History of Alkaloids:
- The French apothecary Derosne probably isolated the alkaloid afterwards known as narcotine in 1803 and the Hanoverian apothecary Sertürner further investigated opium and isolated morphine (1806, 1816).
- Isolation of other alkaloids, particularly by Pelletier and Caventou, rapidly followed; strychnine (1817), emetine (1817), brucine (1819), piperine (1819), caffeine (1819), quinine (1820), colchicine (1820) and coniine (1826).
- Coniine was the first alkaloid to have its structure established (Schiff, 1870) and to be synthesized (Ladenburg, 1889), but for others, such as colchicine, it was well over a century before the structures were finally elucidated.
- Modern methods and instrumentation have greatly facilitated these investigations, chemists during the first quarter of the last century would now be sufficient, several thousand times over, for a complete structure analysis.
- In the second half of the twentieth century alkaloids featured strongly in the search for plant drugs with anticancer activity.
- There is much current interest in other alkaloids having anticancer properties as well as those exhibiting antiaging and antiviral possibilities.
•Alkaloids have complex molecular
structure.
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•Steps for structural elucidations.1.Determine the structure of pure Alkaloids as its molecular formula and optical rotatory power.2. Unsaturation:- Addition of Br - Addition of halogen acids - Hydroxylation with dil. alkaline permanganate.
- 3. Cleaved into simple fragments by hydrolysis with water, acids or alkalies & fragments so obtained examined separately. i.e. piperine on hydrolysis gives piperidine & piperic acid both attached through acid – amide linkage.4. Ascertaining the functional nature of Oxygen & Nitrogen atoms.
