人尿中苯丙哌林羟基化代谢产物的研究

目的　研究苯丙哌林在人体内的羟基化代谢过程。方法　选择10名健康男性受试者单剂量口服60 mg苯丙哌林,收集0～24 h尿样,经固相萃取后用LC/MSⁿ法检测羟基化代谢产物。利用微生物转化法和半制备HPLC获得其中两种代谢产物的对照品,并经NMR鉴定结构。根据质谱断裂规律进一步推测结合型代谢物的结构。结果 在人尿中发现苯丙哌林的5种羟基化代谢产物和它们与内源性葡糖醛酸和硫酸的结合物,与代谢物对照品的液相色谱和质谱信息比较,确证了其中两种代谢产物的结构分别为4″-羟基苯丙哌林和4″-羟基苯丙哌林。结论　苯丙哌林的羟基化代谢优先发生在芳环烷氧基对位,5种羟基化代谢产物在尿中主要以葡糖苷酸或硫酸酯结合物形式存在。

STUDY ON HYDROXYLATED METABOLITES OF BENPROPERINE IN HUMAN URINE

AIM: To investigate the hydroxylation process of benproperine in humans. METHODS: After an oral administration of 60 mg benproperine to ten healthy male volunteers, urine samples collected within 0-24 h were extracted by solid phase extraction and analyzed by liquid chromatography-ion trap mass spectrometry. A microbial transformation of benproperine combined with semi-preparative HPLC was used to get two reference substances of the hydroxylated metabolites, and their structures were then elucidated by NMR. Furthermore, the structures of conjugated metabolites were speculated based on their characteristics in MS fragmentation. RESULTS: Five hydroxylated metabolites of benproperine and some of their conjugates with endogenous glucuronic acid or sulfuric acid were found in urine of volunteers after the dose. The structures of two metabolites were identified as 4"-hydroxybenproperine and 4"'-hydroxybenproperine by comparison of HPLC retention times and mass spectra with those of authentics obtained from the microbial transformation. CONCLUSION: Hydroxylation of benproperine occurs preferentially at para-position of the alkoxyl group in the aromatic ring. The hydroxylated metabolites of benproperine in human urine mainly exist as their glucuronic acid or sulfuric acid conjugates.