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11 Cards in this Set
- Front
- Back
Define Pharmacognosy. |
Branch of bioscience, which treats in detail,
medicinal and related products of crude or primary type, obtained from natural sources such as plants, animals and minerals |
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What are crude drugs?
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Drugs obtained from natural sources -- in their unprocessed forms.
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Etiology of Pharmacognosy.
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Pharmacognosy = Pharmakon + Gignosco
– Pharmakon „a drug‟ – gignosco „to acquire knowledge of‟ |
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Era of Pure compounds?
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1803 - Pure phytoconstituents were
isolated from the plant extracts using various separation and isolation techniques. • Morphine from opium poppy (Papaver somniferum, Papaveraceae), which was first identified by FW Serturner of Germany ) in 1804 and chemically characterized in 1817 as an alkaloid. The full structure was established in 1923, by JM Gulland and R Robinson, inManchester. • Strychnine (1817) - from Strychnos spp.(Loganiaceae), was used as a tonic and stimulant • Quinine - from cinchona bark (Cinchona succirubra and others), was first isolated by Pierre Joseph Pelletier and Joseph Bienaime Caventou of France in 1820; the structure was elucidated in the 1880s by various laboratories. • Caffeine (1821) - from the coffee shrub (Coffea arabica and C. canephora, Rubiaceae); its structure was elucidated in 1882. Stimulant. • Nicotine (1828) - Nicotiana tabacum. CNS Stimulant. • Atropine (1833) - from belladonna (Atropa belladonna, Solanaceae), was used at the time for asthma. • Cocaine (1855) • Salicin, from willow bark (Salix spp., Salicaceae), was first isolated by Johannes Buchner in Germany |
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Sources of Information?
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• Early Arabic and European records. • Classical Arabic, Greek and Roman records. • Classical Chinese records. • Other Asian traditional medicine. • The European Middle Ages and Arabia. • Printed reports in European tradition. |
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Discoveries in Pharmacognostic research in 19th and 20th centuries.
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• In the 19 th century, the chemical structures of many of the isolated compounds were determined. • In the 20 th century, the discovery of important drugs from the animal kingdom, particularly hormones and vitamins. • Microorganisms also became a very important source of drugs. |
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Cognosy is multidisciplinary. Explain.
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1. Botany & Zoology which includes history [biological name, family],
distribution, cultivation, collection, study of morphological & microscopic characteristics, processing of the crude drug and its traditional uses. 2. Pharmacology. 3. Phytochemistry. PHARMACOGNOSTIC STUDY IS RELATED TO: – Botany – Ethnobotany – Marine biology – Microbiology – Chemistry (phytochemistry) – Pharmacology – Pharmaceutics |
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Value of natural products..?
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Compounds from natural sources play three significant roles in modern
medicine: 1. They provide a number of extremely useful drugs that are difficult, if not impossible, to produce commercially by synthetic means [eg. Taxus brevifolia] Taxol. 2. Natural sources also supply basic compounds that may be modified slightly to render them more effective or less toxic [semi-synthetic drugs]. [eg. Artemisia annua-Artemisinin (lactone group)-Artemether (acetal group)]. 3. Their utility as prototypes or models for synthetic drugs possessing physiologic activities similar to the originals. [Example - Camphor]. |
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Applications of Pharmacognosy.
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APPLICATIONS OF PHARMACOGNOSTICAL SKILLS
1. Analysis of other commodities: • Foods, spices, gums, perfumes, fabrics & cosmetics. 2. Used by: • Forensic sciences & quality-control scientists. 3. Role in pure sciences: • Botany, plant taxonomy & phytochemistry. 4. Botanists and chemists working on: • plant taxonomy & genetic/enzymatic studies. • Plant tissue culture. • Effects of chemicals on plant metabolites. 5. Bioassay-guided fractionation and isolation techniques. -> Meaning step-by-step separation of extracted components based on differences in their physicochemical properties, and assessing the biological activity, followed by next round of separation and assaying. |
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Types of Drugs derived from natural source
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TYPES OF DRUGS DERIVED FROM PLANTS
1. Herbal drugs, derived from specific parts of a medicinal plant Eg. 2. Pure Isolated compounds Eg. 3. Nutraceuticals or “functional foods” Eg. Garlic, ginger, turmeric and many other herbs and spices l anthocyanin-orflavonoid-containingplantssuch as bilberries, cocoa and red wine l carotenoid-containing plants such as tomatoes, carrots and many other vegetables. |
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Scope of Cognosy |
# The pharmacognosist would serve in various aspects as follows:
->Academics: Teaching in colleges, universities, museums and botanical gardens. ->Private industry: Pharmaceutical companies, consumer products testing laboratories and private commercial testing laboratories, the herbal product industries, the cosmetic and perfume industries, etc. ->Government: Placement in federal agencies, such as the Drug Enforcement Agency, the Food and Drug Admin- istration, the U.S. Department of Agriculture, Medicinal plant research laboratories, state agencies like forensic laboratories, environmental laboratories, etc. #Undoubtedly, the plant kingdom still holds large number of species with medicinal value which have yet to be discov- ered. Lots of plants were screened for their pharmacological values like, hypoglycaemic, hepatoprotective, hypotensive, antiinflammatory, antifertility, etc. pharmacognosists with a multidisciplinary background are able to make valuable contributions in the field of phytomedicines. |