatin Derivatives via Copper-Catalyzed 1...IJAEMSJORNAL
A facile and simple protocol for the ‘Click’ cycloaddition of organic azides with N-propargylchloroisatine catalyzed by CuI, produces in good yields novel of 1,4-disubstituted 1,2,3-triazoles were obtained. Compared to the uncatalyzed cycloaddition, the yields are significantly improved in the presence of CuI as catalyst, without alteration of the selectivity. The regio- and stereochemistry of the cycloadducts has been corroborated by 1H, 13C NMR spectroscopy.
Theoretical investigation of the Structure Activity Relationships (SARs) of a...IJERA Editor
Theoretical study of a series of isomeric α-, β-, γ-, δ-, ε-RuCl2L2 (L= azpy, tazpy, 4mazpy, 5mazpy) complexes is carried out using the density functional theory (DFT) method at B3LYP/LanL2DZ level. The effects of the ligand on the electronic structures and related properties, e.g. the components and the energies of some frontier molecular orbital, the net charge populations of some main atoms of the complexes, the effect of substituent methyl as well as the Structure Activity-Relationships (SARs) of the complexes were investigated. The results show that the sterical differences between isomeric structures of these complexes have serious influence on their electronic structures and related properties. First and foremost, the geometric configuration of δ-Cl and γ-Cl isomers must be advantageous to the conjugative ligand to intercalate between DNA-base-pairs in comparison with α-Cl, β-Cl and ε-Cl complexes. Secondly, the energy order of the lowest unoccupied molecular orbital (LUMO) of the isomers is ELUMO(δ-Cl) < ELUMO(γ-Cl) < ELUMO(ε-Cl) < ELUMO(α-Cl) < ELUMO(β-Cl). And their HOMO-LUMO gap energy is classified as ΔE(δ-Cl) < ΔE(γ-Cl) < ΔE(ε-Cl)< ΔE(α-Cl)< ΔE(β-Cl). Thirdly, the dipole moments (µ) of the isomers, expressing the hydrophobic parameters of the molecules, was also classified as μ(ε-Cl) > μ(β-Cl) > μ(α-Cl) > μ(γ-Cl) > μ(δ-Cl). Finally, the net charge of the ligands azopyridine that defines the aptitude for the ligand to accept the electron from DNA, are classified as QL(δ-Cl) > QL(γ-Cl) > QL(ε-Cl) > QL(α-Cl) >QL(β-Cl). These electronic and geometric structural characteristics can be used to explain the trend in the anticancer-activities (A) of isomeric α-, β-, γ- RuCl2L2 (L= azpy, tazpy, 4mazpy) or to predict the order of activity of the five δ-Cl, γ-Cl, α-Cl, β-Cl and ε-Cl isomers of the three complexes RuCl2(azpy)2, RuCl2(tazpy)2 and RuCl2(4mazpy)2. They are also suitable to predict the activity of five non synthesized isomers of RuCl2(5mazpy)2 since the three azopyridine ligands tazpy, 4mazpy and 5mazpy display the same number of electrons.
Catalytic Conversion of Biomass using Solid Acid Catalystspbpbms6
The processes for synthesis of several value-added chemicals from biomass (hemicellulose and ignin) using solid acid catalysts are documented in this presentation. Particularly, C5 sugars and furfural are synthesized from hemicellulose and various aromatic monomers are obtained from lignin.
Detailed characterization of saponins isolated from Zygophyllum Propinqueem D...Open Access Research Paper
Zygophyllum propinquum Decne (syn. Z. coccineum, family: Zygophyllaceae) is a low shrub, perennial herb, or desert succulent undershrub and has several important biological activities. The major secondary metabolites of this plant are a class of ursane-type triterpene saponins. Saponins derive their name from stable foam formation in water. These saponins have peculiar properties like, bitterness, fish poisoning, haemolysis, complex formation with cholesterol. Saponins are consisting of two main parts, one is the aglycone part while the other one is the glycone part. The glycone part is further consisting of sugar moieties. Current studies were conducted to isolate specifically biologically important saponins. Saponins were isolated successfully using standard procedures and characterized successfully using different spectroscopic techniques including Fourier Transform-Infrared Spectroscopy, Mass Spectrometry and Nuclear Magnetic Resonance Spectroscopy. Two saponins were isolated from the whole plant of Zygophyllum propinquum Decne with the help of repeated column chromatography and HPLC. The purified saponins were hydrolyzed with H2SO4-dioxane resulting in lactone formation. All the compounds (saponins and lactone) were characterized with the help of FAB-MS and 1D and 2D-NMR techniques. Their structures were confirmed to be 3-O–β-D-glucopyranosyl-(1→6)- β-D-2-O-sulfo-glucuronopyranosylurs-20(21)-en28 oic acid 28-O-[β-D-glucuronopyranosyl] ester (1), (3β–O-2-O-sulfo-β-D-glucuronopyranosylurs-20(21)-en28 oic acid 28-O-[β-D-2-O-sulfonylglucuronopyranosyl] ester (2), and 3β-Hydroxy urs-28,20 β-olide (3).
The IOSR Journal of Pharmacy (IOSRPHR) is an open access online & offline peer reviewed international journal, which publishes innovative research papers, reviews, mini-reviews, short communications and notes dealing with Pharmaceutical Sciences( Pharmaceutical Technology, Pharmaceutics, Biopharmaceutics, Pharmacokinetics, Pharmaceutical/Medicinal Chemistry, Computational Chemistry and Molecular Drug Design, Pharmacognosy & Phytochemistry, Pharmacology, Pharmaceutical Analysis, Pharmacy Practice, Clinical and Hospital Pharmacy, Cell Biology, Genomics and Proteomics, Pharmacogenomics, Bioinformatics and Biotechnology of Pharmaceutical Interest........more details on Aim & Scope).
All manuscripts are subject to rapid peer review. Those of high quality (not previously published and not under consideration for publication in another journal) will be published without delay.
This Journal publishes original research work that contributes significantly to further the scientific knowledge in pharmacy.
An efficient synthesis, characterization and antibacterial activity of novel ...iosrjce
IOSR Journal of Applied Chemistry (IOSR-JAC) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of applied chemistry and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in Chemical Science. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Preparation and Antimicrobial Studies of Oxadiazine Containing Heterocyclic C...ijtsrd
The triazole derivative say 2 3 methylthio 5 phenyl 4H 1,2,4 triazol 4 yl acetohydrazide 1 was prepared. Various Schiff bases 3a e of 1 were prepared by reacting with various benzaldehyde derivatives 2a e . All the 3a e compounds condensed with benzoyl isothiocyanate 4 to afford N 2 aryl 6 phenyl 4 thioxo 2H 1,3,5 oxadiazin 3 4H yl 2 3 methylthio 5 phenyl 4H 1,2,4 triazol 4 yl acetamide derivatives 5a e . All the synthesized compounds characterized spectroscopically and tested for antimicrobial activity. Reeta Tripathi | Diwa Mishra | Arun Singh "Preparation and Antimicrobial Studies of Oxadiazine Containing Heterocyclic Compounds" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd25349.pdfPaper URL: https://www.ijtsrd.com/chemistry/other/25349/preparation-and-antimicrobial-studies-of-oxadiazine-containing-heterocyclic-compounds/reeta-tripathi
Micellar Effect On Dephosphorylation Of Bis-4-Chloro-3,5-Dimethylphenylphosph...IOSR Journals
The rate enhancement depends on the hydrophobicity of the nucleophile. The micellar catalyzed reaction between bis-4-chloro-3,5-dimethylphenylphosphate ester and hydroxide or hydroperoxide anions has been examined in buffered medium (pH 8-10). First order rate constant (Kψ) for the reaction of hydroxide ion with bis-4-CDMPP go through maxima with the increasing concentration of cetyltrimethylammoniumbromide (CTABr). Micelles of CTABr very effective catalyst to the reactions of phosphate diesters. Rate constants measured with OH2- ions are approximately twice and thrice than that of OH- ions in presence of CTABr.
Microwave Irradated Synthesis, Characterization and Evaluation for their Antibacterial and Larvicidal Activities of some Novel Chalcone and Isoxazole Substituted 9-Anilino Acridines
SYNTHESIS OF OXAZIPEN COMPOUNDS VIA SCHIFF BASESJing Zang
This work involved preparation of cyclic compounds are containing of more than one hetero atoms in their structures like (N)-nitrogen atom. A seven-member ring compounds were prepared by condensation of N,N-di methyl amino benzaldehyde with aromatic amines to give compounds [N2-N17], these compounds were found to react with maleic anhydride to give 7-memberd ring [N18-N32]. All these compounds [N2- N32] were prepared by pericyclic reactions.
Synthesis, Characterization, Spectral (FT-IR, 1H, 13C NMR, Mass and UV) and B...Dr. Pradeep mitharwal
Bio-potent ligands, 2-hydroxy-N-phenylbenzamide hydrazinecarbothioamide(HPHTSCZH2) and 2-hydroxy-N-phenylbenzamide hydrazine carbodithioic benzyl ester (HPHCBESH2) have been synthesized by the condensation of 2-hydroxy-N-phenylbenzamide with hydrazinecarbothioamide and hydrazine carbodithioic benzyl ester, respectively and reacted with hydrated lanthanide chlorides. The coordination moieties of the ligands have been confirmed by various spectral studies. - See more at: http://www.sciencedomain.org/abstract.php?iid=271&id=16&aid=2488#sthash.6v3aFQIi.dpuf
Acoustic Parameters of acetic acid in benzene at 3 MHz.theijes
In present study, Ultrasonic velocity (U) and density (ρ) for binary liquid mixtures of acetic acid with benzene have been measured at 3 MHz ultrasonic frequency at 303K. From this data, acoustic parameters such as adiabatic compressibility (βad), acoustic impedance (Z), relative association (RA) and intermolecular free length (Lf) are calculated. The result is interpreted as per molecular interaction between the mixtures.
A STUDY TO EVALUATE THE IN VITRO ANTIMICROBIAL ACTIVITY AND ANTIANDROGENIC E...Dr. Pradeep mitharwal
The present paper deals with synthesis and characterization
of some new chromium (III) Schiff base complexes using microwave irradiation
technique as well as conventional heating. The S∩N donor benzothiazolines, 1-
(2-furanyl) ethanone benzothiazoline (Bzt1N
∩
SH), 1-(2-thienyl) ethanone
benzothiazoline (Bzt2N
∩
SH) and 1-(2-pyridyl) ethanone benzothiazoline
(Bzt3N
∩
SH) were prepared by the condensation of ortho-aminothiophenol with
respective ketones in ethanol.
An Efficient Synthetic Approach Towards 4-Cyano-3-(Methylthio)-5-Oxo-2H-Pyraz...inventionjournals
ABSTRACT: Synthesis of novel heterocyclic 4-cyano -3-(methylthio)-5-oxo-2H-pyrazole-1(5H)- carbothioamide (3) was prepared by condensing ethyl-2-cyano-3,3-bis (methylthio)acrylate (1) with thiosemicarbazide (2) in DMF and catalytic amount of potassium carbonate. Compound (3) has methylthio group at third position, which is replaced by different nucleophiles such as substituted anilines| phenols| hetryl amines| compounds containing active methylene group to afford 3-substituted derivatives of compound (3). All the newly synthesized compounds were screened for their antimicrobial activity.
Synthesis of 1,2,3-Triazole 5-Chloroisatin Derivatives via Copper-Catalyzed 1...IJAEMSJORNAL
A facile and simple protocol for the ‘Click’ cycloaddition of organic azides with N-propargylchloroisatine catalyzed by CuI, produces in good yields novel of 1,4-disubstituted 1,2,3-triazoles were obtained. Compared to the uncatalyzed cycloaddition, the yields are significantly improved in the presence of CuI as catalyst, without alteration of the selectivity. The regio- and stereochemistry of the cycloadducts has been corroborated by 1H, 13C NMR spectroscopy.
Theoretical investigation of the Structure Activity Relationships (SARs) of a...IJERA Editor
Theoretical study of a series of isomeric α-, β-, γ-, δ-, ε-RuCl2L2 (L= azpy, tazpy, 4mazpy, 5mazpy) complexes is carried out using the density functional theory (DFT) method at B3LYP/LanL2DZ level. The effects of the ligand on the electronic structures and related properties, e.g. the components and the energies of some frontier molecular orbital, the net charge populations of some main atoms of the complexes, the effect of substituent methyl as well as the Structure Activity-Relationships (SARs) of the complexes were investigated. The results show that the sterical differences between isomeric structures of these complexes have serious influence on their electronic structures and related properties. First and foremost, the geometric configuration of δ-Cl and γ-Cl isomers must be advantageous to the conjugative ligand to intercalate between DNA-base-pairs in comparison with α-Cl, β-Cl and ε-Cl complexes. Secondly, the energy order of the lowest unoccupied molecular orbital (LUMO) of the isomers is ELUMO(δ-Cl) < ELUMO(γ-Cl) < ELUMO(ε-Cl) < ELUMO(α-Cl) < ELUMO(β-Cl). And their HOMO-LUMO gap energy is classified as ΔE(δ-Cl) < ΔE(γ-Cl) < ΔE(ε-Cl)< ΔE(α-Cl)< ΔE(β-Cl). Thirdly, the dipole moments (µ) of the isomers, expressing the hydrophobic parameters of the molecules, was also classified as μ(ε-Cl) > μ(β-Cl) > μ(α-Cl) > μ(γ-Cl) > μ(δ-Cl). Finally, the net charge of the ligands azopyridine that defines the aptitude for the ligand to accept the electron from DNA, are classified as QL(δ-Cl) > QL(γ-Cl) > QL(ε-Cl) > QL(α-Cl) >QL(β-Cl). These electronic and geometric structural characteristics can be used to explain the trend in the anticancer-activities (A) of isomeric α-, β-, γ- RuCl2L2 (L= azpy, tazpy, 4mazpy) or to predict the order of activity of the five δ-Cl, γ-Cl, α-Cl, β-Cl and ε-Cl isomers of the three complexes RuCl2(azpy)2, RuCl2(tazpy)2 and RuCl2(4mazpy)2. They are also suitable to predict the activity of five non synthesized isomers of RuCl2(5mazpy)2 since the three azopyridine ligands tazpy, 4mazpy and 5mazpy display the same number of electrons.
Catalytic Conversion of Biomass using Solid Acid Catalystspbpbms6
The processes for synthesis of several value-added chemicals from biomass (hemicellulose and ignin) using solid acid catalysts are documented in this presentation. Particularly, C5 sugars and furfural are synthesized from hemicellulose and various aromatic monomers are obtained from lignin.
Detailed characterization of saponins isolated from Zygophyllum Propinqueem D...Open Access Research Paper
Zygophyllum propinquum Decne (syn. Z. coccineum, family: Zygophyllaceae) is a low shrub, perennial herb, or desert succulent undershrub and has several important biological activities. The major secondary metabolites of this plant are a class of ursane-type triterpene saponins. Saponins derive their name from stable foam formation in water. These saponins have peculiar properties like, bitterness, fish poisoning, haemolysis, complex formation with cholesterol. Saponins are consisting of two main parts, one is the aglycone part while the other one is the glycone part. The glycone part is further consisting of sugar moieties. Current studies were conducted to isolate specifically biologically important saponins. Saponins were isolated successfully using standard procedures and characterized successfully using different spectroscopic techniques including Fourier Transform-Infrared Spectroscopy, Mass Spectrometry and Nuclear Magnetic Resonance Spectroscopy. Two saponins were isolated from the whole plant of Zygophyllum propinquum Decne with the help of repeated column chromatography and HPLC. The purified saponins were hydrolyzed with H2SO4-dioxane resulting in lactone formation. All the compounds (saponins and lactone) were characterized with the help of FAB-MS and 1D and 2D-NMR techniques. Their structures were confirmed to be 3-O–β-D-glucopyranosyl-(1→6)- β-D-2-O-sulfo-glucuronopyranosylurs-20(21)-en28 oic acid 28-O-[β-D-glucuronopyranosyl] ester (1), (3β–O-2-O-sulfo-β-D-glucuronopyranosylurs-20(21)-en28 oic acid 28-O-[β-D-2-O-sulfonylglucuronopyranosyl] ester (2), and 3β-Hydroxy urs-28,20 β-olide (3).
The IOSR Journal of Pharmacy (IOSRPHR) is an open access online & offline peer reviewed international journal, which publishes innovative research papers, reviews, mini-reviews, short communications and notes dealing with Pharmaceutical Sciences( Pharmaceutical Technology, Pharmaceutics, Biopharmaceutics, Pharmacokinetics, Pharmaceutical/Medicinal Chemistry, Computational Chemistry and Molecular Drug Design, Pharmacognosy & Phytochemistry, Pharmacology, Pharmaceutical Analysis, Pharmacy Practice, Clinical and Hospital Pharmacy, Cell Biology, Genomics and Proteomics, Pharmacogenomics, Bioinformatics and Biotechnology of Pharmaceutical Interest........more details on Aim & Scope).
All manuscripts are subject to rapid peer review. Those of high quality (not previously published and not under consideration for publication in another journal) will be published without delay.
This Journal publishes original research work that contributes significantly to further the scientific knowledge in pharmacy.
Switching Off and On the Supramolecular Chiral Memory in PorphyrinAngela Mammana
we have reported here an example of a totally
noncovalent memory system able to cycle between “written” and
“erased” states. We think that this example opens the route for a
general approach and new pathways to design systems able to
memorize imprinted chiral information and successively cycle
between erased and rewritten states
SIMONA CAVALU_EPR study of non covalent spin labeled serum albumin and haemog...Simona Cavalu
Abstract
Electron Paramagnetic Resonance (EPR) was used to investigate the Tempyo spin label (3-carbamoyl-2,2,5,5-
tetramethyl-3-pyrrolin-1-yloxy) as a report group for the interactions and the conformational changes of lyophilized
bovine serum albumin (BSA) and bovine hemoglobin (BH), as function of pH values in the range 2.5–11. The EPR
spectra are similar with those of other non-covalently spin label porphyrins in frozen solution at very low temperatures.
This behavior indicated a possible spin–spin interaction between the hemic iron and the nitroxide group. The changes
in the EPR spectra as function of the pH are discussed in terms of conformational changes of the proteins. Spectral
simulations and magnetic EPR parameters reveal the following: (i) one single paramagnetic species, with Gaussian
line shape, was used for the best fits of experimental spectra in the case of serum albumin samples; and (ii) a
weighted sum of Lorentzian and Gaussian line shape in the case of hemoglobin samples. The representation of
correlation time vs. pH, reveals a dependence of degree of immobilization of spin label on the conformational changes
of proteins in acidic and basic environment.
The norm of elastic constant tensor and the norms of the irreducible parts of the elastic constants of
Intermetallic compounds are calculated. The relation of the scalar parts norm and the other parts norms
and the anisotropy of these compounds are presented. The norm ratios are used to study anisotropy of
these compounds.
Computational NMR Characterization of Chiral Au25(SMeBut)18Svetlana Gelpi
Can NMR calculations be used as fingerprints for the determination of structural features in Monolayer Protected Clusters (MPCs)? The effect of the chiral 2-methyl-1-butanethiol (SMeBut) ligand on the inherently achiral Au25 nanocluster system Au25(SMeBut)180, is being studied. To explain the unique features found in the 1H NMR spectra as a function of decreasing enantiomeric excess (e.e.) percentage, we are using computational spectroscopic characterization. One of the unique features to this cluster is that when the e.e. of the ligand is systematically changed the 1H NMR peak for the α-methylene protons evolves by splitting and broadening. We are currently investigating the origin of such splitting. Computational methods involving quantum chemistry and molecular dynamics simulations may be able to answer these questions. Currently, our results agree with experiment in terms of the maximum peak for the -methylene protons for 100% S enantiomer. Our hypothesis is that as the e.e. is changed, steric constraints lock specific populations of ligand conformations throughout the systems monolayer.