Introduction, classification, isolation, purification, biological activity of alkaloids, general methods of structural determination of alkaloids, structural elucidation of Morphine, Reserpine and Emetine
Introduction, classification, isolation, purification, biological activity of alkaloids, general methods of structural determination of alkaloids, structural elucidation of Morphine, Reserpine and Emetine
Alkaloids are a group of naturally occurring chemical compounds that mostly contain basic nitrogen atoms.
The term alkaloid was coined by Meissner, a German pharmacist, in 1819.
Alkaloids are cyclic organic compounds containing nitrogen in a negative state of oxidation with limited distribution among living organisms.
Most alkaloids contain oxygen in their molecular structure; those compounds are usually colorless crystals at ambient conditions.
Some alkaloids are colored, like berberine (yellow) and sanguinarine (orange).
Most alkaloids are weak bases, but some, such as theobromine and theophylline, are amphoteric.
Many alkaloids dissolve poorly in water but readily dissolve in organic solvents.
Most alkaloids have a bitter taste or are poisonous when ingested.
THIS SLIDE HAVE GOOD CONTENT. THIS SLIDE CONTAIN INTRODUCTION, STRUCTURE, RESONANCE, AROMATICITY, PHYSICAL AND CHEMICAL PROPERTIES, SYNTHESIS AND APPLICATION OF QUINOLINE.
Alkaloids are a group of naturally occurring chemical compounds that mostly contain basic nitrogen atoms.
The term alkaloid was coined by Meissner, a German pharmacist, in 1819.
Alkaloids are cyclic organic compounds containing nitrogen in a negative state of oxidation with limited distribution among living organisms.
Most alkaloids contain oxygen in their molecular structure; those compounds are usually colorless crystals at ambient conditions.
Some alkaloids are colored, like berberine (yellow) and sanguinarine (orange).
Most alkaloids are weak bases, but some, such as theobromine and theophylline, are amphoteric.
Many alkaloids dissolve poorly in water but readily dissolve in organic solvents.
Most alkaloids have a bitter taste or are poisonous when ingested.
THIS SLIDE HAVE GOOD CONTENT. THIS SLIDE CONTAIN INTRODUCTION, STRUCTURE, RESONANCE, AROMATICITY, PHYSICAL AND CHEMICAL PROPERTIES, SYNTHESIS AND APPLICATION OF QUINOLINE.
Plants produce a vast and diverse organic compounds, which do not appear to participate directly in growth and development.These substances traditionally referred to as secondary metabolites which terpenes are one of them.
Drug development for neglected parasitic diseases. Group of the University of Barcelona offers expertise from the design and synthesis of new therapeutic membrane active peptide-based antibiotics (AMP, NCE) to in vivo proof-of-concept and MoA (TEM, AFM, flow cytometry, fluorescence...).
Study material for chemistry UG and PG students
Chapter No 05 Terpenoids, Study of natural product Chemistry of natural products, Pharmaceutical chemistry.
Terpenoids for slide presentation new 1.pptxpravin bendle
Terpenoids are a group of naturally occurring compounds responsible for the aroma, taste, and occasionally the color of plants & found extensively in the leaves and fruits of plants like conifers, citrus, and eucalyptus.
Terpenes are hydrocarbons of plant origin of the general formula (C5H8)n and their oxygenated, hydrogenated, and dehydrogenated derivatives are known as terpenoids
On the thermal decomposition of Terpenoids ( isoprenoids) yield isoprene.
The special isoprene rule states that in most naturally occurring terpenes two or more isoprene units are linked to one another usually in a “head to tail” manner.(1- 4 link)
Terpenoids are classified on the basis of no of isoprene units in the molecule.
Natural products and chemical products differ in several ways, including their origin, composition, production methods, and potential applications. Here are some key differences between the two:
Origin:
Natural Products: These are derived from natural sources, such as plants, animals, microorganisms, or minerals. Examples include herbal remedies, essential oils, and food products.
Chemical Products: These are synthesized in laboratories or chemical factories. They are typically created through chemical reactions and processes.
Composition:
Natural Products: They often contain a complex mixture of naturally occurring compounds, and their composition can vary based on the source and environmental factors. These products may contain a combination of chemicals produced by living organisms.
Chemical Products: They are typically composed of pure or well-defined chemical compounds. Their composition is consistent and can be precisely controlled.
Production Methods:
Natural Products: Obtained through extraction, purification, or isolation processes from natural sources. The methods may involve techniques like distillation, solvent extraction, or fermentation.
Chemical Products: Synthesized through chemical reactions involving various reagents and catalysts in controlled laboratory conditions. These reactions are typically reproducible.
Purity:
Natural Products: May contain impurities or variations in composition due to the natural source. Purity levels can vary significantly.
Chemical Products: Can be highly purified, with known and consistent chemical compositions.
Safety and Regulation:
Natural Products: May be subject to fewer regulations, leading to potential variability in safety and efficacy. Some natural products may also have potential side effects or interactions with medications.
Chemical Products: Typically subject to rigorous safety testing and regulatory oversight, which helps ensure a certain level of safety and efficacy.
Environmental Impact:
Natural Products: May have a lower environmental impact if sourced sustainably, but overharvesting or unsustainable practices can lead to ecological harm.
Chemical Products: The production of chemicals can have environmental consequences, including the generation of waste and pollution. However, sustainable and green chemistry practices aim to mitigate these impacts.
Applications:
Natural Products: Often used in traditional medicine, cosmetics, food, and some pharmaceuticals. They are favored for their perceived natural and holistic qualities.
Chemical Products: Widely used in various industries, including pharmaceuticals, plastics, agriculture, and electronics. They can be designed for specific purposes and are essential in modern manufacturing and technology.
It's important to note that both natural and chemical products have their own advantages and disadvantages, and the choice between them often depends on factors like safety, efficacy, cost, sustainability,
Terpenoids are volatile substances which give plants and flowers their fragrance. They occur widely in the leaves and fruits of higher plants, conifers, citrus and eucalyptus. The term ‘terpene’ was given to the compounds isolated from terpentine, a volatile liquid isolated from pine trees.
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
The prostate is an exocrine gland of the male mammalian reproductive system
It is a walnut-sized gland that forms part of the male reproductive system and is located in front of the rectum and just below the urinary bladder
Function is to store and secrete a clear, slightly alkaline fluid that constitutes 10-30% of the volume of the seminal fluid that along with the spermatozoa, constitutes semen
A healthy human prostate measures (4cm-vertical, by 3cm-horizontal, 2cm ant-post ).
It surrounds the urethra just below the urinary bladder. It has anterior, median, posterior and two lateral lobes
It’s work is regulated by androgens which are responsible for male sex characteristics
Generalised disease of the prostate due to hormonal derangement which leads to non malignant enlargement of the gland (increase in the number of epithelial cells and stromal tissue)to cause compression of the urethra leading to symptoms (LUTS
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
Acute scrotum is a general term referring to an emergency condition affecting the contents or the wall of the scrotum.
There are a number of conditions that present acutely, predominantly with pain and/or swelling
A careful and detailed history and examination, and in some cases, investigations allow differentiation between these diagnoses. A prompt diagnosis is essential as the patient may require urgent surgical intervention
Testicular torsion refers to twisting of the spermatic cord, causing ischaemia of the testicle.
Testicular torsion results from inadequate fixation of the testis to the tunica vaginalis producing ischemia from reduced arterial inflow and venous outflow obstruction.
The prevalence of testicular torsion in adult patients hospitalized with acute scrotal pain is approximately 25 to 50 percent
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
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A presentation on terpenoids final 1488237641076
1. A PRESENTATION ON TERPENOIDS
Presented by
Ayesha Choudhury
m.Pharm 2nd sem
Deptt. Of pharm. sciences
2. INTRODUCTION
TERPENOIDS:
Terpenoids are defined as the hydrocarbons of plant origin having the general formula -(C5H8)n where n is the
number of linked isoprene (2-methyl-1,3-butadiene) units (isoprenoids). Terpenoids can be thought of as modified
terpenes. However the term terpene is misnomer and restricted to the hydrocarbons C10H16 as the suffix “ene”
signifies unsaturated hydrocarbons and so the term terpene is in appropriate to compound having aldehyde, ketone &
alcohol functionality i.e., terpenoids.
OCCURANCE:
Terpenoids form a group of compounds, the majority of which occurs in plant kingdom.
• Mono and sesquiterpenoids are the essential oils obtained from sap and tissues of plants and trees.
• Di and Tri Terpenoids are obtained from plant and tree gums and resins.
• Tetra terpenoids form a group of compounds known as carotenoids.
• Polyterpenoid : Rubber .
3. CLASSIFICATION OF TERPENOIDS
Most natural terpenoids hydrocarbon have the general formula (C5H8)n. They can be classified on the basis of value of
‘n’ i.e., isoprene unit or number of carbon atoms present in the structure.
Each class can be further subdivided into subclasses according to the number of rings present in the structure:
i) Acyclic Terpenoids: They contain open structure e.g., citral
ii) Monocyclic Terpenoids: They contain one ring in the structure e.g., menthol
iii) Bicyclic Terpenoids: They contain two rings in the structure. E.g., camphor.
iv) Tricyclic Terpenoids: They contain three rings in the structure. E.g., abietic acid
v) Tetracyclic Terpenoids: contain four rings in the structure. E.g., gibberellic acid
4. ISOPRENE RULE
In 1887, Wallach pointed out the isoprene rule from the following facts:
• The empirical formula of almost all naturally occurring terpenoids is -(C5H8)n
• Thermal decomposition of almost all terpenoids gives isoprene as one of the products.
• Confirmed by:
2C5H8 heat , 280⁰c C10H16
nC5H8 polymerization -(C5H8)n
Special isoprene rule:
• Proposed by Ingold in 1925
• Isoprene units in terpenoids are linked in “ head to tail” fashion.
• The branched end (head) is isopropyl and other end being the (tail)
6. The above four methods are used for isolating the essential oil containing mixture of terpenoids.
The next step is the separation of terpenoids from essential oil: it involves two methods
Chemical methods: involves treating the essential oil with some chemical agents like nitrosyl
chloride, phthalic anhydride etc.
Physical methods: involves fractional distillation method and gas chromatography(modern
method)
7. STRUCTURE ELUCIDATION OF SOME TERPENOIDS
General methods:
Molecular formula
Nature of oxygen atom present: generally terpenoids have alcoholic, carbonyl or carboxylic acid as oxygen function.
E.g.,
Unsaturation:
Dehydrogenation:
Oxidative degradation
Spectroscopic studies.
8. STRUCTURAL ELUCIDATION OF MENTHOL
Chemical formula: C10H20O, m.p. 34 °C, b.p. 213 °C
Menthol is an optically active compound & only the levo (-)form occurs naturally in
peppermint oil obtained from Mentha piperita.
It is a saturated compound under monocyclic monoterpenoids. MENTHOL
Molecular formula of menthol was determined as C10H20O. On treatment with phosphorus pentachloride and
phosphorus pentoxide menthol gave a chloride C10H19Cl and a hydrocarbon C10H18 respectively, inferring
that it is an alcohol.
9. Menthol was oxidized by chromic acid to a ketone, Menthone to
prove that menthol contained a secondary hydroxyl group.
Menthol was converted to p-cymene identified as
1-methyl-4-isopropylbenzene, which was also obtained by the
dehydrogenation of pulegone whose structure was established as
p-menth-4-(8)-en-3-one by chemical methods and confirmed by its
synthesis Therefore menthol must possess the same skeleton as
pulegone.
Pulegone on reduction yielded menthone, which on further reduction
gave Menthol. Correlation of pulegone with menthol proved the
structure of menthol
10. Stereochemistry:
Menthol has three asymmetric centers namely
C1, C3 and C4. In view of the three chiral centers,
eight optically active forms are possible and all
the eight enantiomers are known.
Four isomers are shown in Figure.
Finally the structure of menthol was proved
by its synthesis:
11. STRUCTURAL ELUCIDATION OF CAMPHOR
Camphor is solid ketone obtained from volatile oil of Cinnamomum camphora under the family Lauraceae,
mp: 180⁰c, bp: 204 ⁰c. optically active.
The molecular formula is C10H16O (bicyclic monoterpenoid)
Nature of oxygen atom: it is ketone as it forms oxime with NH2OH & phenyl hydrazine with
phenylhydrazine
Presence of bicyclic ring system: the parent hydrocarbon of camphor has molecular formula C10H18, which
corresponds to the molecular formula of bicyclic compounds(CnH2n-2)
Presence of six membered ring: when distilled with ZnCl2/P2O5 it forms p-cymene.
12. Presence of –COCH2- group in camphor is confirmed by its formation to isonitroso derivative with amyl nitrile &
HCl.
Camphor on oxidation with HNO3 gives camphoric acid & camphoronic acid .
Camphoronic acid is saturated tricarboxylic acid & on distillation at atm pressure gives:
Bredt suggested that camphoronic acid is 2,3-dimethyl-1,2,3-butanetricarboxylic acid, hence having 3 –CH3 group so
camphor must have 3-methyl group.
13. On the basis of the formula of camphoric acid “C10H16O4” it was found that camphoric acid is a
cyclo pentane derivative and the structure was proposed as:
Bredt proposed the following reaction to show the relationship between camphor, camphoric acid
& camphoronic acid and established the structure of camphor.
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