The influence of temperature on photodynamic cell killing in vitro with 5-aminolevulinic acid.

Cell survival was investigated after exposing cells in vitro to different temperatures before or after photodynamic therapy with 5-aminolevulinic acid. The photodynamic process was found to be temperature dependent. Cells exposed for 1h to 41 degrees C before light exposure or to 7 degrees C after light exposure showed decreased survival.

Influence of human serum albumin on photodegradation of folic acid in solution.

It has been proposed that photodegradation of folates may be the reason for the pigmentation of races living under high fluence rates of ultraviolet radiation. The photodegradation of folic acid (FA) induced by ultraviolet-A (UV-A) radiation, in solution and in the presence of human serum albumin (HSA), was studied with absorption and fluorescence spectroscopy. FA photodegradation, with formation of p-aminobenzoyl-l-glutamic acid, 6-formylpterin and pterin-6-carboxylic acid, was found to follow an exponential trend.

Ultraviolet photodegradation of folic acid.

The vitamin folate is vital for all living creatures. Scientists have suggested that ultraviolet degradation of folate in vivo played a role in the evolution of mankind. In order to better understand the photodegradation of folate, we have provided a spectroscopic study of the ultraviolet photodegradation of aqueous folic acid under aerobic conditions.