Effect of oxygen on spin-spin and spin-lattice relaxation in DOPA-melanin. Complexes with chloroquine and metal ions
Effect of oxygen on spin-spin and spin-lattice relaxation in DOPA-melanin. Complexes with chloroquine and metal ions
复制标题
氧对多巴黑色素自旋-自旋和自旋-晶格弛豫的影响。
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
T. Wilczok
中科院分区：
文献类型：
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作者：
B. Pilawa;M. Latocha;E. Buszman;T. Wilczok
对氯喹与 3,4-二羟基苯丙氨酸 (DOPA) 合成的黑色素复合物的电子顺磁共振 (EPR) 研究证实，ofo-半醌自由基在黑色素与药物结合过程中发挥着重要作用。氯喹会增加多巴黑色素中自由基的浓度。还证明氯喹与黑色素的结合可以被金属离子修饰。 Co2+ 离子减少 DOPA-黑色素和黑色素-氯喹复合物中自由基的浓度，Zn2+ 离子增加自由基的浓度。黑色素的自由基特性很大程度上取决于样品环境中氧气 (O2) 的存在。黑色素和氧分子的相互作用导致样品中自由基浓度降低和 EPR 线变窄。与真空样品相比，空气中黑色素样品的自旋-自旋和自旋-晶格弛豫时间值更高。建议将观察到的效果应用于血氧定量法。
Electron paramagnetic resonance (EPR) studies of complexes of chloroquine with melanin synthesized from 3,4-dihydroxyphenylalanine (DOPA) confirmed an important role ofo-semiquinone free radicals during the drug binding by melanin. Chloroquine increases free radical concentration in DOPA-melanin. It has been also demonstrated that chloroquine binding to melanin is modified by metal ions. Co2+ ions reduce and Zn2+ ions increase the concentration of free radicals in both DOPA-melanin and melanin-chloroquine complexes. Free radical properties of melanin strongly depend on the presence of oxygen (O2) in the environment of the sample. Interactions of melanin and oxygen molecules cause a decrease of the free radical concentration in the samples and a narrowing of the EPR lines. Higher values of both spin-spin and spin-lattice relaxation times were determined for melanin samples in air than for evacuated samples. Application of the observed effects in oximetry is suggested.