Four Undescribed Stilbenoid Derivatives from the Aerial Parts of Dendrobium officinale with their α‐Glucosidase and α‐Amylase Inhibitory Activity

Abstract In this study, four undescribed bibenzyl derivatives ( 1 – 4 ), together with seven known compounds ( 5 – 11 ) were isolated from the aerial parts of Dendrobium officinale . Their chemical structures were determined to be (7’ S ,8’ S ) ‐9′′‐acetyldendrocandin U ( 1 ), (7’ S ,8’ S ) ‐4′‐methoxydendrocandin T ( 2 ), (7’ R ,8’ S ) ‐dendrocandin B ( 3 ), (1 S ,2 R ) ‐5′′′‐methoxydendrofindlaphenol C ( 4 ) by analyzing of the spectroscopic data including HR‐ESI‐MS, 1D‐, and 2D‐NMR spectra. The absolute configurations of compounds 1 – 4 were determined by the electronic circular dichroism (ECD) spectra. Compounds 1 – 3 , 5 , 10 and 11 inhibited α ‐glucosidase with the IC 50 values ranging from 56.3 to 165.3 μM, compounds 1 – 3 , 5 , 7 – 10 inhibited α ‐amylase with the IC 50 values ranging from 65.2 to 177.6 μM.