Alkaloids

this ppt is about alkaloids. it talks first introduction then classifications then we talk about the properties , applications ,then lastly we talked about the extraction. alkaloids are very important our daily life. alkaloid is simply means water soluble base.is detected by either by preciptants or colour reagent ,Alkaloids are often divided into the following major groups:
True alkaloids
pseudo alkaloids
Proto alkaloids
False alkaloids.

1. Alkaloids Name: SIDIK HASSAN 皇帝 Student No .:911703817007

2. 1.Introduction 2.Classifications 3.Properties of alkaloids 4.Applications 5. Extraction C ontents

3. 1.In troduction The term alkaloid is applied to nitrogen containing molecules belonging to one of the largest and most diverse families of naturally occurring compounds. The nitrogen usually is part of heterocyclic system . These compounds are grouped together by the presence of nitrogen atom in their structure

4. 1.In troduction The term alkaloid was coined in 1819 by the pharmacist W. Meisner and meant simply , alkali like (Middle English alcaly , from Medeval Latin alkali, from Arabic alqaliy = ashes of stalwart, from qualey , to fry). Alkaloid derives from the word alkaline which means a water soluble base

5. 1.In troduction The present of alkaloids is detected either by precipitants or colour reagents. The more important precipitant are Mayer , Wagner , Dragendorff and Hager . The color reagents mostly consist of dehydrating, oxidizing or a combination of two.

6. 1.In troduction

7. 1.In troduction Distribution in Plant : All Parts e.g. Datura . Barks e.g. Cinchona Seeds e.g. Nux vomica Roots e.g. Aconite Fruits e.g. Black pepper Leaves e.g. Tobacco Latex e.g. Opium

8. 1.Introduction 2.Classifications 3.Properties of alkaloids 4.Applications 5. Extraction C ontents

9. 2.Classifications of alkaloids Alkaloids are often divided into the following major groups: True alkaloids pseudo alkaloids Proto alkaloids False alkaloids

10. 2.Classifications of alkaloids Many classification systems are possible for alkaloids Due to variety of sources Basic chemical structure, Pharmacological action

11. 2.Classifications of alkaloids 1. Tropane 2. Quinoline 3 . Isoquinoline 4 . Indole 5. purine

12. 2.Classifications of alkaloids 6 . Pyrrole & Pyrrolidine Nicotine 7 . Pyridine & Piperidine Ricinine 8.Phenanthrene Morphine 9 . Imidazole Pilocarpine 10.Steroidal Connesine

13. 1.Introduction 2.Classifications 3.Properties of alkaloids 4.Applications 5. Extraction C ontents

14. 3.Properties of alkaloids 3.1 physical properties condition Most alkaloids are crystalline solids. Few alkaloids are amorphous solids e.g. emetine. Some are liquids that are either: Volatile e.g. nicotine and coniine, or Non-volatile e.g. pilocarpine and hyoscine

15. 3.Properties of alkaloids II- Color : The majority of alkaloids are colorless but some are colored e.g.: Colchicine and berberine are yellow. Canadine is orange. The salts of sanguinarine are copper-red.

16. 3. Properties of alkaloid III- Solubility: Both alkaloidal bases and their salts are soluble in alcohol. Generally, the bases are soluble in organic solvents and insoluble in water Exceptions: Bases soluble in water: caffeine, ephedrine, codeine, colchicine, pilocarpine and quaternary ammonium bases. Bases insoluble or sparingly soluble in certain organic solvents: morphine in ether, theobromine and theophylline in benzene. Salts are usually soluble in water and, insoluble or sparingly soluble in organic solvents. Exceptions: Salts insoluble in water: quinine monosulphate . Salts soluble in organic solvents: lobeline and apoatropine hydrochlorides are soluble in chloroform

17. 3.Properties of akaloids 3.2 chemical properties Most alkaloids contain Oxygen and are solid in nature e.g. Atropine Some alkaloids are free from Oxygen and are mostly liquids e.g. Nicotine, Coniine. Alkaloids are decomposed by heat, except Strychnine and caffeine ( sublimable ). they react with acids to form salt formation Saturated hexacyclic amines is more basic than aromatic amines .

18. 1.Introduction 2.Classifications of Alkaloids 3.Properties of alkaloids 4.Applications 5.Extraction C ontents

19. 4. Applications 4.1 Functions in plants They may act as protective against insects an herbivores due to their bitterness and toxicity. They are, in certain cases, the final products of detoxification (waste products). Source of nitrogen in case of nitrogen deficiency. They, sometimes, act as growth regulators in certain metabolic systems. They may be utilized as a source of energy in case of deficiency in carbon dioxide assimilation.

20. 4. Applications 4.2 in medicine Atropine: eyes, heart, secrations quinine: treat malaria Reserpine: Hypertesion caffeine: CNS stimulant nicotine : Enhances concentration, learning and memory. Morphine : pain medication

21. 1.Introduction 2.Classifications of Alkaloids 3.Properties of alkaloids 4.Applications 5. Extraction C ontents

22. 5.Extraction Because of the structural diversity of alkaloids, there is no single method of their extraction from natural raw materials. Most methods exploit the property of most alkaloids to be soluble in organic solvents but not in water, and the opposite tendency of their salts . Most plants contain several alkaloids. Their mixture is extracted first and then individual alkaloids are separated . Plants are thoroughly ground before extraction. Most alkaloids are present in the raw plants in the form of salts of organic acids. The extracted alkaloids may remain salts or change into bases .

23. 5.Extraction Base extraction is achieved by processing the raw material with alkaline solutions and extracting the alkaloid bases with organic solvents, such as 1,2-dichloroethane, chloroform, diethyl ether or benzene. Then, the impurities are dissolved by weak acids; this converts alkaloid bases into salts that are washed away with water. If necessary, an aqueous solution of alkaloid salts is again made alkaline and treated with an organic solvent. The process is repeated until the desired purity is achieved

24. 5.Extraction In the acidic extraction , the raw plant material is processed by a weak acidic solution (e.g., acetic acid in water, ethanol, or methanol). A base is then added to convert alkaloids to basic forms that are extracted with organic solvent (if the extraction was performed with alcohol, it is removed first, and the remainder is dissolved in water). The solution is purified as described above . Alkaloids are separated from their mixture using their different solubility in certain solvents and different reactivity with certain reagents or by distillation .

25. References Natural products chemistry sources, seprations and structures (Raymond Cooper George Nicola) Introduction to natural product chemistry

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