Chemical constituents of the rhizomes of Coeloglossum viride var. bracteatum

Abstract

Seven new compounds, named coelovirins A–G (1–7), along with fourteen known constituents were isolated from the rhizomes of Coeloglossom viride var. bracteatum (Orchidaceae). On the basis of chemical and spectroscopic methods, including 2D-NMR techniques, the structures of new compounds were elucidated as 1-(4-β-d-glucopyranosyloxybenzyl)-(2R,3S)-2-isobutyltartrate (1), 4-(4-β-d-glucopyranosyloxybenzyl)-(2R,3S)-2-isobutyltartrate (2), 1-(4-β-d-glucopyranosyloxybenzyl)-(2R,3S)-2-β-d-glucopyranosyl-2-isobutyltartrate (3), 4-(4-β-d-glucopyranosyloxybenzyl)-(2R,3S)-2-β-d-glucopyranosyl-2-isobutyltartrate (4), (2R,3S)-2-β-d-glucopyranosyl-2-isobutyltartaric acid (5), bis(4-β-d-glucopyranosyloxybenzyl)-(2R,3S)-2-[β-d-glucopyranosyl-(1→4)-β-d-glucopyranosyl]-2-isobutyltartrate (6) and bis(4-β-d-glucopyranosyloxybenzyl)-(2R)-2-[β-d-glucopyranosyl-(1→4)-β-d-glucopyranosyl]-2-isobutylmalate (7). The known compounds are 4-hydroxybenzaldehyde, 4-hydroxybenzyl alcohol, 4,4′-dihydroxydibenzyl ether, 4,4′-dihydroxydiphenylmethane, 4-(4-hydroxybenzyloxy)benzyl alcohol, gastrodin, quercetin-3,7-diglucoside, thymidine, loroglossin, militarine, dactylorhin A, dactylorhin B, β-sitosterol and daucosterol.

Keywords:

• Coeloglossom viride var. bracteatum
• Coelovirins A–G
• Mono- and bis-(4-O-β-D-glucopyranosylbenzyl) tartrate and malate derivatives

Acknowledgements

The authors are grateful to Professor A. Zeper for mass spectra measurements. We also thank Mr W.-Y. He for his assistance in obtaining the 2D-NMR spectra. This work was supported by the Science and Technology Committee of Beijing District (Grant No. 9550214900).