A new pair of enantiomeric lignans from the fruits of Morinda citrifolia and their absolute configuration

A new pair of sesamin-type lignan enantiomers (+/-)-morifolia A (1a/1b) together with eight known analogues (2-9) were isolated from the fruits of Morinda citrifolia. Their structures were established by spectroscopic data and the absolute configurations of 1a/1b were determined by ECD calculation. All compounds were examined for their inhibitory effects on the nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW 264.7 macrophages, and compounds 1a, 1b, 2-4 and 7-9 exhibited pronounced inhibition with IC50 values in the range of 1.97-8.01 (M, being more active than the positive control, quercetin (IC50=15.32 (M). [GRAPHICS] .