C-glycosylflavone with rotational isomers from Vaccaria hispanica (Miller) Rauschert seeds. (March 2017)

• Record Type: Journal Article
• Authors: Zhou, Guohong; Wu, Hongwei; Wang, Ting; Guo, Rixin; Xu, Jing; Zhang, Qiong; Tang, Liying; Wang, Zhuju
• Is Part Of: Phytochemistry letters. Volume 19(2017:Mar.)
• Page Start: 241
• Page End: 247
• Publication Date: 2017-03
• Subjects: Vaccaria hispanica -- C-glycosylflavone -- Rotational isomer -- Vaccarin E -- Vaccarin F; Botanical chemistry -- Periodicals; Chimie végétale -- Périodiques; 572.205
• DOI: 10.1016/j.phytol.2017.01.017
• Languages: English
• ISSNs: 1874-3900

Abstract

Graphical abstract: Highlights: Five C-glycosylflavonoids were isolated from the seeds of Vaccaria hispanica . The structure of "vaccarin" is revised. Two new C-glycosylflavonoids were isolated. Their NMR spectrums showed separate signals because of the rotational isomers. Abstract: Five C-glycosylflavone were isolated from Vaccaria hispanica (Miller) Rauschert seeds. Their NMR spectra showed separate signals because of the existence of rotational isomers, which is an unusual phenomenon. The spectroscopic data revealed that compounds1 –5 were identified as apigenin 6- C -[ α -l -arabinopyranosyl-(1′′′→2′′)- β -d -glucopyranosyl]-7- O - β -d -glucopyranoside (1 ), apigenin 6- C -[ α -l -arabinopyranosyl-(1′′′→2′′)- β -d -glucopyranosyl]-7- O -(6′′′′- O -dihydroferuloyl)- β -d -glucopyranoside (2 ), apigenin 6- C - β -d -glucopyranosyl-7- O -(6′′′- O -dihydroferuloyl)- β -d -glucopyranoside (3 ) and isovitexin-2′′- O -arabinoside (4 ) and saponarin (5 ), respectively. The structure of 'vaccarin' was revised to apigenin 6- C -[ α -l -arabinopyranosyl-(1′′′→2′′)- β -d -glucopyranosyl]-7- O - β -d -glucopyranoside and consequently1 should be named 'vaccarin'. Among the isolated compounds, 2 and3 are new and named vaccarin E and vaccarin F, respectively.