Triterpene saponins and flavonoids in the seeds of Trifolium species.

Seeds of 57 species of the genus Trifolium have been studied for the occurrence and concentration of soyasapogenol B glycosides and flavonoids. It was shown that all tested species contained soyasaponin I and in some species astragaloside VIII and/or 22-O-glucoside and 22-O-diglucoside of soyasaponin I were also present. Total concentration of saponins ranged from trace amounts up to 10 mg/g(DM). It was suggested that soyasapogenol B glycosides could be recognized as chemotaxonomic character of Fabaceae family. All but three tested species contained flavonoids. The majority of species contained quercetin as a sole flavonoid or in the mixture with a number of unidentified flavonoid components. Concentration of quercetine in some species was at the level of about 3 mg/g(DM). This high quercetin concentration and soyasaponin occurrence makes the seeds of some Trifolium species a potential source of health beneficial phytochemicals, to be used in human nutrition.