Morinols A-L, twelve novel sesquineolignans and neolignans with a new carbon skeleton from Morina chinensis

Two novel tetrahydropyran sesquineolignans with a new carbon skeleton, named morinols A (1) and B (2), and other ten novel neolignans, named morinols C-L (3-12), along with two known lignans, pinoresinol (13) and lariciresinol (14), have been isolated from the roots of Chinese medicinal herb, Morina chinensis. The structures of all of the compounds have been determined mainly on the basis of modern spectroscopic evidences (H-1 NMR, C-13 NMR, DEFT, H-1-H-1 COSY, NOESY, HSQC, HMBC and HRMS), as well as chemical transformation. The inhibitory effects of the isomers, morinols A (1) and B CZ), on cytokine production have been studied, the results indicated that morinol B (2) has more stronger activity than morinol A (1). Morinols B (2), E (5) and G (7) were verified should be enantiomeric natural products by means of MTPA and 2NMA. (C) 1999 Elsevier Science Ltd. All rights reserved.