(--)-Catechin glycosides from Ulmus davidiana

Extensive chromatographic separation of the n-BuOH soluble fraction obtained from the stem and root barks of U. davidiana resulted in five hitherto unknown compounds together with a known one (-)-catechin 1. Structures of the five compounds were elucidated by chemical and spectroscopic analyses, to be (-)-catechin-7-O-gallate-5-O-(5″″-trans-caffeoyl)-β-D-apiofuranoside-3-O-β-D-apiofuranosyl-(1 → 2)-β-D-glucopyranoside 2, (-)-catechin-7-O-gallate-5-O-(5″″-trans-caffeoyl)-β-D-apiofuranoside-3-O-β-D-glucopyranoside 3, (-)-catechin-7-O-gallate-5-O-β-D-apiofuranoside-3-O-(2″-O-galloyl)-β-D-glucopyranoside 4, (-)-catechin-7-O-gallate-5-O-(5″″-trans-caffeoyl)-β-D-apiofuranoside 5, and (-)-catechin-7-O-gallate-5-O-(5″″-trans-feruloyl)-β-D-apiofuranoside 6.