New Beta-Dihydroagarofuran Sesquiterpene Polyesters Isolated From The Root Bark Of Celastrus Angulatus

Three new ?-dihydroagarofuran sesquiterpene polyesters, angulatin O (1?,2?-difuroyloxy-8?-isobutanoyloxy-9?benzoyloxy-15-acetoxy-4?,6?-dihydroxy-?-dihydroagarofuran), angulatin Q (1?,6?,15-triacetoxy-2?,9?-difuroyloxy-4?-hydroxy-8?-isobutanoyloxy-?-dihydro-agarofuran), and angulatin R (1?,2?,6?,15-tetracetoxy-8?-isobutanoyloxy-9?-benzoyloxy-?-dihydroagarofuran), as well as six related and known compounds, ?-dihydroagarofuran sesquiterpene polyesters, were isolated from the root bark of Celastrus angulatus. Extensive spectroscopic studies were conducted to elucidate the structures of the new compounds. The IR, HRESI-MS, 1D, and 2D NMR techniques were used to characterise the compounds.