Investigation on isoflavonoids of Trifolium longidentatum Nabelek

Trifolium species are used in traditional medicine to treat several disorders. Among them, Trifolium pratense are a potent natural source of isoflavonoids. Recent researches have shown that Trifolium pratense (red clover) extracts contain significant high amounts of all the four major estrogenic isoflavones genistein, daidzein, and their methyl ether derivatives biochanin A and formononetin. Therefore, red clover extracts indicate the potential application of red clover preparations for alternative hormone replacement therapy as selective estrogen receptor modulators and in the management of menapouse.Genus Trifolium is represented by 130 taxons in the flora of Turkey and, up to date, no any analytical study has been performed on isoflavonoids of Trifolium longidentatum. In this study, the methanolic extracts prepared from the aerial parts of T. longidentatum have been analyzed to determine the concentrations of four isoflavones, daidzein, genistein, formononetin and biochanin A, by HPLC. Chromatographic separation was carried out by using a mobile phase containing methanol, acetate buffer (pH=4.75) and acetonitrile (gradient elution) on the reversed phase column, Agilent Eclipse XDB-18 (15 cm x 4.6 mm i.d.). The content of daidzein, genistein, formononetin, and biochanin A in the extracts of T. longidentatum were found as 0.0095 %, 0.0056 %, 0.0021 ve 0.0073 %, respectively.