CAJ | 학술논문

由于脂质过氧化反应(LPO)是导致人体疾病(如肝炎、肝硬化、动脉硬化、脑溢血等)的主要原因,而黄酮类化合物是一类很强的过氧化反应抑制剂,因此有必要研究其化学结构与过氧化反应的关系及其抗氧化机理.本文选择α-羟乙基过氧自由基为脂质过氧自由基的模拟物,采用脉冲辐解方法研究了乙醇溶液中4种典型的黄酮类化合物(槲皮素、芦丁、儿茶素以及黄岑甙)与α-羟乙基过氧自由基的反应动力学,测得其反应活性顺序为:芦丁>槲皮素>黄岑甙>儿茶素.同时以黄酮体和邻苯二酚为黄酮类化合物不同结构特征的模型化合物,用脉冲辐解法测得二者与α-羟乙基过氧自由基的反应速率常数分别为(1.7±0.1)×106和(2.9±0.1)×105 mol-1·dm3·s-1.实验结果表明,在黄酮类化合物与α-羟乙基过氧自由基的反应中, A环C5位的羟基, C环C2=C3或B-C环的大π键和B环邻二羟基共存时清除α-羟乙基过氧自由基活性最好,而且C环C2=C3或B-C环大π键的清除活性好于B环邻二羟基,同时C环是否含有C3-醣甙结构对清除作用没有明显影响.因此我们推测在黄酮类化合物抑制脂质过氧化反应过程中,起主要作用的是C环C2=C3或B-C环的大π键与脂质过氧自由基的双键加成反应.
유우지질과양화반응(LPO)시도치인체질병(여간염、간경화、동맥경화、뇌일혈등)적주요원인,이황동류화합물시일류흔강적과양화반응억제제,인차유필요연구기화학결구여과양화반응적관계급기항양화궤리.본문선택α-간을기과양자유기위지질과양자유기적모의물,채용맥충복해방법연구료을순용액중4충전형적황동류화합물(곡피소、호정、인다소이급황잠대)여α-간을기과양자유기적반응동역학,측득기반응활성순서위:호정>곡피소>황잠대>인다소.동시이황동체화린분이분위황동류화합물불동결구특정적모형화합물,용맥충복해법측득이자여α-간을기과양자유기적반응속솔상수분별위(1.7±0.1)×106화(2.9±0.1)×105 mol-1·dm3·s-1.실험결과표명,재황동류화합물여α-간을기과양자유기적반응중, A배C5위적간기, C배C2=C3혹B-C배적대π건화B배린이간기공존시청제α-간을기과양자유기활성최호,이차C배C2=C3혹B-C배대π건적청제활성호우B배린이간기,동시C배시부함유C3-당대결구대청제작용몰유명현영향.인차아문추측재황동류화합물억제지질과양화반응과정중,기주요작용적시C배C2=C3혹B-C배적대π건여지질과양자유기적쌍건가성반응.
Lipid peroxidation (LPO) plays an important role in many pathological processes (such as hepatitis, hepatic sclerosis, atherosclerosis, cerebral hemorrhage and so on), and flavonoids are considered to be effective LPO-inhibitors. Thus we investigated the relationship between the chemical structure of flavonoids and the LPO activity and the antioxidant mechanism of flavonoids. In this work,α-hydroxyl ethyl peroxyl radicals were produced from radiolysis of aerated ethanol to model lipid peroxyl radicals. By detecting the decay of α-hydroxyl ethyl peroxyl radicals in the presence of different concentrations of flavonoids using pulse radiolysis, the reaction rate constants ofα-hydroxyl ethyl peroxyl radicals with quercetin, rutin, catechin, and baicalin are determined for the first time. The antioxidant activity of these flavonoids decreases in the order: rutin>quercetin>baicalin>catechin. Flavone and pyrocatechol were used as model compounds for the different components in flavonoids and their reaction rate constants towardsα-hydroxyl ethyl peroxyl radicals were (1.7±0.1)×106 and (2.9±0.1)×105 mol-1·dm3· s-1, respectively. The effect of chemical structure on the scavenging activity towards α-hydroxyl ethyl peroxyl radicals was investigated. The coexistence of the C5-hydroxyl group in the A ring with the C2=C3 in the C ring or the conjugated double bond of the B-C ring and the catechol group in the B ring provides the best antioxidant activity. In addition, the C2=C3 in the C ring or the conjugated double bond of the B-C ring is more effective than the catechol group in the B ring, while the C3-rutinose in the C ring has no obvious effect. Therefore, we conclude that the addition reaction between double bonds with peroxyl radicals plays an important role in the antioxidant activity of flavonoids in LPO.