Search results for "Bulbine"
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Joziknipholones A and B: The First Dimeric Phenylanthraquinones, from the Roots ofBulbine frutescens
2007
From the roots of the African plant Bulbine frutescens (Asphodelaceae), two unprecedented novel dimeric phenylanthraquinones, named joziknipholones A and B, possessing axial and centrochirality, were isolated, together with six known compounds. Structural elucidation of the new metabolites was achieved by spectroscopic and chiroptical methods, by reductive cleavage of the central bond between the monomeric phenylanthraquinone and -anthrone portions with sodium dithionite, and by quantum chemical CD calculations. Based on the recently revised absolute axial configuration of the parent phenylanthraquinones, knipholone and knipholone anthrone, the new dimers were attributed to possess the P-co…
Quinones and Benzophenones from the Medicinal Plants of Africa
2013
In this chapter, we discuss the chemistry of quinones and benzophenones: classification, nomenclature, biosynthesis, biological activity, and their distribution in nature. Genera such as Newbouldia, Kigelia, Aloe, Euclea, Diospyros, Bulbine, Rumex, and Kniphofia are rich sources of quinines, while the Guttiferae are rich in polyprenylated benzophenones. Most of these African species offer novel derivatives with interesting biological activities, suggesting that these species are potential sources of new drug candidates if properly investigated.