The metabolism od 2:4:5-trihydroxybutyrophenone in the rat and dog.

The widespread use of phenolic antioxidants as stabilizers in foodstuffs raises the question of the manner of their disposal after intake by the animal body. It is intended to investigate the metabolism of several phenolic antioxidants, and in this paper some aspects of the metabolism in the rat and dog of 2:4:5-trihydroxybutyrophenone are discussed. This study was made during chronic-toxicity studies designed to test the suitability of 2:4:5trihydroxybutyrophenone for use as an antioxidant in foodstuffs. The metabolism of the pure compound in rats and dogs, its excretion in urine and faeces, the extent of its storage in tissues at various dose levels, and the period of retention of a single dose as 2:4:5-trihydroxybutyrophenone and any metabolic products have been examined. The metabolism of 2:4:5-trihydroxybutyrophenone presents several potentially interesting features arising from the presence of a polyhydric phenolic nucleus and a butyryl side chain. Although the metabolism of phenols has been extensively studied (Williams, 1949) and the principal routes (ethereal sulphate and glucuronide conjugation, oxidation to polyhydric phenols) are well known, much less information is available about the metabolism of polyhydric phenols. The problem of the orientation of conjugation has been discussed (Dodgson, Smith & Williams, 1950) for phenols having more than one hydroxyl available for conjugation. It seemed of particular interest to see whether 2:4:5-trihydroxybutyrophenone underwent conjugation, whether more than one conjugate was produced and whether conjugates of different orientation were formed.