Distribution of triterpene acids and their derivatives in organs of cowberry (Vaccinium vitis-idaea L.) plant.

Abstract

Wild berries of the genus Vaccinium have become increasingly popular in human health promotion due to their nutritional and medicinal properties. Some striking divergence of opinion about the content of triterpenoids in these plants still exists, meanwhile, this very large class of natural isoprenoids exhibits a wide range of biological activities and hence is of growing research interest. An investigation of triterpenoidal constituents from the cowberry (Vaccinium vitis-idaea L.) plant led to the isolation of two isomeric acids: oleanolic and ursolic and the occurrence of their derivatives in this plant was demonstrated for the first time. Free triterpene acids as well as small amounts of their bound forms (presumable glycosides and glycoside esters) occur in fruits and the vegetative part of the plant, however, in various amounts and different ratios. The total content of both acids was the highest in organs regarded as traditional herbal resources, namely fruits and leaves (1 and 0.6% of dry mass, respectively), whereas it was markedly lower in stems and rhizomes. However, the rhizomes were in turn the plant organ containing relatively the highest amount of the bound forms of both acids (0.01% of dry mass). Ursolic acid was dominant in the whole plant, but the ratio of oleanolic to ursolic acid was significantly different in individual organs, decreasing from the upper (fruits 1:2.4, leaves 1:2) to the lower (stems 1:3.5, rhizomes 1:5.2) parts of the plant. This pattern of distribution of triterpenoids in the plant may have an important physiological and ecological meaning.