Combined MS/MS-NMR Annotation Guided Discovery of Iris lactea var. chinensis Seed as a Source of Viral Neuraminidase Inhibitory Polyphenols

Abstract

In this study, the chemical diversity of polyphenols inIris lacteavar. chinensisseeds was identified by combined MS/MS-NMR analysis. Based on the annotated chemical profile, the isolation of stilbene oligomers was conducted, and consequently, stilbene oligomers (1-10) were characterized. Of these, compounds1and2are previously undescribed stilbene dimer glycoside (1) and tetramer glycoside (2), respectively. Besides, to evaluate this plant seed as a rich source of stilbene oligomers, we quantified three stilbene oligomers ofI. lacteavar.chinensisseeds. The contents of three major stilbene oligomers-trans-epsilon-viniferin (3), vitisin A (6), and vitisin B (9)-inI. lacteavar.chinensisseeds were quantified as 2.32 (3), 4.95 (6), and 1.64 (9) mg/g dry weight (DW). All the isolated compounds were tested for their inhibitory activities against influenza neuraminidase. Compound10was found to be active with the half maximal inhibitory concentration (IC50) values at 4.76 mu M. Taken together, it is concluded thatI. lacteavar.chinensisseed is a valuable source of stilbene oligomers with a human health benefit.