Superoxidation of BisretinoidsWe thank the National Institutes of Health (GM[thinsp]0365[thinsp]64 to K.N.) and the National Science Foundation (CHE[thinsp]04-10[thinsp]655, N.J.T.) for financial support

In addition to their role in vision, retinoids, for example, 1a–k and their derivatives, have been found to affect fetal development, cell differentiation, metabolism, and organ and cell regulation. They also provide lead structures for various anticancer, anti-inflammatory, and antibacterial drugs. In plants and food, they act as hormones, pigments, flavors, aromas, and as defense substances. The polyenes 1a–k react readily with singlet oxygen. Reactions with oxygen can be initiated by light, in the presence or absence of a photosensitizer, or by autoxidation. The oxidized products often show biological activity and are responsible for various aromas and tastes of food. 3] Identification of the oxygenated products is complicated by the fact that the initial species are reactive dioxetanes, peroxides,