【Objective】To study the chemical constituents of flavonoids from Hypericum perforatum L..【Methods】The chemical constituents of Hypericum perforatum L.were isolated and purified by chromatography,and their structures were identified on the basis of spectroscopic evidence.【Results】Five compounds from Hypericum perforatum L.were identified as quercetin,avicularin,quercitrin,isoquercitrin and hyperin.【Conclusion】Isoquercitrin is obtained from Hypericum perforatum L.for the first time.

OBJECTIVETo establish quality control criteria for medicinal herb Cajanus cajan based on the determination of longistylin A and longistylin C, two bioactive and specific stilbenes of the plant.

METHODLongistylin A and longistylin C were obtained from the leaves of C. cajan by silica gel column chromatography and identified as marker compounds of this plant by spectroscopic analysis. A RP-HPLC method was established to determine the two compounds.

RESULTLongistylin A and longistylin C were well separated on a Thermo BDS Hypersil C18 column (4.6 mm x 250 mm, 5 microm) with a mobile phase methanol-water (8:2), and showed good linearity in the range of 0.00288 - 0.0576 microg and 0.0112 - 0.224 microg, respectively. The average recoveries were 98.9% and 97.2% with RSD of 2.4% and 2.2% for these two compounds, respectively.

CONCLUSIONThe established analysis method is simple and accurate, whicn can be used for quality control of C. cajan.

Cajanus ; chemistry ; Chromatography, High Pressure Liquid ; methods ; Diethylstilbestrol ; analysis ; isolation & purification ; Drugs, Chinese Herbal ; analysis ; isolation & purification ; Plant Leaves ; chemistry ; Plants, Medicinal ; chemistry