β-胡萝卜素和α-生育酚协同抗氧化作用的微环境效应

Microenvironmental Effect in the Synergistic Antioxidation of β-Carotene and α-Tocopherol

分别用水溶性和脂溶性的偶氮引发剂2，2＇－偶氮二（2－眯基丙烷）二盐酸盐（AAPH）和连二次硝酸二叔丁酯（DBHN）引发亚油酸的过氧化，用氧气吸收法研究了β-胡萝卜素（β－C）和α-生育酚（VE）在负离子胶束十二烷基硫酸钠（SDS）、非离子胶束辛基苯基聚氧乙烯醚（TritonX－100）和正离子胶束十六烷基三甲基溴化铵（CTAB）中对亚油酸自动氧化的抗氧化和协同抗氧化作用．发现它们的抗氧化活性强烈地依赖于介质的微观环境及引发剂的亲脂性．β-C仅在SDS胶束中对DBHN引发的亚油酸过氧化有明显的抗氧化作用，但在SDS和TritonX－100中β-C可以和VE协同作用，显著加强VE对AAPH和DBHN引发的亚油酸过氧化的抑制作用．讨论了抗氧化活性与介质微环境的关系．

The antioxidation and antioxidant synergism of β-carotene(β-C) and α-tocopherol(VE) against free radical initiated peroxidation of linoleic acid have been studied by use ofoxygen uptake method in anionic , non-ionic and.cationic micelles, i. e., sodium dodecylsulfate (SDS), polyoxyethylene diisobutylphenol(Triton X-100) and cetyltrimethylammoniumbromide (CTAB), respectively. The peroxidation was initiated by an azo-initiator, eitherwater-soluble 2, 2' -azobis (2-amidinopropane) dihydrochloride(AAPH ) or oil-soluble di-tert-butyl hyponitrite(DBHN). It was found that the antioxidant activity depends significantly onthe microenvironment of the reaction medium and the lipophilicity of the initiator. Althoughβ-carotene alone shows relatively weak antioxidant activity only in case of the DBHN-initiated peroxidastion of linoleic acid in SDS micelle,it works very well synergistically with VE tosignificantly enhance the inhibition effect of VE for either AAPH and DBHN-initiated peroxi-dation of linoleic acid in SDS and Triton X-100 micelles. The relationship between theantioxidant activity and the microenvironment is discussed.