Two new isobutyltartrate monoesters, coelovirin A (1) and B (2), were isolated from the rhizomes of Coeloglossum viride (L.) Hartm. var. bracteatum (Willd.) Richter (Orchidaceae). Their structures were elucidated as (2R, 3S)-2-isobutyltartrate-1-(4-(-D-glucopyranosyloxybenzyl) ester 1 and (2R, 3S)-2-isobutyltartrate-4-(4-(-D-glucopyranosyloxybenzyl) ester 2 on the basis of physical constants and spectroscopic methods including 2D NMR techniques.