IntroductionHigher plants synthesize a wide variety of phenolic compounds during their regular growth and development. These phenolic compounds are products of the phenylpropanoid biosynthetic pathway and generally accumulate at relatively high concentrations in cell vacuoles, and they are usually chemically associated with sugars (Coronado et al., 1995). Flavonoids are found throughout the plant kingdom, whereas isoflavones are more restricted and particularly prevalent in the subfamily Papilionoideae of Fabaceae.The Fabaceae taxonomic class includes a variety of plants with significant economic value, including soybean, alfalfa, clover, pea, and various beans. These leguminous plants accumulate a wide range of phenolic secondary compounds, including isoflavonoid conjugates (Kessmann et al., 1990b). An important group of legume natural products, isoflavones, have been better understood at the molecular genetic level (Dixon et al., 1995;Dixon 1999;Dixon et al., 2004). These compounds function as preformed or inducible antimicrobial, antiinsecticidal compounds, signaling molecules in symbiotic nodulation by Rhizobium bacteria, or as allelopathic agents. In vitro cultures, which are a key method for secondary metabolite production, have been established for some of the legumes. Cell suspension cultures of Glycine max contained higher amounts of total isoflavones than that of the callus cultures (Federici et al., 2003). Genistein, daidzein, formononetin, and biochanin A were observed in the cell suspension cultures of Medicago truncatula (barrel medic), which is the model legume in plant functional genomics (Suzuki et al., 2005;Farag et al., 2007). T. pratense, usually called red clover, has a variety of isoflavones, including biochanin A, genistein, daidzein, and formononetin, which were reported in high concentrations (Setchell et al., 2001;Khaosaad et al., 2008). Isoflavones may act as an estrogen agonist or antagonist, depending on the compound and content present in the organism (Dog, 2005). Thus, red clover has become popular as a food supplement for the amelioration of menopausal disorders (Dornstauder et al., 2001;Beck et al., 2003). Although red clover blossoms have been used in traditional herbal medicine for centuries, it is the semipurified isoflavone leaf extracts for relief of menopause-related symptoms that interest