Chemical constituents and biological activities of the leaves of Adinandra megaphylla

A new cyclobutane derivative 3-(2-butoxy-3-caffeoyl-1-hydroxycyclobutyl)− 3-hydroxypropanoic acid named as debutyldorycnic acid (1), and a new flavonoid glycoside named as adinanquercetiside (2), together with thirteen known compounds (3-15) were isolated from leaves of Adinandra megaphylla Hu. Their chemical structures were elucidated on the basis of spectroscopic evidence. In the α-glucosidase activity evaluation, compounds 4, 5 and 7 significantly inhibited enzyme activity with IC50 values ranging from 13.67 ± 0.42 μg/mL to 27.52 ± 0.51 μg/mL.