Oleanane-type glycosides from the roots of Weigela florida "rumba" and evaluation of their antibody recognition.

ABSTRACT

Three triterpene glycosides were isolated from the roots of Weigela florida "rumba" (Bunge) A. DC. two previously undescribed 3-O-ß-d-xylopyranosyl-(1→2)-[ß-d-xylopyranosyl-(1→4)]-ß-d-xylopyranosyl-(1→4)-ß-d-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-l-arabinopyranosyloleanolic acid (1) and 3-O-ß-d-xylopyranosyl-(1→2)-[ß-d-glucopyranosyl-(1→4)]-ß-d-xylopyranosyl-(1→4)-ß-d-xylopyranosyl-(1→3)-α-l-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyloleanolic acid (2), and one isolated for the first time from a natural source 3-O-ß-d-xylopyranosyl-(1→3)-α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranosyloleanolic acid (3). Their structures were elucidated mainly by 2D NMR spectroscopic analysis (COSY, TOCSY, NOESY, HSQC, HMBC) and mass spectrometry. Compounds 2 and 3 were further evaluated as antigens in enzyme-linked immunosorbent assay (ELISA) to recognize IgM antibodies in multiple sclerosis (MS) patients' sera.