A new polyphenol and its derivatives with <i>α</i>-glucosidase and nitric oxide production inhibitory activities from <i>Ochna integerrima</i> species in Vietnam

A new dihydroflavonol, ochnaflavonol A (<b>1</b>), together with five known isolates (<b>2–6</b>), was obtained from the dichloromethane extract of the stems and branches of <i>Ochna integerrima</i>. The structure of <b>1</b> was elucidated using NMR, HR-ESI-MS, and ECD spectra. Structural elucidation of (<b>2–6</b>) was done by interpreting NMR spectra and comparing published data. Furthermore, compounds <b>1</b>, <b>2</b>, <b>5</b>, and <b>6</b> were reported to be the first discovered in the <i>Ochna</i> genus. Compounds (<b>1–6</b>) were evaluated for their inhibitory effects on <i>α</i>-glucosidase as well as nitric oxide (NO) production. Among them, <b>3</b> and <b>6</b> exhibited anti-<i>α</i>-glucosidase effect with IC₅₀ values of 88.28 ± 1.38 and 31.6 ± 3.07 μg/ml, respectively. For NO inhibitory, <b>1</b> and <b>6</b> showed inhibitory potency with IC₅₀ values of 185.76 ± 8.21 and 152.62 ± 7.5 μg/ml, respectively. Based on the findings, this ­species shows great potential for antidiabetic treatment.