1. BIOSYNTHETIC PATHWAYS- MEDICINALLY IMPORTANT COMPONDS

2. I NTRODUCTION : M ETABOLISM The complex of physical and chemical processes occurring within a living cell or organism that are necessary for the maintenance of life. In metabolism some substances are broken down to yield energy for vital processes while other substances, necessary for life, are synthesized.

3. G LUCOSE CATABOLISM Glucose will be oxidized by all tissues to synthesis ATP. The first pathway which begins the complete oxidation of glucose is called Glycolysis. This pathway cleaves the six carbon glucose molecule (C 6 H 12 O 6 ) into two molecules of the three carbon compound Pyruvate (C 3 H 3 O 3 - ). This oxidation is coupled to the net production of two molecules of ATP/glucose.

4. R ESPIRATION :

5. Glucose Glucose-6-P Pyruvate Hexokinase Pentose Phosphate Shunt glycolysis C ARBOHYDRATES Glc-1- phosphate Glycogen Cytosol - anaerobic

6. Pyruvate Cytosol Acetyl CoA Mitochondria (Aerobic) Krebs cycle Reducing equivalents Oxidative Phosphorylation (ATP) AMINO ACIDS FATTY ACIDS

7. G LYCOLYSIS : Provide ATP energy Generate intermediates for other pathways Hexose monophosphate pathway Glycogen synthesis Pyruvate dehydrogenase Fatty acid synthesis Krebs’ Cycle

10. Balance sheet for ~P bonds of ATP:  2 ATP expended  4 ATP produced (2 from each of two 3C fragments from glucose)  Net production of 2 ~P bonds of ATP per glucose. Glycolysis - total pathway, omitting H + : glucose + 2 NAD + + 2 ADP + 2 P i  2 pyruvate + 2 NADH + 2 ATP In aerobic organisms:  pyruvate produced in Glycolysis is oxidized to CO 2 via Krebs Cycle  NADH produced in Glycolysis & Krebs Cycle is reoxidized via the respiratory chain, with production of much additional ATP.

11. A NAEROBIC ORGANISMS LACK A RESPIRATORY CHAIN Some anaerobic organisms metabolize pyruvate to ethanol, which is excreted as a waste product. NADH is converted to NAD + in the reaction catalyzed by Alcohol Dehydrogenase.

12. C ITRIC A CID C YCLE Phase Two of oxidation of Glucose 1953 Nobel Prize in Medicine and Physiology

13. T HE F ATE OF P YRUVATE AND THE TCA C YCLE Under aerobic conditions pyruvate is decarboxylated to acetate. Acetate is oxidized further in the citric acid cycle. A series of oxidation reduction reactions results in the formation of CO 2 from acetate and the transfer of electrons producing NADH and FADH 2. The reducing potential (NADH and FADH 2 ) harvested from the TCA cycle is used to drive the phosphorylation of ADP → ATP

14. The decarboxylation of pyruvate, and the oxidation of acetate takes place in the mitochondrial matrix. ATP synthesis takes place in the inner membrane.

15. K REBS CYCLE The yield for every turn of the cycle is 2CO 2, 3NADHs, 1FADH 2, and 1GTP.

16. M EDICINALLY I MPORTANT C OMPOUNDS : Plants have been the source of medicines for thousands of years. Important medicinal plants used in various systems of medicine, are widely distributed in the world and are of high commercial and economical importance.

17. C OLLECTION OF MEDICINAL COMPOUNDS Drugs may be collected from wild or cultivated plants. It is known that the active constituents of medicinal plants are affected by many factors and may vary during the course of plant growth. Proper time of collection is very important to obtain a drug of a good quality. Ex: Alkaloids,Terpenoids, Citric acid, Cocaine,Nicotine etc.

18. A LKALOIDS Medicinally the most important Generally, taste bitter (have alkaline, or basic chemical properties) a group of naturally occurring chemical compounds which mostly contain basic nitrogen atoms. "True alkaloids", which contain nitrogen in the heterocycle and originate from amino acids

19. E XAMPLES OF ALKALOIDS o Morphine 1 st to be isolated Analgesic, derived from opium poppies o Cocaine From the coca plant An anesthetic, It can use to alleviate hunger, pain and it contains vital nutrients. o Caffeine Stimulant in coffee, tea Lethal to insects, fungi

20. Nicotine is an alkaloid found in the nightshade family of plants ( Solanaceae ) that constitutes approximately 0.6–3.0% of the dry weight of tobacco Highly toxic, derived from tobacco

21. Atropine well-known pupil dialator cardiac stimulant A cardiac stimulant is a substance which acts as a stimulant of the heart

22. TERPENOIDS All are built of isoprenes (C 5 H 8 ) Isoprene is exuded by plants in large quantities

23. FLAVONOIDS Water-soluble pigments, found in red wine, grape juice Intensely studied for cholesterol-reduction

24. LIGNINS Add strength to cell wall Waterproof Aspirin Greeks and native Americans used bark of willows (Genus: Salix) as analgesic