Enantiomeric diarylheptanoids from Ottelia acuminata var. acuminata and their α-glucosidase inhibitory activity

Abstract Otteacumienes G–K ( 1 – 5 ), five pairs of enantiomeric diarylheptanoids, along with one undescribed diarylheptanoid glycoside and one new lignan, were isolated from Ottelia acuminata var. acuminata . Compounds 1 – 5 were identified as five pairs of enantiomers and their structural configurations were determined through a combination of spectroscopic analysis, X-ray crystallography, and ECD calculation. Notably, compound 6 was the first diarylheptanoid glycoside isolated from this aquatic species, and its absolute configuration was unequivocally established through semi-synthesis. Biological evaluation demonstrated that compound 1 exhibited α -glucosidase inhibitory activity, with an inhibition ratio of 38.97% (acarbose as the positive control, inhibition ratio = 13.52%). Graphical abstract