Abstract
A new metabolite of caffeine in the urine of the horse, rabbit, rat, and mouse was isolated and identified as α-[7-(1, 3-dimethylxanthinyl)] methyl methyl sulfoxide (II). Other two new metabolites were isolated from the urine of the mouse administered caffeine andidentified as α-[7-(1, 3-dimethylxanthinyl)] methyl methyl sulfide (I) and α-[7-(1, 3-dimethylxanthinyl)] methyl methyl sulfone (III), respectively. The structural elucidation of these metabolites is described.