Four new sesquiterpene polyol esters from Celastrus angulatus

Abstract Celastrus species, such as Celastrus angulatus , has been demonstrated to be very rich in natural sesquiterpene polyol esters sharing the β -dihydroagarofuran skeleton, some of which showed various biological activities. In this paper, four new sesquiterpene polyol esters, named as angulatins K-N ( 1 – 4 ), along with three known ones, 1 β -acetoxy-9 β -benzoxy-4α, 6α-dihydroxy-8α, 15-diisobutanoyloxy-2 β -(α-methyl)-butanoyloxy- β -dihydroagarofuran, angulatin A, and celangulin III, were isolated from the root bark of C. angulatus . The structures of the new compounds were elucidated by extensive spectroscopic methods, mainly including HR-MS and 1D and 2D NMR techniques.