Further observations on changes in β-glucuronidase activity in the mouse

removed. The filtrate was treated with charcoal and evaporated to dryness in vacuo. The residue was dis- solved in the minimum necessary amount of boiling water and the solution made just alkaline with ammonia. The precipitate formed by addition of excess of saturated basic lead acetate was collected, suspended in water (100 ml.)and treated with hydrogen sulphide to remove lead. After addition of excess Na2S2O4, the lead-free ifitrate was con- tinuously extracted with ether. The ethereal extract was concentrated in vacuo to give a syrup which, on treatment with small volumes of water and chilling, gave a crude product, m.p. 1050, consisting mainly of 2:5-dihydroxytoluene. Recrystallization from water gave colourless needles, m.p. 1240, mixed m.p. with authentic 2:5-dihydroxytoluene (m.p. 1250), 1250. Yield 50 mg. (1 % of dose). ( Found: C, 67-5; H, 6-6. Calc. for C7H802: C, 67-7; H, 6-5 %.) The identity of the isolated metabolite with 2:5-dihydroxytoluene was further confirmed by paper chromatography and by the preparation of the dibenzoyl derivative, m.p. 118-119, alone or mixed with an authentic specimen. 2:5-Dihydroxytoluene was similarly isolated from o-cresol urine. Yield 10 mg. from a total dose of 5 g.