PHARMACOGNOSTIC SPECIFICATION AND QUANTITATIVE ANALYSIS OF STRYCHNINE AND BRUCINE IN STRYCHNOS NUX-VOMICA SEEDS

Abstract

Strychnos nux-vomica L. (Strychnaceae) dried seeds have been used as medicinal and poisonous drug. The seeds which are hard shell and dish shape contain two major alkaloids i.e. strychnine and brucine. The quality specification of S. nux-vomica seeds as well as its strychnine and brucine contents in Thailand needed to be established. Crude drug samples from 15 sources throughout Thailand were collected. The pharmacognostic specification was determined according to WHO guideline. The seeds were exhaustively extracted in ethanol by Soxhlet apparatus. The contents of strychnine and brucine in the extracts were quantified by TLC-densitometric method using silica gel 60 GF254 as stationary phase and toluene: ethyl acetate: diethylamine (7: 2: 1 v/v) as mobile phase. Quantitative analysis of strychnine and brucine were detected at wavelength of 257 and 302 nm at hRf of 50 and 32.5 respectively. The pharmacognostic specification of S. nux-vomica seeds was established in average contents of water content, loss on drying, total ash, acid insoluble ash, water extractive matters and ethanol extractive matters as 8.08 ± 0.99, 8.80 ± 1.31, 1.20 ± 0.09, 0.15 ± 0.06, 13.12 ± 2.92 and 3.90 ± 1.83 g/100g of dry weight respectively. The contents of strychnine and brucine in dried seeds were found to be 1.03 ± 0.51 and 0.46 ± 0.28 g/100g respectively. TLC-densitometric method was demonstrated for its validity in terms of specificity, linearity, accuracy, precision, LOD-LOQ and robustness.