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Clinical pharmacy PharmD program Third level Phytochemistry-1 (PG-504)

I) Phloroglucinol derivatives

▪ Humulone and lupulone

HO
HO OH HO OH

O O O O
Humulone Lupulone

Both occur in hops; the strobiles of Humulus lupulus, family Cannabinaceae.

Preparation:

▪ Hopes strobiles are extracted with alcohol, filtered
▪ The filtrate is heated with animal charcoal, then cooled and filtered.

▪ The precipitate (charcoal with adsorbed bitter principles) is extracted by boiling with alcohol.
The alcoholic extract is evaporated and humulone is extracted from the resinous matter by

boiling water.
▪ The aqueous solution is cooled and shaken with ether.

▪ Ether is evaporated to obtain the bitter principles

Chemical tests:

1) Dissolve in KOH, a yellow colored solution is produced.

2) Alcoholic solution of humulone gives with FeCl3 solution a reddish-violet coloration.
3) Humulone reduces ammoniacal AgNO3 solution to give silver mirror.

Uses:

▪ Hops are mainly used in the preparation of beer.
▪ Sedative action.

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