New glucosyloxybenzyl 2R-benzylmalate derivatives from the undergrounds parts of Arundina graminifolia (Orchidaceae).

Phytochemical investigation of the underground part of the blossoming tropical orchid Arundina graminifolia led to the isolation of six new glucosyloxybenzyl 2R-benzylmalate derivatives named arundinosides L-Q (1-6) together with 5 known compounds arundinosides D-F, J and K (7-11). The structures of the isolated compounds were determined by extensive spectroscopic data analysis. The anti-α-glucosidase and antioxidant activities of the isolated compounds were determined. The result indicated that compounds 4-6 and 9 showed moderate to weak α-glucosidase inhibitory effects as well as moderate antioxidant effect.