2007 Volume 1 Issue 1 Pages 21-27
Eucommia bark contains lignans such as (+)-pinoresinol, (+)-1-hydroxypinoresinol, (+)-medioresinol, (+)-syringaresinol and (-)-olivil, and their glucosides. Each lignan was metabolized to enterodiol and enterolactone by human and rat intestinal bacteria. The structures of intermediate metabolites were elucidated and metabolic pathway was proposed. Each (-)-olivil and (+)-1-hydroxypinoresinol was converted to (-)-carinol, which to a new compound, (-)-2-hydroxyenterodiol, and successively to (-)-enterolactone by human intestinal bacteria. Oral administration of pinoresinol diglucoside in ovariectomized rats inhibited increase of body weight due to ovariectomy and exhibited a tendency to increase of uterine weight.