Isolation and Characterisation of Two Quercetin Glucosides with Potent Anti‐Reactive Oxygen Species (ROS) Activity and an Olean‐12‐en Triterpene Glucoside from the Fruit of <i>Abelmoschus esculentus</i> (L.) M <scp>oench</scp>

Abelmoschus esculentus (Okra) is used in the traditional treatment of cancer, hyperlipidaemia and hyperglycaemia. We, therefore, investigated its composition potential cytotoxic or antioxidant properties that might underlie phytotherapeutic applications. Its methanolic fruit extract yielded compounds 1, 2 3, identified through NMR, UV MS analyses as olean-12-en-3-O-β-d-glucopyranoside, isoquercitrin (quercetin glucoside) 5,7,3′,4′-tetrahydroxy-flavonol-3-O-[β-d-glucopyranosyl-(1→6)]-β-d-glucopyranoside diglucoside), respectively. Following 48 h exposure, oleanene glucoside was mildly toxic to HeLa MRC5-SV2 cancer cells, not except at 100 μg/ml HeLa, quercetin diglucoside elicited no toxicity. In a 2′,7′-dichlorofluorescein diacetate (DCFDA) assay intracellular levels reactive oxygen species (ROS), hydrogen peroxide increased ROS levels, an effect affected by but protected against diglucoside, with IC50 values, respectively, 2.7±0.5 1.9±0.2 (3 post-treatment) 2.0±0.8 1.5±0.4 (24 post-treatment.) This first report this skeleton triterpenoid plant. The work provides some insight into why plant included remedies for cancers, cardiovascular complications diabetes, reveals it source novel therapeutics.