Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9753361 | Journal of Chromatography B | 2005 | 6 Pages |
Abstract
A simple liquid chromatographic method was developed for the simultaneous determination of flavonoids from Orthosiphon stamineus Benth, namely sinensitin, eupatorin and 3â²-hydroxy-5,6,7,4â²-tetramethoxyflavone, in plasma. Prior to analysis, the flavonoids and the internal standard (naproxen) were extracted from plasma samples using a 1:1 mixture of ethyl acetate and chloroform. The detection and quantification limits for the three flavonoids were similar being 3 and 5Â ng/ml, respectively. The within-day and between-day accuracy values, expressed as percentage of true values, for the three flavonoids were between 95 and 107%, while the corresponding precision, expressed as coefficients of variation, for the three flavonoids were less than 14%. In addition, the mean recovery values of the extraction procedure for all the flavonoids were between 92 and 114%. The calibration curves were linear over a concentration range of 5-4000Â ng/ml. The present method was applied to analyse plasma samples obtained from a pilot study using rats in which the mean absolute oral bioavailability values for sinensitin, eupatorin and 3â²-hydroxy-5,6,7,4â²-tetramethoxyflavone was 9.4, 1.0 and 1.5%, respectively.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Yit Hong Loon, Jia Woei Wong, Siew Ping Yap, Kah Hay Yuen,