Page 86 - phytochemistry II -pharmD general

Vincamine

Another medicinally important Vinca alkaloid is the monomeric alkaloid
vincamine; the structure of which is also given, showing it as indole monomer.

Vincamine is obtained from Vinca minor, and is used to enhance or increase
blood flow and cerebral circulation. It is also said to facilitate cerebral metabolism,
and hence increases general activity. It is indicated in cerebral vascular deficiency
and atherosclerosis, especially in elderly patients (Geriatric medicine).

Vincamine

2. Dimeric Vinca Alkaloids (Vindoline + Catharanthine Units)

Vinblastine and vincristine
These are dimeric alkaloids having indole and dihydro-indole (indoline)

nuclei. They differ in the presence of N-methyl group in vinblastine and N-formyl
group in vincristine. They have closely related structures.

N

N
H3COOC

N

H3CO N OCOCH3
HO COOCH3
Vincristine
Vinblastine R

R = CHO
R = CH3

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