Studies on the Chemical Constituents from the Seeds of Noni and Their Anti-inflammatory Bioactivity
A new sesquineolignan moricitan A(1),a new natural product 4-methoxy isoamericanin A(2),a new anthraqui-none 1,3-dihydroxy-2,5-dimethoxy-6-(methoxymethyl)anthracene-9,10-dione(7),and seven known compounds 3~6 and 8~10 were obtained from the seeds of Noni.The structures were elucidated using comprehensive spectroscopic methods,and the absolute configuration of 1 was established based on quantum-chemical electronic circular dichroism calculations.The inhibi-tory activity of all the compounds on NO production in lipopolysaccharide-induced(LPS)mouse leukemia cells of monocyte macrophage(RAW 264.7)cells was evaluated.Compound 1 and 9'-ethyl americanol A(3)exhibited stronger anti-inflam-matory activity in vitro with IC50 values of(2.52±0.22)and(5.46±0.89)μmol/L to that of dexamethasone[IC50=(65.39± 1.02)μmol/L],respectively.