Chemical constituents of Vietnamese mangrove Hibiscus tiliaceus with antioxidant and alpha-glucosidase inhibitory activity

Abstract

Using various chromatographic techniques, a total of 15 compounds, including one novel megastigmane named tiliaceic acid A (1) and 14 known compounds, were isolated from the traditional medicinal Vietnamese mangrove Hibiscus tiliaceus. Their structures were confirmed based on spectroscopic experiments including, UV, 1 D- and 2 D-NMR, HR-ESI-MS, and ECD analysis. The antioxidant and α-glucosidase inhibitory activities of the isolated compounds from H. tiliaceus were evaluated for the first time. Compound 2 showed strong α-glucosidase inhibitory activity with an IC₅₀ of 77.78 ± 1.00 μM compared with the positive control acarbose at 105.71 ± 2.29 μM.

Keywords: Hibiscus tiliaceus; Malvaceae; antioxidant; megastigmane; α-glucosidase.