Quality evaluation of Platycladus orientalis (L.) Franco through simultaneous determination of four bioactive flavonoids by high-performance liquid chromatography.

Platycladus orientalis (L.) Franco (Cupressaceae), a traditional Chinese herb and food additive, has been used for treatments of gout, rheumatism, diarrhoea and chronic tracheitis. To evaluate the quality of P. orientalis (L.) Franco, a sensitive, simple and accurate reversed-phase high-performance liquid chromatographic (RP-HPLC) separation method with a photodiode array detector (DAD) was developed for the determination of four main bioactive flavonoids, rutin, quercitrin, quercetin and amentoflavone. Separation of the four compounds was achieved by the HPLC assay (Agilent Eclipse XDB-C 18 column with mobile phase, methanol-acetonitrile-18 mM sodium acetate buffer (pH 3.5) and recorded at UV 356 nm). This method showed good linear relation in the range of 0.8-80 microg/ml for rutin, 1.84-184 microg/ml for quercitrin, 0.72-72 microg/ml for quercetin and 0.72-72 microg/ml for amentoflavone. The correlation coefficients of the calibration curve for the analysis were all higher than 0.999. In addition, the contents of those four flavonoids in P. orientalis (L.) Franco growing in 12 different locations in China were compared to establish the effectiveness of the method.