New Benzoyl Glucosides and Cytotoxic Pterosin Sesquiterpenes from Pteris ensiformis Burm.

Abstract
Three new compounds: 2R,3R-pterosin L 3-O-β-D-glucopyranoside (1), β-Dxylopyranosyl(1→2)-7-O-benzoyl-β-D-glucopyranoside (2) and 4-O-benzoyl-β-D-xylopyranosyl(1→2)-7-O-benzoyl-β-D-glucopyranoside (3), together with nine knowncompounds, were isolated from the ethyl acetate extract of Pteris ensiformis. 5-[2-Hydroxyethylidene]-2(5H)-furanone (4), which had been synthesized, was isolated fromnatural sources for the first time. The structures of all isolated compounds were determinedon the basis of mass and spectroscopic evidence. Compound 1 and pterosin B (5) showcytotoxicity against HL 60 cells (human leukemia) with the IC50 values of 3.7 and 8.7μg/mL, respectively.