Introduction
History of Pharmacognosy
The greek physician Dioscorides (40 – 80 A.D) described about medicinal plants like Opium, belladonna, colchium and ergot. Galen ( 131 – 200 A.D) known as first pharmacist described the different methods of preparation containing active constituents of crude drugs. The branch dealing with extraction of plants and animal drugs is still known as Galenical pharmacy. The french apothecary N. Lemary (1645 – 1715) reported the importance of extraction method and alcohol to be used as an ideal solvent. In 1806 the german chemist “serturner” isolated morphine from opium. In 1811 thhe portugese chemist “Gomeriz” isolated cinchonine from cinchona bark.The french chemist pelletier and caventou isolated strychnine and brucine from nux vomica seeds.
Chemical constituents
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Scientist Name
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Quinine
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Pelletier (1820)
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Veratramine
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Meissener (1820)
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Nicotine
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Posselt and Reiman (1828)
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Amygdalin
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(1830)
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Pilocarpine
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Hardy and Gerrod (1875)
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Ephedrine
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Nagai (1887)
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Stass and Otto in 1852 developed a new process of extraction for alkaloids. The developments in the field of botany during 19th century had a direct effect on pharmacognosy. The great swedish biologist linnaeus (1707- 1778) classified the plants and introduced the binamical system of plants. Plant classification was further developed by Bentham and Hooker (1862 – 1883), Eichler (1883), Engler and Prandtle (1887 – 1889).
Scope of Pharmacy:
Crude drugs of plant origin can be obtained from
- Entire plants. Eg- Ergot,Ephedra
- Parts of plants. Eg – Senna leaves,Nux vomica seeds
- Exudation of plants. Eg- Gums,resins.
- Processing of plants. Eg- Opium, black catechu.
Drugs obtained from animals
- Entire animals Ex: Cantharides
- Glandular secretions Ex: Thyroid, Insulin
- Extraction process Ex: Liver extract
Drugs obtained from Minerals
Number of drugs Like : Chalk, diatamite, kaolin…etc