Flavonoids from Three Ethiopian Species of Premna

Abstract

Two novel hepta-oxygenated flavonols have been isolated from the aerial parts of Premna oligotricha and identified, primarily on the basis of NMR spectroscopy, as 3,5,5'-trihydroxy-6,7,3',4'-tetramethoxyflavone (2) and 3,5,7,5'-tetrahydroxy-6,3',4'-trimethoxyflavone (3). Known flavonoids, with lower levels of oxygenation were obtained from two other Premna species, P. schimperi and P. recinosa. © 1992, Walter de Gruyter. All rights reserved.