Three pairs of diastereoisomeric flavanone glycosides from Viscum articulatum.

Phytochemical examination of the leaves and stems of Viscum articulatum resulted in the isolation of three pairs of new flavanone glycosides, 2R/2S-viscarticulide A-C (1a/1b-3a/3b), together with eight known compounds (7-14). Their structures were established by extensive spectroscopic data analyses. The diastereoisomers were separated by HPLC on a chiral phase and the absolute configuration at C-2 was determined by circular dichroism (CD) spectra. The protective effects of compounds 1-3 against H2O2-induced cytotoxicity with EA.hy926 cells were tested. The results showed that compounds 1-3 improved the survival of EA.hy926 cells after H2O2 exposure at the tested concentrations.