EPR OF MELANIN AT W BAND

各种类型的黑色素（多巴，5-S-胱氨酸多巴，多巴胺，DHI） 在一定pH值范围内，用W带EPR研究了样品的电子顺磁共振（EPR）谱。 的 高频率下的分辨率大大提高， 不同黑色素的g-各向异性作为以下函数进行研究： 博士 在X波段具有基本相同光谱的黑色素可以 在W波段有区别。 预测MO理论帮助人们选择 在这些物种的假设结构之间。 不同 半醌阴离子自由基已经在不同的黑色素中被鉴定 在碱性条件下。 这些半醌自由基主要是 这是由于二羟基吲哚基团被很好地水合。 黑色素也 含有一组不是半醌的自由基， 半醌亚胺和pH值变化不大。这些自由基是 与微球的溶解或浓缩程度较低的部分相关， 聚合物的

Various types of melanin (DOPA, 5-S-cystienylDOPA, dopamine, DHI) at a range of sample pH values have been studied by W-band EPR. The greatly enhanced resolution at high frequency allows for the unique g-anisotropies of different melanins to be studied as a function of pH. Melanins which have essentially identical spectra at X-band can be distinguished at W-band. Predictive MO theory helps one to choose between postulated structures for these species. Different semiquinone anion radicals have been identified in different melanins under alkaline conditions. These semiquinone radicals are primarily due to dihydroxyindole groups that are well hydrated. Melanin also contains a set of free radicals which are not semiquinone or semiquinone imines and vary little with pH. These radicals are associated with the less solubilized or condensed portion of the polymer.