Nature. 1979 May 31;279(5712):450-1. doi: 10.1038/279450a0.
SINGLET molecular oxygen is a very powerful oxidant. Its action is important in a variety of chemical and biological processes(1-4), for examples dye-sensitised photooxidation of lipids, proteins and nucleic acids(4), photodynamic inactivation of viruses(5) and cells(4), phototherapy of cancer(6,7), carcinogenesis(8), haemolysis of erythocytes(9), sensitisation of the human skin(4) and degradation of food(4). The methods used to detect singlet oxygen are unspecific, of low sensitivity or laborious. Photooxidation of 1,3-diphenylisobenzofuran seems to be the most widely used diagnostic test for (1)O(2). However, in the absence of additional control experiments this test does not prove the intermediacy of (1)O(2) (ref. 4) and 1,3-diphenylisobenzofuran has very low solubility and dimerises in aqueous solutions. Lion et al.(10) have proposed a new method to detect (1)O(2) involving the generation of stable nitroxide radicals when (1)O(2) reacts with the sterically hindered amine 2,2,6,6,-tetramethylpiperidin. When using this method to detect (1)O(2) in neutral aqueous solutions, we found no radical production. We report here our investigation of this problem, as it is biologically important to be able to detect (1)O(2) production in such solutions.
单线态分子氧是一种非常强的氧化剂。它的作用在各种化学和生物过程中都很重要(1-4)，例如染料敏化的脂质、蛋白质和核酸的光氧化(4)、病毒(5)和细胞(4)的光动力失活、癌症的光疗(6,7)、致癌作用(8)、红细胞的溶血(9)、人类皮肤的敏化(4)和食物的降解(4)。用于检测单线态氧的方法不具有特异性、灵敏度低或繁琐。1,3-二苯基异苯并呋喃的光氧化似乎是最广泛用于(1)O(2)的诊断测试。然而，在没有额外的对照实验的情况下，该测试并不能证明(1)O(2)的中间体(4)，并且 1,3-二苯基异苯并呋喃的溶解度非常低，并在水溶液中二聚化。Lion 等人(10)提出了一种新的方法来检测(1)O(2)，涉及当(1)O(2)与空间位阻胺 2,2,6,6-四甲基哌啶反应时生成稳定的氮氧化物自由基。当我们使用该方法在中性水溶液中检测(1)O(2)时，我们没有发现自由基的产生。我们在这里报告了对这个问题的研究，因为能够在这种溶液中检测(1)O(2)的产生在生物学上是很重要的。
