Protective effects of recently synthesized dehydrozingerone, (2) (which is an half molecule of curcumin) and dimer of dehydrozingerone, D1(OH)2, as individual compounds -tocopherol (TOH) and/or ascorbyl palmitate (AscPH) were studied during bulk lipid autoxidation at 80oC. The highest oxidation stability of lipid substrate in presence of individual compounds was found for TOH, followed by D1(OH)2 and (2), determined from the main kinetic parameters (antioxidant efficiency, reactivity and capacity). AscPH did not show any protective effect. Synergism was obtained for the binary mixtures of (TOH+AscPH), 42.4 %; (2+TOH), 32.4 % and (2+AscPH), 35.6 %; and for the ternary mixture of (2+TOH+AscPH), 28.7 %. Different protective effects observed were explained on the basis of results of TOH regeneration and its content determined by HPLC. A further study compared the ability of monomers related to curcumin (1): dehydrozingerone (2), zingerone (3), (2Z,5E)-ethyl 2-hydroxy-6-(4-hydroxy-3-methoxyphenyl)-4-oxohexa-2,5-dienoate (4), ferulic acid (5) and their corresponding dimers 6-9 to scavenge different peroxide radicals and to act as chain-breaking antioxidants. Four models were applied to study the antioxidant potential of the compounds. The dimers and the monomers demonstrated higher activity than Trolox (10) in water medium (model 3). A comparison of the studied compounds with DL-?-tocopherol (11), Trolox 10 and curcumin 1 is made. All dimers are characterized through lower bond dissociation enthalpies (BDEs) than their monomers (model 4) which qualitatively supports the experimental results. The antioxidant binary and ternary mixtures studied can be used as functional components of foods with health-promoting effect especially when lipid-soluble antioxidants or modification of fatty acid metabolism by phenols in meat-eating animals are required. Studies on antioxidant potential of monomer and dimers of curcumin provide information on the role of the curcumin structure.
PROTECTIVE EFFECTS OF EQUIMOLAR MIXTURES OF MONOMER AND DIMER OF DEHYDROZINGERONE WITH -TOCOPHEROL AND/OR ASCORBYL PALMITATE DURING BULK LIPID AUTOXIDATION AND STUDIES OF ANTIOXIDANT POTENTIAL OF CURCUMIN- RELATED COMPOUNDS
D Fabbri;M A Dettori;
2016
Abstract
Protective effects of recently synthesized dehydrozingerone, (2) (which is an half molecule of curcumin) and dimer of dehydrozingerone, D1(OH)2, as individual compounds -tocopherol (TOH) and/or ascorbyl palmitate (AscPH) were studied during bulk lipid autoxidation at 80oC. The highest oxidation stability of lipid substrate in presence of individual compounds was found for TOH, followed by D1(OH)2 and (2), determined from the main kinetic parameters (antioxidant efficiency, reactivity and capacity). AscPH did not show any protective effect. Synergism was obtained for the binary mixtures of (TOH+AscPH), 42.4 %; (2+TOH), 32.4 % and (2+AscPH), 35.6 %; and for the ternary mixture of (2+TOH+AscPH), 28.7 %. Different protective effects observed were explained on the basis of results of TOH regeneration and its content determined by HPLC. A further study compared the ability of monomers related to curcumin (1): dehydrozingerone (2), zingerone (3), (2Z,5E)-ethyl 2-hydroxy-6-(4-hydroxy-3-methoxyphenyl)-4-oxohexa-2,5-dienoate (4), ferulic acid (5) and their corresponding dimers 6-9 to scavenge different peroxide radicals and to act as chain-breaking antioxidants. Four models were applied to study the antioxidant potential of the compounds. The dimers and the monomers demonstrated higher activity than Trolox (10) in water medium (model 3). A comparison of the studied compounds with DL-?-tocopherol (11), Trolox 10 and curcumin 1 is made. All dimers are characterized through lower bond dissociation enthalpies (BDEs) than their monomers (model 4) which qualitatively supports the experimental results. The antioxidant binary and ternary mixtures studied can be used as functional components of foods with health-promoting effect especially when lipid-soluble antioxidants or modification of fatty acid metabolism by phenols in meat-eating animals are required. Studies on antioxidant potential of monomer and dimers of curcumin provide information on the role of the curcumin structure.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
