Structure-guided identification of novel phenolic and phenolic amide allosides from the rhizomes of cimicifuga heracleifolia

Abstract

Two phenolic allopyranosides and two phenolic amide allopyranosides, along with eight known phenolic compounds, including cimicifugic acids, shomaside B, fukiic acid, isoferulic acid, and piscidic acid, were isolated from the n-butanolic extract of rhizomes of Cimicifuga heracleifolia. On-line spectroscopic data for UV, NMR, and MS from a combination of LC-NMR and LC-MS techniques directly and rapidly provided sufficient structural information to identify and confirm all the structures of major phenolic compounds in the extract, in addition to their HPLC profiles. This combined analytic information was then used as a dereplication tool for structure-guided screening in order to isolate unknown phenolic compounds in the extract. Successive fractionation and purification using semi-preparative HPLC acquired four unknown allopyranosides, and their structures were identified as cis-ferulic acid 4-O-β-D- allopyranoside, trans-ferulic acid 4-O-β-D-allopyranoside, trans-feruloyltyramine 4-O-β-D-allopyranoside, and trans-feruloyl-(3-O- methyl)dopamine 4-O-β-D-allopyranoside, based on a subsequent spectroscopic interpretation.