Page 330 - Pharmacognosy 2 PG303

Pharmacognosy-2 (PG303) Level 2 Clinical Pharmacy-Pharm D

Tests for Identity
▪ Determination of ether extractive: Shake frequently for 6 h., in a 100 ml closed
flask, 1 g of finely powdered Scammony resin with 50 ml of freshly re-
distilled ether, filter, then wash the residue with 10 ml of ether, and evaporate
the mixed filtrates; the residue from the Mexican Scammony resin, after
drying at 100 ºC., weighs not less than 0.6 g, while that from the Levant
Scammony resin weighs not less than 0.75 g.
▪ It gives negative tests for Guaiacum resin and for Colophony (see under Jalap
resin).

Uses
Scammony resin is a cathartic with haydragogue activity.

GUM-RESINS

Resins may also occur in association with gum and are called gum-resins. The
true medicinal gum-resin is represented, by Gamboge which is free of volatile oil.

Gamboge

Gamboge is a gum-resin obtained from Garcinia Hanburyi Hooker filtus
(Fam. Guttiferae). The tree attains about 15 metres in height and grows in
Cambodia, Thailand, and Cochin China.

Preparation
Spiral incisions through the bark from the ground upward are made. This
permits the resinous emulsion present in the cortex and phloem to exude. It is usually
collected in bamboo nodes, and when solidified, these are cracked open to give what
is called Pipe Gamboge which is the best commercial variety. That which hardens
on the ground or collected in leaves, known as Cake Gamboge, is more
contaminated with dirt.

Description
Gamboge occurs in cylindrical pieces frequently hollow in the centre, of
variable lengths, 2-5 cm in diameter. Externally, it is reddish brown to dark orange,

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