Rotenoids and Isoflavones from Xeroderris stuhlmannii (Taub.) Mendonça & E.P. Souza and Their Biological Activities
The phytochemical study of the ethanolic extract of the leaf of Xeroderris stuhlmannii led to the isolation of five hitherto unreported compounds including two isoflavones ( 1 – 2 ), and three rotenoids ( 3 – 5 ), along with eight known isoflavonoid derivatives ( 6 – 13 ) and one pterocarpan derivative ( 14 ). The structures of the new compounds and those of the known ones were established by the spectroscopic (1D and 2D NMR) and spectrometric (HRESIMS) techniques as well as a comparison of their spectroscopic data with those reported in the literature. The leaf extract, fractions, and isolated compounds were tested for their antibacterial effects against nine bacterial strains. Compounds 3 , 8 , 11, and 12 showed a significant antibacterial effect, with a minimum inhibitory concentration (MIC) value of 62.5 µg/mL each, against Salmonella typhi , Staphylococcus aureus , Klessiella pneumonae , and Escherichia coli , respectively. In addition, the leaf extract, fractions, and isolated compounds were tested for their antifungal effects against four fungal strains. The hexane fraction showed a significant antifungal effect with an MIC value of 125 µg/mL against Candida parasilosis , whereas compounds 3 , 8 , and 12 showed significant antifungal activity with an MIC value of 62.5 µg/mL, each against Candida parasilosis , Candida albicans , and Candida krusei , respectively.