A new antioxidant from wild nutmeg

Nutmeg (Myristica fragans and Myristica argentea) is a spice widely used in food. Argenteane is a dilignan which has been isolated from nutmeg mace (the lace-like seed membrane of nutmeg). On the basis of the experimental measurements of the lipid peroxidation inhibition, argenteane appeared to be an antioxidant as powerful as vitamin E. The present joint experimental and theoretical study helped to understand the mechanism of action of this compound. The density functional theory (DFT) calculations of the O–H bond dissociation enthalpies (BDEs) correlated with the capacity to scavenge free radicals. We demonstrated that the central moiety is able to release one or two H atom(s) to the free radicals. This mechanism was confirmed by (i) the BDE calculations and (ii) the free radical-scavenging capacity measurements of two lignans and 3,3′-dimethoxy-1,1′-biphenyl-4,4′-diol (i.e., the argenteane central moiety). In addition to this active part, two lipophilic chains participate in the molecule’s capacity to react with the oxidative species generated in the membrane vicinity.