Page 238 - PG 504-theoretical notes-phyto-1-2024-2025..

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

▪ As antidote in barbiturates poisoning.

▪ As analeptic.
c) Diterpenes

1) Quassin
It is the main constituent of quassia wood; the stem wood of Picrasma excela (family

Simarubaceae). Quassin is a molecular terpenoid complex mixture of picrasmin (isoquassin) and
neoquassin.

Preparation:

• The aqueous decoction of quassia wood is concentrated to the original weight of wood used,

neutralized with sodium carbonate.
• Tannic acid solution is added to precipitate quassin tannate, and filtered.

• The precipitate is triturated with lead carbonate or lead oxide to form lead tannate and to liberate
quassin, and dried on a water bath.

• The obtained mass is powdered and then extracted with 80% alcohol.

• The combined alcoholic extract is concentrated and left for quassin to be crystallized.

Chemical test

1) Crystals of quassin gives a red color with sulfuric acid and sucrose.
2) Alcoholic solution of quassin gives with phloroglucin /HCl a crimson red color.

OCH 3
O CH 3
O H
CH 3
H 3 CO
H CH 3

O
O
H H
CH 3
Quassin

Uses:

1) Bitter tonic

2) Anthelmintic for threadworms as enema.
3) Insecticide.

219