Flavonol Glycosides from the Flowering Plant Gaura biennis

Abstract

Phytochemical investigation of the whole plant of Gaura biennis led to isolation of eleven flavonol glycosides (1–11). Three of them (1–3) are new compounds and their structures were determined as quercetin 3-O-(2-O-α-rhamnopyranosyl-6-O-E-p-coumaroyl)-β-glucopyranoside (1), quercetin 3-O-(2-O-α-rhamnopyranosyl-6-O-Z-p-coumaroyl)-β-glucopyranoside (2), and kaempferol 3-O-(2-O-α-rhamnopyranosyl-6-O-E-p-coumaroyl)-β-glucopyranoside (3) by spectroscopic interpretations. The known compounds were kaempferol 3-O-glucopyranoside (4), kaempferol 3-O-(2-O-α-rhamnopyranosyl)-β-glucopyranoside (5), kaempferol 3-O-rutinoside (6), quercetin 3-neohesperidoside (7), quercetin 3-rutinoside (8), kaempferol 3-O-(2,6-di-O-rhamnosyl)-glucoside (9), quercetin 3-O-(2,6-di-O-rhamnopyranosyl)-glucopyranoside(10), and quercetin 3-O-(2-O-α-rhamnopyranosyl-6-O-galloyl)-β-glucopyranoside (11). Acknowledgments:The authors thank Dr. Bharathi Avula for recording HRESIMS spectra, Mr. Frank T. Wiggers for the assistance in obtaining NMR spectra, Mr. John Hester for repository management, and Dr. Wei Wang and Dr. Yanhong Wang for instrument assistance. This work was supported by the NIH, NIAID, Division of AIDS, Grant No. AI 27094, the USDA Agricultural Research Service Specific Cooperative Agreement No. 58-6408-2-0009, and China Scholarship Council.