Two New Tartrate Derivative Glucosides from Coeloglossum viride （L.） Hartm. var. bracteatum （Willd.） Richter

Two new tartrate derivative glucosides, coelovirin C (1) and D (2), were isolated from rhizomes of Coeloglossum viride ( L.) Hartm. var. bracteatum ( Willd.) Richter (Orchidaceae). Their structures were elucidated as (2R, 3S)-2-β-D-glucopyranosyl-2-isobutyltartrate-1-(4-β-D- glucopyranosyloxybenzyl) ester 1 and (2R, 3S)-2-β-D-glucopyranosyl-2-isobutyltartrate-4-(4-β-D- glucopyranosyloxybenzyl) ester 2 by means of chemical and spectroscopic methods.