Separation and Activity against Drug-resistant Bacteria of Tetrandrine and Fangchinoline in Lipophilic Akaloids from Stephania tetrandra

Tetrandrine and fangchinoline were separate in total alkaloids from Stephania tetrandra and the activities against drug-resistant bacteria in-vitro were investigated. Preparative medium pressure liquid chromatography and semi-preparative high performance liquid chromatography were applied to separate and purify tetrandrine and fangchinoline; Agar dilution method was used to test the anti-drug–resistant bacteria activity and determine the minimum inhibitory concentration (MIC) of MRSA 13366 and ESBLproducing Escherichia coli 13025. Tetrandrine and fangchinoline were identified by TLC and NMR spectra; The viable count absorbance regression equations were Y=9.5715x-0.3439(R2=0.9907) for MRSA 13366 and Y=8.6245x-0.1802(R2=0.9972) for ESBL-producing Escherichia coli 13025; MICs of tetrandrine were 80 μg/ml for MRSA 13366 and 160 μg/ml for ESBL-producin E. coli 13025; MICs of fangchinoline were 160 μg/ml for MRSA and 320 μg/ml for ESBL-producing Escherichia coli 13025. High performance liquid chromatographic method was considered convenient, fast and high-purity method to separate and purify tetrandrine and fangchinoline from total lipophilic alkaloids. Both tetrandrine and fangchinoline showed significantly inhibiting activity on MRSA and ESBL-producing Escherichia coli especially for tetrandrine..