Morinols A and B, Two Novel Tetrahydropyran Sesquineolignans with a New Carbon Skeleton from Morina chinensis

Two sesquineolignans, each bearing a tetrahydropyran ring with a new carbon skeleton and named morinols A and B, have been isolated from the roots of a Chinese medicinal herb, Morina chinensis. Their structures have been determined on the basis of spectroscopic evidences, as well as a simple chemical transformation.