Ring-B linked bidihydroflavonoids from Thuidium kanedae Sak

A new bidihydroflavonoid, thuidinin 1, together with 5 known compounds including one known biflavonoid 3′,3‴-binaringenin (2) and four other known natural products pentadecane (3), methyl β-orcinolarboxylate (4), β-sitosterol (5) and daucostenol (6), were isolated from leaves of Thuidium kanedae Sak. Their structures were established on the basis of 1D and 2D spectroscopic analysis. The absolute stereochemistry of compounds 1 and 2 was determined by CD spectra.