Bio‐guided fractionation of ( <scp> 9 <i>Z</i> </scp> )‐5,8,11‐trihydroxyoctadec‐9‐enoic acid from <scp> <i>Abelmoschus sagittifolius</i> </scp> root as a potent <i>α</i> ‐glucosidase inhibitor: An integrated <scp> <i>in vitro</i> </scp> and <scp> <i

Abstract BACKGROUND Abelmoschus sagittifolius stands out as a valuable medicinal source for developing functional food targeting type 2 diabetes. This study investigated the α ‐glucosidase inhibitory potential of an active fraction obtained from A. sagittifolius roots (ASR), enriched in (9 Z )‐5,8,11‐trihydroxyoctadec‐9‐enoic acid (OA), using both enzyme kinetics and molecular docking analyses. The effect of simulated digestion and in silico acute oral toxicity was also evaluated. RESULTS The bioactive fraction, with OA as major component, exhibited strong α ‐glucosidase inhibitory activity [half‐inhibitory concentration (IC 50 ) = 15.96 μg mL −1 ], which was markedly higher than acarbose (IC 50 = 2109.51 μg mL −1 ) and palmitic acid (IC 50 = 618.93 μg mL −1 ). Kinetic analysis indicated that OA acts as a mixed inhibitor, with K i &lt; K i ′ , suggesting stronger affinity for the free enzyme than for the enzyme–substrate complex. Molecular docking supported these findings by revealing stable binding of OA within the catalytic pocket of α ‐glucosidase through multiple hydrogen bonds and hydrophobic interactions. The reduction in bioaccessibility of OA through gastrointestinal tract indicates it is less accessible in the digestive system. Qualitative and quantitative in silico acute oral toxicity analysis suggested OA to be a non‐toxic substance. CONCLUSION This study provides the first investigation into the potential of an OA enriched fraction and its inhibitory mechanism, highlighting OA as a promising bioactive compound for the development of functional foods or nutraceuticals aimed at managing type 2 diabetes. However, further studies, including enzyme‐based validation, toxicity evaluation, bioavailability assessment and clinical investigation, are required to comprehensively confirm the efficacy and safety of OA as a potent α ‐glucosidase inhibitor. © 2026 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley &amp; Sons Ltd on behalf of Society of Chemical Industry.