Carpensterol: a new steroid from the ethyl acetate fraction of the fruits of Solanum aculeastrum Dunal (Solanaceae) with antimicrobial activities

Abstract

From the ethyl acetate soluble fraction obtained by liquid-liquid partitioning of the hydro-ethanolic crude extract of Solanum aculeastrum fruits (Solanaceae), one new steroid (carpensterol, 1) and five other well known (2-6) were isolated. Their structures were elucidated by analysis spectroscopic and spectrometric data as well as comparison to data reported in the literature. The evaluation of their antimicrobial activities using the broth microdilution method revealed that, compound 4 (MIC = 4.8 µg/mL) exhibited the greatest activity against Escherichia coli, with an MIC value lower than that of the reference drug, ciprofloxacin (MIC = 256 µg/mL). Additionally, compounds 1 and 4 exhibited moderate activity against Staphylococcus aureus and Salmonella thyphi (MIC = 78.125 μg/mL). These results provide baseline information for the potential use of the isolated steroids.