α-Glucosidase Inhibitory Xanthones from the Roots of Garcinia fusca.

Two new compounds, fuscaxanthones J (1) and K (2), together with eight known xanthones (3 - 10) were isolated from an ethyl acetate extract of the roots of Garcinia fusca. Their structures were determined using spectroscopic methods, mainly 1D- and 2D-NMR. α-Glucosidase inhibitory activity of the isolated compounds was evaluated and fuscaxanthone J (1) showed the most significant effect with an IC50 value of 8.3 ± 1.8 µm (compared with acarbose, IC50 = 214.5 ± 2.3 µm).