摘要：On the way of the study on the metabolism of α-bromoisovalerylurea (BV), a series of new mass fragment ions (m/e 103, 115, 130, 144, 175, and 190) was observed in the mass spectrum of crude extracts from BV-administered rabbit urine. After purification of the extracts by silica gel column chromatography and subsequent thin-layer chromatography (TLC), small pieces of crystals were obtained and characterized to be 2-(methylthio)-3-methylbutyrylurea (BM) by comparison of melting point, Rf value in TLC, mass spectrum, and infrared spectrum with those of the standard BM, synthesized from BV and methylmercaptan. In order to know the amount of BM excreted by the isotope dilution method using a mass spectrometer, 2-(methylthio-d3)-3-methylbutyrylurea (BMd3) was synthesized from BV, thiourea, and methyld3 iodide. After the administration of 1 g of BV to a male rabbit (ca. 3.5kg), approximately 4 mg of BM was found to be excreted in the urine within 30 hr.
