Exposure of vitamins to UVB and UVA radiation generates singlet oxygen
Exposure of vitamins to UVB and UVA radiation generates singlet oxygen
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DOI：
10.1039/c3pp50413a
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发表时间：
2014-01-01
影响因子：
3.1
通讯作者：
Baeumler, Wolfgang
中科院分区：
文献类型：
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作者：
Knak, Alena;Regensburger, Johannes;Baeumler, Wolfgang
紫外线辐射对组织的有害影响通常归因于不同的机制。 DNA 等细胞成分吸收 UVB 辐射会引起光化学反应。维生素等内源性光敏剂吸收 UVA 辐射，通过光敏反应产生单线态氧。我们研究了可能与紫外线介导的细胞组织损伤有关的两种进一步机制。首先，UVB辐射和维生素也会产生单线态氧。其次，UVB 辐射可能会改变维生素的化学结构，从而可能改变此类内源性光敏剂在 UVA 介导机制中的作用。使用单色 UVB（308 nm）或 UVA（330、355 或 370 nm）辐射对溶液中的维生素进行照射。单线态氧通过 1270 nm 处的发光直接检测和定量。所有研究的分子均产生单线态氧，其量子产率范围为 0.007（维生素 D-3）至 0.64（烟酰胺），与激发波长无关。此外，用 UVB 预先照射维生素会改变其在 UVB 和 UVA 光谱范围内的吸收。随后，维生素 E 和维生素 K-1 等分子通常在 UVA 中不会产生单线态氧，现在当暴露于 355 nm 的 UVA 时会产生单线态氧。在体外实验中使用 UVA 和 UVB 进行串行或并行照射时，不同紫外线源的相互作用是不可避免的。这些结果对于体内 UVA 和 UVB 的平行照射特别重要。 g。当皮肤暴露在太阳辐射下时。
Deleterious effects of UV radiation in tissue are usually attributed to different mechanisms. Absorption of UVB radiation in cell constituents like DNA causes photochemical reactions. Absorption of UVA radiation in endogenous photosensitizers like vitamins generates singlet oxygen via photosensitized reactions. We investigated two further mechanisms that might be involved in UV mediated cell tissue damage. Firstly, UVB radiation and vitamins also generate singlet oxygen. Secondly, UVB radiation may change the chemical structure of vitamins that may change the role of such endogenous photosensitizers in UVA mediated mechanisms. Vitamins were irradiated in solution using monochromatic UVB (308 nm) or UVA (330, 355, or 370 nm) radiation. Singlet oxygen was directly detected and quantified by its luminescence at 1270 nm. All investigated molecules generated singlet oxygen with a quantum yield ranging from 0.007 (vitamin D-3) to 0.64 (nicotinamide) independent of the excitation wavelength. Moreover, pre-irradiation of vitamins with UVB changed their absorption in the UVB and UVA spectral range. Subsequently, molecules such as vitamin E and vitamin K-1, which normally exhibit no singlet oxygen generation in the UVA, now produce singlet oxygen when exposed to UVA at 355 nm. This interplay of different UV sources is inevitable when applying serial or parallel irradiation with UVA and UVB in experiments in vitro. These results should be of particular importance for parallel irradiation with UVA and UVB in vivo, e. g. when exposing the skin to solar radiation.