Department of Chemistry, University of York, Heslington, York YO10 5DD, UK.
The Procter & Gamble Company, Mason Business Center, 8700 Mason-Montgomery Road, Mason 45040, USA.
Free Radic Biol Med. 2018 Jun;121:20-25. doi: 10.1016/j.freeradbiomed.2018.04.548. Epub 2018 Apr 13.
EPR spectroscopy was used to monitor formation of free radicals in human hair upon UV irradiation. While the EPR spectra of brown hair were dominated by melanin signal, those of white hair were keratin-derived. The decay of UV induced keratin radicals was enhanced at increased ambient humidity. We argue that at higher humidity the swollen hair provides a more liquid-like environment, and higher molecular mobility in this environment leads to faster radical reactions. This interpretation is consistent with the increased UV-triggered protein damage in hair at high humidity as demonstrated by the protein loss, MALDI-TOF and FT-IR data.
电子顺磁共振（EPR）光谱被用于监测人类头发在紫外线照射下自由基的形成。在棕色头发的 EPR 光谱中，黑色素信号占主导地位，而在白发的 EPR 光谱中，角蛋白信号占主导地位。在增加的环境湿度下，紫外线诱导的角蛋白自由基的衰减得到增强。我们认为，在较高的湿度下，膨胀的头发提供了更类似液体的环境，并且在这种环境中更高的分子迁移率导致更快的自由基反应。这种解释与在较高湿度下头发中由于蛋白质损失、MALDI-TOF 和 FT-IR 数据所证明的增加的紫外线触发的蛋白质损伤一致。
