Isolation and characterization of a novel glycoside from the inner bark of <i>Sclerocarya birrea</i> : insights into antibiotic and anticancer activity

Phytochemical analysis of the dichloromethane-methanol (1:1) extract from <i>Sclerocarya birrea</i> inner bark led to the identification of three compounds: a novel glycoside, 3α-sorbithoxyglucose (<b>1</b>), and two known compounds, retusasterol (<b>2</b>) and <i>β</i>-sitosterol-3-<i>O-D-</i>glycoside (<b>3</b>), isolated for the first time from this plant. Structural elucidation <i>via</i> NMR confirmed their identities. Cytotoxicity studies against MCF7 breast cancer and DU145, PC3, LNCaP prostate cancer cell lines revealed that compounds <b>1</b> and <b>2</b> lacked inhibitory effects on cell proliferation, while retusasterol exhibited cytotoxicity with CC₅₀ values of 38 μg/mL (DU145), 40 μg/mL (PC3), and 32 μg/mL (LNCaP). However, further analysis indicated that retusasterol promoted tumour cell proliferation. Antimicrobial screening of 3α-sorbithoxyglucose against <i>Bacillus subtilis</i>, <i>Enterococcus faecalis</i>, <i>Staphylococcus epidermidis</i>, <i>Staphylococcus aureus</i>, <i>Mycobacterium smegmatis</i>, <i>Enterobacter cloacae</i>, <i>Proteus vulgaris</i>, <i>Klebsiella oxytoca</i>, <i>Klebsiella pneumoniae</i>, <i>Proteus mirabilis</i>, <i>Escherichia coli</i>, and <i>Pseudomonas aeruginosa</i> revealed MIC values of 15.625-250 μg/mL, suggesting potential as an antimicrobial agent compared to standard antibiotics.