R,S-1-(2-甲氧基苯基)-4-［3-(萘-1-氧基)-2-羟基丙基］哌嗪在大鼠血浆中代谢产物的研究

目的研究R,S-1-(2-甲氧基苯基)-4-［3-(萘-1-氧基)-2-羟基丙基］哌嗪(naftopidil，NAF)在大鼠血浆中的代谢产物。方法用LC/MS法对大鼠口服NAF后的血浆样品进行分析，根据检测到的代谢产物与原形药的质谱行为及类似结构化合物的代谢规律，推测可能的代谢产物。合成对照品，通过比较代谢产物和合成对照品的色谱和质谱行为，对I相代谢物予以确认。通过质谱信息及酶水解的方法间接鉴定II相代谢物。结果大鼠血浆中发现I相代谢物：R,S-1-(2-羟基苯基)-4-［3-(萘-1-氧基)-2-羟基丙基］哌嗪(DMN)、R,S-1-(2-甲氧基-4-羟基苯基)-4-［3-(萘-1-氧基)-2-羟基丙基］哌嗪(PHN)，R,S-1-(2-甲氧基苯基)-4-［3-(4-羟基萘-1-氧基)-2-羟基丙基］哌嗪(NHN)及II相代谢物：NAF和NHN与<>-D-葡糖醛酸形成的结合物。结论NAF在大鼠血浆中的主要代谢途径是苯环、萘环羟基化和苯环邻位甲氧基的脱甲基化。此外，萘羟化代谢物和原形药与内源性分子<>-D-葡糖醛酸形成结合物也是原形药的代谢方式之一。

Metabolites of R, S-1 - ( 2-methoxyphenyl ) -4- [ 3- ( naphtha-1-yl-oxy ) -2-hydroxypropyl ]-piperazin in rat plasma

AIM: To study the metabolites of R, S-1-(2-methoxypheyl)-4-3-(naphthal-yl-oxy)-2-hydroxypropyl] -piperazine, (naftopidil, NAF), a novel antihypertensive drug in rat plasma. METHODS: The rat plasma samples were analyzed by LC/MS after oral administration of NAF. According to MS relativity of metabolites and parent compound (NAF) and metabolic rule of compound with similar structure, the structure of potential metabolites were postulated. Phase I metabolites were identified by HPLC/MS and by comparison with authentic standards, phase II conjugates were indirectly identified with beta-D-glucuronidase in presence or absence of glucuronidase selective inhibitor D-saccharric acid beta-1,4-Lactone. RESULTS: Phase I metabolites desmethyl-naftopidil (DMN), (phenyl) hydroxynaftopidil (PHN), (naphthyl) -hydroxy-naftopidil (NHN) were separated and identified in rat plasma by comparison with reference substances, phase II conjugates, NAF and NHN glucuronide conjugates were separated and tentatively identified by hydrolysis with glucuronidase, the aglycones, NAF and NHN, were identified in rat plasma. CONCLUSION: The major metabolic pathway of NAF in rat plasma should be the hydroxylation of the phenyl or nephthyl moiety of NAF and demethylation of NAF. Therefore, (naphthyl) hydroxyl-metabolite and NAF followed by conjugation with beta-glueuronic acid.