Rare phenolic structures found in the aerial parts of Eriosema laurentii De Wild

Recent pharmacological and toxicological investigations of Eriosema laurentii (Leguminosae) have underlined the plausibility of the use of this plant in traditional African medicine. A very complex pattern of phenolic compounds was detected in the tested extracts. Based on these preceding results a detailed phytochemical study was performed and resulted in the isolation and identification of eleven compounds. All are reported in this plant for the first time and four of those are previously undescribed secondary metabolites: 3,4',6,8-tetrahydroxyflavanone-7-C-glucoside and 3,4',6,8-tetrahydroxyflavone-7-C-glucoside with an extremely rare substitution pattern as well as 1-[2,4-dihydroxy-3-(2-hydroxy-3-methylbut-3-en-1-yl)phenyl]-3-phenylpropan-1-one and 1[2,4-dihydroxy-3-(2-hydroxy-3-methylbut-3-en-1-yl)phenyl]-3-(4-methoxyphenyl)-propan-1-one. Their structures were elucidated unambiguously by extensive MS- and NMR-experiments. (C) 2016 Elsevier Ltd. All rights reserved.