Withanolides from Discopodium penninervium.

Discopodium penninervium is a medicinal plant endemic to Ethiopia. Its twigs extract led to the isolation of three new withanolides, discopodinolides A - C, and four known analogues. The structures of the compounds were elucidated using NMR, HRMS data analyses, and literature data. The relative configurations were defined by single-crystal X-ray crystallography and NOESY correlations. The antibacterial efficacy of the isolated compounds was evaluated against four commonly dispersed environmental strains of Escherichia coli, Bacillus subtilis, Bacillus pumilus, and Bacillus megaterium. Discopodinolides B and C exhibited moderate antibacterial activities against the pathogenic strains of E. coli, B. subtilis, and B. megaterium.