Pyrrolidone carboxylate metabolism

In this chapter the enzymic reactions mentioned above will be reviewed. In addition, consideration will be given to the detection, determination, and natural occurrence of pyrrolidone carboxylic acid, the nonenzymic formation of pyrrolidone carboxylic acid, and to other information now available about the metabolism of this compound. 

There is relatively little definitive information in the literature about the metabolism of pyrrolidone carboxylic acid although several reports indicate that pyrrolidone carboxylic acid can be utilized by mammals (104, 142-146), and certain microorganism (45, 134, 147-152), information relating to the enzyme-catalyzed utilization of pyrrolidone carboxylic... 

Moisturizers often contain humectants of low molecular weight and lipids. Humectants, such as urea, glycerin, lactic acid, pyrrolidone carboxylic acid (PCA), and salts, are absorbed into the stratum corneum and there, by attracting water, increase hydration [54]. Lipids, for instance petrolatum, beeswax, lanolin, and various oils in moisturizers, have traditionally been considered to exert their effects on the skin solely by forming an inert, epicutaneous, occlusive membrane. They are incorporated into formulations on the basis of their technical and sensory properties rather than on their possible epidermal impact [52, 54]. However, topically applied lipids may also penetrate to the living cells of normal epidermis, be metabolized and significantly modify endogenous epidermal lipids [92]. In normal skin, a... 

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