Pharmacognostic specification and coumarin content of Alyxia reinwardtii inner bark

Abstract

Alyxia reinwardtii Blume is used in traditional medicine for a long time. This study was carried out to investigate the standardization parameters by qualitative and quantitative analyses as well as coumarin content of A. reinwardtii inner bark. Loss on drying, total ash, acid-insoluble ash, water soluble extractives, ethanol soluble extractives and moisture contents were found to be 8.1 ± 0.2, 7.6 ± 0.1, 1.4 ± 0.1, 16.5 ± 0.1 , 8.9 ± 0.3 and 11.9 ± 0.2% by dry weight, respectively. Coumarin in dichloromethane extract of A. reinwardtii inner bark was analysed by thin layer chromatography (TLC) using silica gel 60 F 254 as stationary phase, hexane and ethyl acetate (1 : 1) as mobile phase. The content was evaluated by image analysis using image J software. The regression line of method was polynomial in range of 0.075 - 1.2 mg/spot, and correlation coefficients (R 2) were 0.99. The repeatability and intermediate precisions were between 0.5 - 7.1% RSD. The percent recovery was found to be 96.8 - 107.3%. The robustness evaluated by slightly variation in mobile phase ratio was 1.3% RSD. Limit of detection (LOD) and limit of quantitation (LOQ) were 0.05 and 0.16 mg/spot respectively. The coumarin content in A. reinwardtii inner bark crude drug was found to be 0.75 ± 0.01% by dry weight. This study provided pharmacognostic specification toward fundamental standardization of A. reinwardtii inner bark. Additionally, the simple TLC with image analysis can be applied to quantitatively determine coumarin in plant material.