The present work was launched to study the chemical constituents from fermented Noni juice. Ten compounds were isolated by using silicagel,Sephadex LH-20 and pre-HPLC. The structures of these compounds were identified by 1D and 2D NMR. Their structures were established as norimester( 1),cyclo( R-Pro-S-Phe)( 2),cyclo-( L-Pro-L-Leu)( 3),trans-cyclo-( D-tryptophanyl-Ltyrosyl)( 4),cyclo( L-Trp-N-methyl-L-Ala-)( 5),4-allyl-2-hydroxyphenyl 1-O-β-D-apiosyl-( 1 → 6)-β-D-glucopyranoside( 6),2-methoxy-4-vinylphenyl β-D-apiofuranosyl-( 1→6)-β-D-glucopyranoside( 7),( +)-lirioresinol A( 8),( ±)-syringaresinol( 9),and2-formyl-1 H-pyrrole-1-butanoic acid( 10). All compounds were tested for their antibacterial activity and α-glucosidase inhibitory activity. Compound 1 was a new compound. All compounds were isolated from fermented Noni juice for the first time. Compound 1 showed significant inhibitory activity against α-glucosidase [IC50 value of( 4. 22±0. 03) μmol·L-1].
Keywords: chemical constituents; fermented Noni juice; structural identification; α-glucosidase activity.