S R M COLLEGE OF PHARMACY PHARM D I YEAR REMEDIAL BIOLOGY SUBJECT CODE PDG 106

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1 S R M COLLEGE OF PHARMACY PHARM D I YEAR REMEDIAL BIOLOGY SUBJECT CODE PDG 106

2 UNIT I Introduction to Pharmacognosy

3 Naturally occurring substances having a medicinal action: Surgical dressings prepared from natural fibres Flavourings and suspending agents Disintegrants Filtering and support media Other associated fields: Poisonous and hallucinogenic plants Raw materials for production of oral contraceptives Allergens Herbicides and insecticides

4 Pharmacognosy is related to: Botany Ethnobotany Marine biology Microbiology Herbal medicine Chemistry (phytochemistry) Pharmacology Pharmaceutics

5 Skills & techniques valuable elsewhere: Analysis of other commodoties Foods, spices, gums, perfumes, fabrics, cosmetics Used by Public analysts, forensic sciences, quality control scientists Role in pure sciences Botany, plant taxonomy, phytochemistry Botanists and chemists looking at: Chemical plant taxonomy, genetic/enzymatic studies involving 2 y metabolites Artificial and tissue culture Effects of chemicals on plant metabolites Induction of abnormal syntheses Bioassay guided isolation techniques

6 Vegetable drugs can be arranged for study: Alphabetical Taxonomic** botanical classification Morphological Organised drugs: leaves, flowers, fruit, seeds etc Unorganised drugs: extracts, gums, resins, oils etc Pharmacological/therapeutic* Increasingly used with screening Constituents of one drug may fall into several groups Chemical/biogenetic Constituents or biosynthetic pathways

7 CLASS Angiospermae (Angiosperms) Plants which produce flowers Gymnospermae (Gymnosperms) Plants which don't produce flowers SUBCLASS Dicotyledonae (Dicotyledons, Dicots) Plants with two seed leaves Monocotyledonae (Monocotyledons, Monocots) Plants with one seed leaf SUPERORDER ORDER FAMILY SUBFAMILY A group of related Plant Families, classified in the order in which they are thought to have developed their differences from a common ancestor. There are six Superorders in the Dicotyledonae (Magnoliidae, Hamamelidae, Caryophyllidae, Dilleniidae, Rosidae, Asteridae), and four Superorders in the Monocotyledonae (Alismatidae, Commelinidae, Arecidae, Liliidae) The names of the Superorders end in -idae Each Superorder is further divided into several Orders. The names of the Orders end in -ales Each Order is divided into Families. These are plants with many botanical features in common, and is the highest classification normally used. At this level, the similarity between plants is often easily recognisable by the layman. Modern botanical classification assigns a type plant to each Family, which has the particular characteristics which separate this group of plants from others, and names the Family after this plant. The number of Plant Families varies according to the botanist whose classification you follow. Some botanists recognise only 150 or so families, preferring to classify other similar plants as sub-families, while others recognise nearly 500 plant families. A widely-accepted system is that devised by Cronquist in 1968, which is only slightly revised today. The names of the Families end in -aceae The Family may be further divided into a number of sub-families, which group together plants within the Family that have some significant botanical differences. The names of the Subfamilies end in -oideae

8 TRIBE SUBTRIBE GENUS A further division of plants within a Family, based on smaller botanical differences, but still usually comprising many different plants. The names of the Tribes end in -eae A further division, based on even smaller botanical differences, often only recognisable to botanists. The names of the Subtribes end in -inae This is the part of the plant name that is most familiar, the normal name that you give a plant - Papaver (Poppy), Aquilegia (Columbine), and so on. The plants in a Genus are often easily recognisable as belonging to the same group. The name of the Genus should be written with a capital letter. SPECIES This is the level that defines an individual plant. Often, the name will describe some aspect of the plant - the colour of the flowers, size or shape of the leaves, or it may be named after the place where it was found. Together, the Genus and species name refer to only one plant, and they are used to identify that particular plant. Sometimes, the species is further divided into sub-species that contain plants not quite so distinct that they are classified as Varieties. The name of the species should be written after the Genus name, in small letters, with no capital letter. VARIETY FORM CULTIVAR A Variety is a plant that is only slightly different from the species plant, but the differences are not so insignificant as the differences in a form. The Latin is varietas, which is usually abbreviated to var. The name follows the Genus and species name, with var. before the individual variety name. A form is a plant within a species that has minor botanical differences, such as the colour of flower or shape of the leaves. The name follows the Genus and species name, with form (or f.) before the individual variety name. A Cultivar is a cultivated variety, a particular plant that has arisen either naturally or through deliberate hybridisation, and can be reproduced (vegetatively or by seed) to produce more of the same plant. The name follows the Genus and species name. It is written in the language of the person who described it, and should not be translated. It is either written in single quotation marks or has cv. written in front of the name.

9 Example Linnaeus ( ), Swedish biologist Division Angiospermae Class Dicotyledoneae Subclass Sympetalae Order Tubiflorae Suborder Verbenineae FamilyLabiatae (Lamiaceae) Subfamily Stachydoideae Tribe Satureieae Genus Mentha Species Mentha piperita Linnaeus (peppermint) Varieties Mentha piperita var. officinalis Sole (White Peppermint); Mentha piperita var. vulgaris Sole (Black Peppermint)

10 Contribution of plants to medicine and pharmacy 18 th century drugs plant based 19 th century a range of drugs was isolated: 1805 morphine 1817 emetine 1819 strychnine 1820 quinine Famous plants/plant drugs?

11 Quinine Cinchona bark, South American tree Used by Incas; dried bark ground and mixed with wine First used in Rome in 1631 Extracted 1820 Large scale use 1850 Chemical synthesis 1944 Actual tree remains the most economic source

12 Belladonna > atropine Anticholinergic syndrome: Hot as hell Blind as a bat Red as a beet Dry as a bone Mad as a hatter

13 Physostigma venosum Calabar bean

14 Why do we need plants? 1. Source of drug molecules Most drugs can be synthesised Still more economical to use the plant Papaver opium > morphine, codeine (strong medicinal pain) Ergot fungus > ergotamine (headache), ergometrine (direct action on uterine muscle)

15 2. Source of complex molecules that can be modified to medicinal compounds Examples: Droscera yam: molecule > steroids Soya: saponins > steroids

16 3. Source of toxic molecules To study the way the body responds to their pharmacological use Investigating pharmacological mechanisms picrotoxin nerve conduction

4. Source of compounds to use as templates for

Once structure worked out wanted to improve it.

Diacetylmorphine (heroin): OH group -> O-O-diacetyl.

Codeine: Methylate hydroxyl phenolic; O-Me.

17 4. Source of compounds to use as templates for designing new drugs Morphine: No better painkiller. Once structure worked out wanted to improve it. What is required? Diacetylmorphine (heroin): OH group -> O-O-diacetyl. Still addictive? Codeine: Methylate hydroxyl phenolic; O-Me. 1/5 analgesic capacity of morphine, useful to suppress cough reflex Dihydromorphinone: Reduced =, oxidised 2y alc. Potential analgesic.

18 Future 80% world population rely on natural remedies Westernization of societies ( traditional knowledge) Extermination of species» conservation, retain gene pools Natural resources exhausted» cultivation, artificial propogation

19 Conclusion Natural products very important to medicine Exist in range of structures that one wouldn t think of synthesizing Can act as templates for new drug development Untapped reservoir of new compounds

stomata Land plants evolved from green algae.

stomata Land plants evolved from green algae. SECTION 20.1 ORIGINS OF PLANT LIFE Study Guide KEY CONCEPT Plant life began in the water and became adapted to land. VOCABULARY plant vascular system seed cuticle lignin stomata pollen grain Land plants