Antioxidant Activity Of Chlorogenic Acids And Homologous Chlorogenic Acids For The Search For The Synergistic Antioxidant Mechanism

Industrial synthetic antioxidants such as BHT, BHA and BHQ has a certain potential side effects and the risk of cancer, and extensive use of natural antioxidants can cause in vivo tumor metastasis, increase the risk of cancer, disturb cell signal transduction of stem cells and toxic and side effect for neural stem cells, so reasonable and scientific use of antioxidants, and the controllability of antioxidant activity was the development direction of natural antioxidants in the future research field.Six kinds of CQAs isomers existing in coffee bean, honeysuckle, Eucommia ulmoides was chosen as the raw material using ABTS radical scavenging activity, FRAP ferrous ion reduction activity and ?-carotene bleaching inhibition ability for the research of the antioxidant activity in vivo for CQAs isomer monomer and the binary compounding systems of six kinds of CQAs isomers, and the mechanism of synergistic antioxidant was demonstrated through Cyclic voltammetry, the oil-water partition coefficient (log P), XRD, FT-IR and CD. The main conclusions are as follows:(1) System pH and phenolic hydroxyl number had a significant impact on the ABTS radical scavenging activity of chlorogenic acids isomers monomer, the significant level order was of phenolic hydroxyl number> system pH; System pH, reaction temperature and phenolic hydroxyl number had a significant impact on the FRAP ferrous ions reducing ability of chlorogenic acids isomers monomer, the significant level order was of phenolic hydroxyl number> reaction temperature> system pH; Compounding proportion and the oil-water partition coefficient difference of the binary compounding system of CQAs had a significant impact on the synergy degree of ABTS radical scavenging activity of the binary compounding system of CQAs, the significant level order was of compounding proportion> the oil-water partition coefficient difference; The difference of CQAs IC50 had a significant impact on the synergy degree of FRAP ferrous ion reducing ability of the binary compounding system of CQA+DICQA, Compounding proportion had a significant impact on the synergy degree of FRAP ferrous ion reducing ability of the binary compounding system of DICQAs; The oil-water partition coefficient difference of the binary compounding system of CQAs had a significant impact on the P-carotene bleaching inhibition ability of the binary compounding system of CQAs, the significant level order was of the oil-water partition coefficient difference of the binary compounding system> compounding proportion> the difference of CQAs IC50.(2) Oxidative coupling is the cause of synergistic antioxidant of chlorogenic acids in the emulsion system; In the experiments of ABTS radical scavenging activity and ?-carotene bleaching inhibition ability, the mechanism of synergistic antioxidant was the regeneration effect of CQAs and the dimerization reaction of CQAs semi-quinone intermediates for the phenolic hydroxyl regeneration; In the ferrous ions active experiment, the transferring charge cannot fully characterized the ferrous ion reduction activity of combined system.(3) The bigger difference of the antioxidant activity between CQAs molecular, the better synergy effect of ABTS radical scavenging activity of the binary compounding system of CQAs when the oil-water partition coefficient difference was fixed at 0.13, the binary compounding system of CQAs existed the certain crystal structure; Heavily acidic system seriously interfered the synergy effect of FRAP ferrous ion reducing ability of the binary compounding system between CQAs, leading to the disappearance of the interface effect; The bigger oil-water partition coefficient difference of the binary compounding system between CQAs and the greater antioxidant activity of CQAs molecular, the better synergy degree of ?-carotene bleaching inhibition ability, there does not exist self-assembly property between CQAs molecular.