Analysis of Health-Associated Phytochemical Compounds in Seven Hypoxis Species

Abstract

Some species of the genus Hypoxis within the Hypoxidaceae family are known to contain phenolic glycosides that have different clinical functions. In the African continent Hypoxis species are regarded as valuable medicinal plants that have been used for decades by traditionalists and natives to treat numerous ailments. The corms and rhizomes of the geophytes contain hypoxoside, a norlignan diglucoside, which is one of the important phytochemicals with medicinal functions found in Hypoxis. In this study corm extracts of seven species: H. acuminata, H. argentea, H. filiformis, H. gerrardii, H. hemerocallidea, H. iridifolia and H. parvifolia were analyzed for the presence of ellagic acid, total phenolic content (TPC) and hypoxoside. Extracts of H. iridifolia and H. gerardii had the highest levels of total phenolic content of 369.6 μg/g and 318.2 μg/g, respectively, compared to the rest of the species. Hypoxoside was found to be present in corm extracts of all the species in varying proportions. H. gerrardii, H. argentea and H. filiformis had the highest relative hypoxoside content of 7.1%, 6.6% and 6.6%, respectively. It is interesting to note that Hypoxis hemerocallidea, the most commonly used species for medicinal extracts contained a much lower level of hypoxoside than most of the other species. Our study included species that have not been previously analyzed for either TPC or hypoxoside presence such as H. filiformis and H. gerrardii, thus providing novel information regarding the medicinal status and biochemical compounds of these Hypoxis species.