Two new phenolic compounds from the seeds of Machilus yunnanensis

Chemical constituents investigation on the seeds of Machilus yunnanensis led to two new phenolic compounds 8-O-acetyl-phenylethanoid-4-O-β-D-glucopyranoside (1) and (E)-2,3-bis(4-hydroxyphenyl)acrylaldehyde (2), together with 16 known compounds. Their structures were elucidated on the basis of spectroscopic data analysis (IR, MS, 1D, and 2D NMR). Meanwhile, compounds 1–3, 6–13, 17, and 18 were evaluated for vasorelaxant effects on the rat endothelium-intact thoracic aorta rings precontracted with phenylephrine (PE) or KCl. The bioassay results showed that compound 17 had significant vasorelaxant effect on the endothelium-intact thoracic aorta rings precontracted with KCl.