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, 2 R /2 S -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 H 2 O 2 -induced cytotoxicity with EA.hy926 cells were tested. The results showed that compounds 1 – 3 improved the survival of EA.hy926 cells after H 2 O 2 exposure at the tested concentrations. [ABSTRACT FROM AUTHOR]