Lignans from the Bark of Magnolia kobus

Abstract

The Et2O-soluble fraction from the bark of Magnolia kobus led to the isolation of two new lignans, (+)-(7 alpha,7'alpha,8 alpha,8'alpha)-3',4,4'.5,5'-pentamethoxy-7,9':7',9-diepoxylignan-3ol (1) and (+)-(7 alpha,7'alpha,8 alpha,8'alpha)-4,5-dimethoxy-3',4'- (methylenedioxy)-7,9':7',9-diepoxylignan-3-ol (2), along with five known lignans 3-7. Their structures were established on the basis of various spectroscopic analyses including 1D-(H-1, C-13, and DEPT) and 2D-NMR (COSY, NOESY, HMQC, and HMBC) and by comparison of their spectral data with those of related compounds.