Miller R R, Langvardt P W, Calhoun L L, Yahrmarkt M A
Toxicol Appl Pharmacol. 1986 Mar 30;83(1):170-7. doi: 10.1016/0041-008x(86)90334-0.
Male Fischer 344 rats were given a single po dose of approximately 1 or 8.7 mmol/kg of radiolabelled propylene glycol monomethyl ether (PGME) beta isomer (2-methoxy-1-propanol). After dosing, expired air, excreta, and tissues were analyzed for 14C activity and metabolites in urine were isolated and identified. Approximately 70 to 80% of the 14C was excreted in urine while about 10 to 20% was eliminated as 14CO2 within 48 hr after dosing. The major urinary metabolite was 2-methoxypropionic acid, which accounted for approximately 93 and 79% of the radioactivity in urine from high- and low-dose animals, respectively. A glucuronide conjugate of the PGME beta isomer was also identified in urine; this metabolite accounted for approximately 3 to 4% of the radioactivity in the urine at both dosages. These results indicate that the PGME beta isomer is metabolized via different routes to different types of metabolites in comparison to the PGME alpha isomer. While the two isomers are biotransformed differently, there is a substantial toxicological data base which clearly shows that the commercial grade PGME mixture (2 to 5% beta isomer) has a low degree of biological activity.
给雄性Fischer 344大鼠经口单次给予约1或8.7 mmol/kg放射性标记的丙二醇单甲醚（PGME）β异构体（2-甲氧基-1-丙醇）。给药后，分析呼出气体、排泄物以及组织中的14C活性，并分离和鉴定尿液中的代谢产物。给药后48小时内，约70%至80%的14C经尿液排出，约10%至20%以14CO2形式排出。主要的尿液代谢产物是2-甲氧基丙酸，分别占高剂量和低剂量动物尿液中放射性的约93%和79%。尿液中还鉴定出PGMEβ异构体的葡糖醛酸缀合物；该代谢产物在两种剂量下均占尿液中放射性的约3%至4%。这些结果表明，与PGMEα异构体相比，PGMEβ异构体通过不同途径代谢为不同类型的代谢产物。虽然这两种异构体的生物转化方式不同，但大量毒理学数据库清楚地表明，商业级PGME混合物（2%至5%β异构体）的生物活性程度较低。
