| The genus Trifolium belongs to Leguminosae family, which comprise 360 species distributed in and subtropical zone of Asian, America, European and Oceanica, and there are 8 species are commenly seen in China and white clover, red clover, alsike clover were spread most widely. Chemical constituents of Trifolium Pratense L. have been studied extensively. Previous phytochemical investigations on this species revealed that isoflavone which including aglycones, glycosides, glycoside malonates, coumarins and amides are largely represented in this genus. More than 50 isoflavones were detected in red clover, such as Biochanin A , Formononetin , Genistein , Daidzein , Prunetin , Pratensein , Pseudobaptigenin , Calycosin and so on. Isoflavone and Flavone constituents have been reported to possess anticancer, antimicrobial, antioxidant, anti-inflammatory and immunosuppressive activities. Red clover has been widely used as a folk medicine for clearing away coughing, expelling eczema as well as psoriasis and preventing cancer, cardiovascular disease and osteoporosis. They may play an important role in cancer prevention, moderation of menopausal symptoms, and other healthy effects. Chemical studies of the other cpmpounds except isoflavone have been conducted a few report previously.In our investigation of chemical constituents from Trifolium Pratense L.. (collected in Hubei province in China), fifteen compounds were isolated by the methods of normal-phase and reverse-phase silica gel column chromatography, HPLC, etc. Two new compounds were named as 3-Methylchromone-7-α-O-glucoside-2'-O-rhamoside (13) and Trihydrodehydrodiconiferyl alcohol 9'-O-glucoside (14). Other thirteen known compounds were identified as: 1-hydroxy-5, 6, 7-thrimethoxy-xanthone (01), Methyl-3-oxoolean-12-en-28-oate (02), Stigmast-4-en-3-one (03), Stigmast-4-en-3, 6-dione (04),α-stigmast-4-en-3, 6-dione (05), Quercertin-3-O-α-L-rhamoside (06), Hyperin (07), Quercertin-3-O-α-D-glucoside (08), Isorhamnetin 3-O-β-D-glucopyranoside (09), Aurilatin (Quercertin-3-O-α-L-arabinofuranoside) (10), Quercertin 3-O-α-L-arabinpyranoside (11), 7-glupyrancosyl-3, 5-dihydroxyflavanone (12) and Physcion (15). Nine compounds including 01, 02, 03, 04, 05, 10, 11, 12 and 15 were isolated from this plant for the first time. |
