INVESTIGATION OF FLAVONOID CONSTITUENTS AND ANTIOXIDANT ACTIVITY OF LEAF EXTRACTS FROM COCCOLOBA UVIFERA (L.) L.

Tóm tắt

Coccoloba uvifera (L.) L. is widely cultivated in coastal regions of Vietnam, but phytochemical data on Vietnamese-grown material remain limited. This study investigated the flavonoid constituents and antioxidant activity of C. uvifera leaves using a bioactivity-guided approach. The leaves were extracted with 80% ethanol and successively partitioned with n-hexane, chloroform, ethyl acetate, and water. Among the tested fractions, the ethyl acetate fraction showed the highest DPPH radical-scavenging activity and was selected for chromatographic isolation. Five flavonols were identified by MS and NMR analyses as quercetin, avicularin, quercitrin, isoquercitrin, and myricetin. The isolated compounds exhibited DPPH radical-scavenging activity with IC₅₀ values ranging from 2.12 to 3.94 µg/mL. These findings indicate that flavonols are important contributors to the antioxidant activity of C. uvifera leaves cultivated in Vietnam.