Quantification of rutin, quercitrin and quercetin in Cosmos caudatus Kunth by reverse phase high performance liquid chromatography

Cosmos caudatus is a traditional medicinal plant from the family Compositae. The fresh leaves are consumed as appetizer and for health benefits such as antioxidant activity, to improve blood circulation and to promote the formation of healthy bones. Our study aims to develop a reverse phase high performance liquid chromatography method for quantification of rutin, quercitrin and quercetin in C. caudatus extracts. The method was validated for selectivity, linearity, precision, accuracy and limits of detection and quantification. Selectivity was confirmed based on retention time and ultraviolet-visible spectra; linearity was in the range 0.5-500 mu g/ml at R-2=1.0; the intraday and interday precision was determined as the relative standard deviation of peak area and retention time. Percentage recovery, limits of detection and the limits of quantification of rutin, quercitrin and quercetin were also determined. The reported method was applied for the quantification of the 3 marker compounds in 15 extracts of C. caudatus. Results showed quercitrin as the major constituent in C. caudatus; hence it may be used as a reference compound for standardisation of this medicinal herb. The method can be considered as analytical tool for quality control, stability studies, pharmacokinetics, and standardisation purposes.