Development of a validated HPLC method for the simultaneous determination of flavonoids in Cuscuta chinensis Lam. by ultra-violet detection

BACKGROUND: Cuscuta species known as dodder, have been used in traditional medicine of eastern and southern Asian countries as liver and kidney tonic. Flavonoids are considered as the main biologically active constituents in Cuscuta plants especially in C. chinensis Lam. OBJECTIVE: In the present study, a fast, simple and reliable method for the simultaneous determination and quantization of C. chinensis flavonols including hyperoside, rutin, isorhamnetin and kaempferol has been developed. MATERIALS AND METHODS: The chromatographic separation was carried out on a reversed phase ACE 5 C(18) with eluting at a flow rate of 1 ml/min using a gradient with O-phosphoric acid 0.25% : acetonitrile for 42 min. UV spectra were collected across the range of 200–900 nm, extracting 360 nm for the chromatograms. The method was validated according to linearity, selectivity, precision, recovery, LOD and LOQ. RESULTS: The method was selective for determination of rutin, hyperoside, isorhamnetin and kampferol. The calibration graphs of flavonols were linear with r(2) > 0.999. RSDs% of intra- and inter-day precisions were found 1.3&3.4 for rutin, 1.5&2.8 for hyperoside, 1.3&3.3 for isorhamnetin and 1.7 & 2.9 for kaempferol which were satisfactory. LODs and LOQs were calculated as 1.73 & 8.19 for rutin, 0.09 & 4.19 for hyperoside, 2.09 & 6.3 for isorhamnetin and 0.18 & 0.56 for kaempferol. The recovery averages of above-mentioned flavonols were 90.3%, 97.4%, 98.7% and 90.0%, respectively. CONCLUSION: The simplicity of the method makes it highly valuable for quality control of C. chinensis according to quantization of flavonols.