Quality Assessment of Radix Sophorae Tonkinensis by RP-HPLC

Purpose To assess the quality of the Chinese crude drug radix sophorae tonkinensis (the dried roots of Sophora tonkinensis Gapnep.). Methods A reversed-phase high performance liquid chromatographic (RP?HPLC) method was used to determine the contents of the two main alkaloids, oxymatrine and matrine, in the crude drugs purchased from 15 different districts. Results The two compounds could be well separated from other constituents and there was a good linear relationship within the range of 0.8-8.0 μg (r=0.999 9, n=6) for oxymatrine and 0.2-2.0 μg (r=0.999 8, n=6) for matrine.The ave-rage recoveries of oxymatrine and matrine were 98.4% and 102.5% respectively.The content of the alkaloids varied greatly, and it ranged from 0.16%-2.47% for oxymatrine,0.09%- 0.69% for matrine and 0.76%-3.16% for the total content of the two alkaloids.The content of oxymatrine was much higher than that of matrine and was found to exist more stably, and the variation of the content of oxymatrine kept consistent with that of the total value of the two alkaloids. Conclusions The content of oxymatrine or the total content of matrine and oxymatrine could be used as the marker for the quality control of radix sophorae tonkinensis.