![Prepared by
Dr. N.GOPINATHAN
ASSISTANT PROFESSOR
DEPARTMENT OF PHARMACEUTICAL
CHEMISTRY
FACULTY OF PHARMACY
SRIHER [DU]
CHENNAI-116
TAMILNADU](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Recommended
More Related Content
What's hot
What's hot (20)
Similar to Alkaloids
Similar to Alkaloids (20)
More from gopinathannsriramachandraeduin
More from gopinathannsriramachandraeduin (20)
Recently uploaded
Recently uploaded (20)
Alkaloids
- 1. Alkaloids
- 2. Prepared by Dr. N.GOPINATHAN ASSISTANT PROFESSOR DEPARTMENT OF PHARMACEUTICAL CHEMISTRY FACULTY OF PHARMACY SRIHER [DU] CHENNAI-116 TAMILNADU
- 3. Introduction • Alkaloid the term is coined by pharmacist W. Meissner in 1819 for the basic, nitrogen containing compounds of plant origin. • The basicity is due to presence of nitrogen inside the ring. • It is physiologically active basic compounds of plant origin, in which at least one nitrogen atom forms part of a cyclic system.
- 4. • The above definition is not fully satisfactory because some compounds although alkaloid do not confine to this definition. • Adrenalin and ephedrine have nitrogen atom in the side chain. Ephedrine
- 5. • Other compounds although not alkaloids confined to this definition . • Only 10-15 % found in all vascular region. • It is rarely found in lower plants like algae, fungi [ ergot alkaloid ].
- 7. History
- 8. Heterocyclic physiologically active nitrogen but not regarded as alkaloids Thiamine Purine caffeine theobromine xanthine
- 9. It exist as salt of plant acid such as acetic acid, oxalic acid, citric acid, malic, lactic, tartaric , tannic and aconiticacid.
- 10. Tartaric acid Aconitic acid
- 11. Cinchona alkaloid with quininic acid , and opium alkaoid with meconic acid.
- 14. Distribution of alkaloid in plant
- 15. Other sources
- 16. Occurence
- 17. Occur in free form narceine and nicotine.
- 18. As glycoside – Solanum and veratrum.
- 19. As amides – Piperine
- 20. Esters- Tropine and cocaine.
- 21. Colchinine is regarded as alkaloid although it is not heterocyclic.
- 22. Thiamine is heterocyclic nitrogenous base because it is universally distributed in living matter so not included in alkaloid.
- 23. It is found in dicotyledons like • Apocynaceae, • Papaveraceae, • Papilionaceae, • Ranunculaceae, • Rubiaceae, • Rutacea, • Solanaceae.
- 24. The purpose of existence of alkaloid in plant • It is regarded as bye product of plant metabolism. • It act as reservoir of protein synthesis. • It act as protective substance against the animal or insect attack. • It function as plant stimulant like growth, metabolism and reproduction. • As detoxifying agent by methylation, condensing and cyclize the compounds.
- 25. Nomenclature • Due to complex structure and some historical reason there was no systematic nomenclature of alkaloids. • It is named according to the plants from which they are obtained. • Papaverine – papaver somniferum. • Berberine – berberis vulgaris.L
- 26. Few named after their physiological action such as • Morphine [ German morphin- God of dreams ] • Narcotine [ Greek narkov – be numb] • Emetine [ Greek emetikos – to vomit ]
- 27. Some of it has been named after their discoveries pelletierine group • P.J.Pelletier
- 28. Minor alkaloids named has been derived by adding one prefix or suffix to the name of principal alkaloid • Cinchona series
- 29. Nomenclature • Related bases have been named by transposition as narcotine, cotarine and tarconine. • Prefix such as epi, iso,neo,pseudo etc.. Greek letters have been used to designate isomeric or slightly modified structure. • The prefix nor denotes the structure which does not have a methyl group attached to the nitrogen atom.
- 30. Classification
- 34. Taxonomic • It is done according to family. • Alkaloids are described as solanaceous or papilionaceous without reference to chemical type. • Both the families contain alkaloid of several type. • Solanaxeae -tropane,pyridine steroidal • Papilionaceae-Quinolizidine & pyrrolizidine. • Disadvantage of the system is obvious.
- 35. Pharmacological classification • It is based on their use or physiological activity. • Analgesic, cardio active alkaloids. • Alkaloids within a group frequently have chemical similarities.
- 36. Biosynthetic classification • It is more fundamental method than chemical classification. • It depends on the type of precursor or building block of compounds used by plants to synthesis complex structure. • Hundreds of indole alkaoids are derived from the amino acid tryptophan and mevalonic acid as ergot or cinchona alkaloid.
- 37. • Similarly morphine, papaverine , narcotine tubocurarine and colchinine may be listed as phenyl alanine tyrosine derived base. • The disadvantage of this method is precursor which is not always apparent.
- 39. 1. Phenylethylamine alkaloidEphedrine, adrenaline and nor adrenaline
- 44. 6.Tropane alkaloid Atropine Cocaine
- 46. 8.Isoquinoline Alkaloid papaverine narcotine emetine
- 48. 10.Indole Alkaloid ergotamine, Reserpine Strychnine Brucine
- 51. Isolation • Isolation and purification of an alkaloid from a plant is always not a simple process. • Plants may contain complex several alkaloids. Their isolation of an pure alkaloid may become an extremely laborious procedure. • First of all the presence of an alkaloids in a plant is ascertained by employing various reagent called alkaloidal reagent
- 53. • Chloroplatinic acid H2PtCl6, chloroauric acid HAuCl4, Phosphotringstic and molybdic acid are useful precipitating agent. • The precipitate have characteristic colours and are used for the detection of alkaloids in very small amount. • After detection seperation of alkaloids from plant. • Final step is purification. • For isolation of small quantity of an alkaloid chromatography is most satisfactory.
- 54. Other colouring reagents usedto detect alkaloids are • Formaldehyde [ Marquis reagent] • Nitric acid [ Erdmann’s reagent ] • Molybdic acid [ Frende’s reagent ]