Quality control method of Tibetan medicine Saussureae obvalltae

Abstract

To control the quality of Tibetan medicine Saussureae obvalltae, the quality control method and standard were established in this study. The water content, total ash, acid-insoluble ash and ethanol-soluble extractives of Saussureae obvalltae were determined according to the methods recorded in appendix of Chinese Pharmacopeia(2010 edition). Microscopical identification was performed for the plant and powder of the leaves. The TLC method was established, with chlorogenic acid and rutin as control substances, and a mixture of acetate-btuanone-formic acid-water (10∶6∶1∶2) as developing solvent and silica gel G as thin layer plate. Agilent ZORBAX Eclipse XDB-C₁₈ (4.6 mm×250 mm, 5 μm) column was adopted and eluted with the mobile phase of acetonitrile-0.1% phosphoric acid (17∶83) in a gradient mode at a flow rate of 1.0 mL•min⁻¹. The column temperature was 40 ℃ and the detection wavelength was 350 nm. As a result, the plant and leaves of Saussureae obvalltae of different origins showed constent microscopic features. Chlorogenic acid, rutin and the other constituents were well separated on TLC detected under the sun light. According to the results of the methodological study, chlorogenic acid and rutin were in good linear correlation in the ranges of 0.119 2-0.715 4 μg(r=0.999 9) and 0.160 7-0.964 4 μg(r=1.000), and the average recoveries were 105.4% (RSD 1.4%) and 99.50% (RSD 0. 91%), respectively. The content of ethanol-soluble extractives, water content, total ash and acid-insoluble ash were 26.01%-31.59%, 7.16%-8.04%, 8.46%-11.14%,0.50%-1.87%, respectively. According to the study, the established method was specific and accurate, which could be used for the quality control of this drug.