Constituents of a Fern, Davallia mariesii Moore. IV. Isolation and Structures of a Novel Norcarotane Sesquiterpene Glycoside, a Chromone Glucuronide, and Two Epicatechin Glycosides.

Three new compounds, (-)-epicatechin-5-O-β-D-glulcopyranodside (1), 5, 7-dihydroxychromone-7-O-β-D-glucuronide methyl ester (6), and a novel norcarotane sesquiterpene glucoside named marioside (7), have been isolated from the rhizomes of Davallia mariesii MOORE together with five known compounds, (-)-epicatechin-3-O-β-D-allopyranoside (2), coumaric acid-4-O-β-D-glucopyranoside (3), caffeic acid-4-O-β-D-glucopyranoside (4), vanillic acid-4-O-β-D-glucopyranoside (5), and L-tryptophan (8). The structures of the new compounds (1, 6, and 7) were determined by means of spectroscopic methods including two-dimensional nuclear magnetic resonance techniques.