PHARMACOGNOSTIC SPECIFICATIONS AND COUMARIN CONTENTS OF ALYXIA REINWARDTII AND EUPATORIUM STOECHADOSMUM

Abstract

Alyxia reinwardtii Blume inner bark and Eupatorium stoechadosmum Hance whole plants have been used in traditional Thai medicine for a long time. This study was carried out to investigate the pharmacognostic specifications by qualitative and quantitative analyses as well as coumarin contents of A. reinwardtii inner bark and E. stoechadosmum whole plants. The samples were collected from 15 different sources throughout Thailand. Macroscopic and microscopic characteristics of two crude drugs were illustrated. The physicochemical properties of A. reinwardtii dried inner bark including loss on drying, total ash, acid- insoluble ash, water soluble extractive, ethanol soluble extractive, moisture and volatile oil contents were found to be 8.9±0.2, 7.7±0.1, 1.4±0.1, 16.5±0.1, 8.9±0.3, 11.9±0.2 and 0 % by weight, respectively. The physicochemical propoties of E. stoechadosmum whole plants were found to be 8.7±0.1, 9.5±0.3, 2.6±0.2, 27.8±0.4, 9.4±0.6, 13.2±0.3 and 0.14±0.0 % by weight, respectively. Coumarin in dichloromethane extract of A. reinwardtii dried inner bark and E. stoechadosmum dried whole plants were analyzed by thin layer chromatography (TLC) using silica gel 60 GF254 as stationary phase. Hexane and ethyl acetate (1:1) were used as mobile phase for A. reinwardtii. In case of E. stoechadosmum TLC procedure, first step developed with chloroform, and then with toluene, ethyl acetate and acetic acid (97:10:3). The coumarin contents were evaluated both TLC-densitometry performed using winCATS software and image analysis using imageJ software. The coumarin contents in A. reinwardtii crude drugs were found to be 0.77±0.04 and 0.75±0.01 g/100 g by those methods respectively. The coumarin contents in E. stoechadosmum crude drugs were found to be 0.44±0.02 and 0.45±0.04 g/100 g by those methods respectively. The coumarin contents between both methods were not statistically significant different (p>0.05) by paired t-test. According to ICH guideline, TLC-densitometry and TLC image analysis using ImageJ software showed validity and reliability for coumarin quantitations in A. reinwardtii and E. stoechadosmum crude drugs. The chemical compositions of E. stoechadosmum volatile oils from 15 sources were analyzed by GC-MS. The result showed that the main component was binapacry (16.74±5.38%). E. stoechadosmum from 15 sources could be divided into two groups based on the dendrogram of volatile oil compositions constructed by UPGMA cluster analysis. This study provided scientistic evidences for identification, authentication, and quality control of A. reinwardtii and E. stoechadosmum crude drugs.