Page 88 - phytochemistry II -pharmD general

They are also extremely toxic (as strychnos alkaloids). The crude drug
gelsemium is included in the British Herbal Pharmacopoeia for the treatment of
migraine and neuralgia.

O
CH3

N

NO

Gelsemine

Carboline alkaloids

The most prominent examples are:
▪ The rauwolfia alkaloids (mainly reserpine).
▪ The yohimba alkaloids (mainly yohimbine), and
▪ The peganum harmala alkaloids (mainly harmine and harmaline).

The alkaloids of this group are more correctly considered as -carboline
derivatives, rather than indole derivatives as they constitute a pyridine ring fused
to an indole skeleton.

From Rauwolfia and some Yohimbe species, a number of -carboline
alkaloids were isolated and identified (during the past 50 years).

a. Peganum harmala alkaloids

Harmine and harmaline

N N
N
H3CO N H3CO
H H CH3
CH3
Harmaline
Harmine

Harmine and harmaline (5, 6 dihydroharmine) occurs in the seeds of harmal
(Peganum harmala) family Nitrariaceae to the extent of 2-7%.

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