Orotic acid in milk.

Other studies in this laboratory (1) drew our attention to the possibility that erotic acid might be concerned with the maintenance of adequate lactation in the rat and with the survival of the young. Since no data were available on the erotic acid content of milk, this study was undertaken. The occurrence of erotic acid as a component of milk has been indicated since 1904, when Biscaro and Belloni (2) isolated a previously unknown compound from liquors obtained in the manufacture of lactose. Because of its occurrence in whey (opoa) they named this compound erotic acid. Its correct structure as 1,2,3,6-tetrahydro-2,6-dioxo-4-pyrimidinecarboxylic acid was not determined until 1930 (3). More recently erotic acid has been isolated from a milk liquor concentrate (4) and from “delactosed whey” (5). In view of the history of the products from which erotic acid has been isolated in the past, it was possible that it might have been a product of microbiological fermentation in the milk. The isolation of erotic acid from fresh cow’s milk was therefore considered a necessary prerequisite to studies on its concentration in the milk of cows and other species.