[The constituents of Taxillus kaempferi and the host, Pinus thunbergii. I. Catechins and flavones of Taxillus kaempferi].

Four flavonoid compounds, avicularin (1), hyperin (2), quercitrin (3), taxillusin (4), were isolated from leaves of Taxillus kaempferi, and three catechin compounds, (+)-catechin (6), procyanidin B-1 (7), procyanidin B-3 (8), showing a reddish purple color on the reaction with Ehrlich reagent, were also isolated from the stems. Each of these seven isolated compounds were identified by comparing the spectral data with those of the references. Compound 8 was examined to substantiate the stereochemical configurations of conformer, a and b in the detailed 1H-nuclear magnetic resonance (1H-NMR) spectrum using the nuclear Overhauser effect (NOE) difference spectroscopy and spin decoupling experiment in the acetone-d6 solution.