Pavonin: A new five-membered lactone from Adenanthera pavonina linn. (Mimoaceae)

A new five-membered lactone named pavonin with an exo-cyclic double bond has been isolated from the methanol soluble part of Adenanthera pavonina Linn. belonging to the family Mimoaceae. The structure of pavonin has been established with the aid of spectroscopic techniques including decoupling and HMBC experiments.