PYRIDINE - PIPERIDINE ALKALOIDS

PYRIDINE - PIPERIDINE ALKALOIDS
Dr. Saad Ali Ihsan
Ph.D. Pharmacognosy & Medicinal Plants

On reduction, the tertiary base, pyridine, is converted into the secondary base, piperidine .These two nuclei form the basis of this group, which is sometirnel divided into three subgroups :

(I) Derivatives of piperidine ,including lobeline from lobelia.

(2) Derivatives of nicotinic acid , including arecoline from areca .

(3) Derivatives of both pyridine and pynolidine, including nicotine from
tobacco .

The important alkaloidal drugs and their alkaloids that are classified in
this group are areca, arecoline hydrobromide , lobelia ,lobeline and icotine.


Biosynthesis of Pyridine-Piperidine Alkaloids
,
Tracer studics have shown that ornithine is incorporated
into nicotine by tobacco plants.
This incorporation resuitsi n a symmetric labeling pattern of nicotine .
Nicotine is primarily a product of root metabolism, but the formation of small amounts , as well as subsequent reactions such as the demethylation of nicotine , can occur in the leaves of plants .