Sesquiterpenes from the rhizome of Curcuma longa with inhibitory activity on superoxide generation and elastase release by neutrophils

Abstract Six new sesquiterpenes, curculonone A ( 1 ), curculonone B ( 2 ), curculonone C ( 3 ), curculonone D ( 4 ), 6α-hydroxycurcumanolide A ( 5 ), and 1,10-dehydro-10-deoxy-9-oxozedoarondiol ( 6 ), have been isolated from the rhizome of Curcuma longa , together with 19 known compounds. The structures of these new compounds were determined through spectroscopic and MS analyses. Compounds 1 , 2 , 5 , 12 , 15 , 16 , and 23 exhibited inhibition (IC 50  ⩽ 18.22 μM) of superoxide anion generation by human neutrophils in response to formyl-L-methionyl-L-leucyl-L-phenylalanine/cytochalasin B (fMLP/CB). Compounds 5 , 12–16 , and 23 inhibited fMLP/CB-induced elastase release with IC 50 values ⩽ 14.28 μM.