Page 74 - phytochemistry II -pharmD general

b. Lysergic acid amides
i. Simple lysergic acid amides

All these are water-soluble alkaloids of relatively low molecular weights as
they are all amides of lysergic acid with simple amines.

The simplest example of these amides is ergine (lysergic acid amide itself)
and erginine (isolysergic acid amide), that have been isolated as naturally existing
alkaloids (water soluble). However, the most important member of this class is the
potent oxytocic alkaloid ergonovine (ergometrine) which is the amide of l-(or laevo)
lysergic acid with 2-aminopropanol.

Ergonovinine (or ergometrinine) is its diastereomer (at carbon No 8, bearing
the carboxyl group). So, the latter alkaloid is the amide of d-lysergic acid with 2-
aminopropanol.

Another example of this class is lysergic acid diethylamide (LSD).

Name R1 R2 R3

Ergine H H H

Ergonovine H CH(CH3)CH2OH H

LSD H CH2CH3 CH2CH3

Ergometrine

Ergometrine causes vigorous contraction of the uterus. It is mainly used as
an oxytocic in order to aid delivery or to prevent postpartum hemorrhage. It has
certain advantages over the water insoluble ergot alkaloids in that, it does not
produce vomiting or nausea, and possesses an oxytocic activity. Methergine or
(methylergonovine) (As maleate) is a blood vessel constrictor and smooth
muscle agonist most commonly used to prevent or control excessive bleeding

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