Photodecomposition and Phototoxicity of Natural Retinoids

Photodecomposition and Phototoxicity of Natural Retinoids

Sunlight is a known human carcinogen. Many cosmetics contain retinoid-based compounds, such as retinyl palmitate (RP), either to protect the skin or to stimulate skin responses that will correct skin damaged by sunlight. However, little is known about the photodecomposition of some retinoids and the toxicity of these retinoids and their sunlight-induced photodecomposition products on skin. Thus...

On the Photodecomposition of C10N0

As its major removal process the photodissociat ion of a tmospheric C 1 0 N 0 2 in the ultraviolet is discussed. It has repeatedly been pointed out that significance should be at t r ibuted to the pathways of chlorine nitrate fo rmat ion and its destruction since this compound might be involved in the ozone depletion mechanism through both the C10x and N O x a tmospheric cycles. This communica ...

Separation of the natural retinoids by high-pressure liquid chromatography.

A reverse phase high-pressure liquid chromatography system for rapid separation of various retinoids (vitamin A and its analogs) with little or no degradation is described. This method permits detection of as little as 22 pmol of retinoic acid. The procedure has been applied to the study of retinoic acid metabolism in vitamin A-deficient hamsters.

Ocular phototoxicity.

The human eye is constantly exposed to sunlight and artificial lighting. Therefore the eye is exposed to UV-B (295-320 nm), UV-A (320-400 nm), and visible light (400-700 nm). Light is transmitted through the eye and then signals the brain directing both sight and circadian rhythm. Therefore light absorbed by the eye must be benign. Damage to the young and adult eye by intense ambient light is a...

Photodecomposition of Water Catalyzed by Zr- and Ti-MCM-41