title: Identification, separation and characterization of process-related impurities of bifendate derivative (DB-6), an investigational agent combating acute liver failure.
abstract: DB-6, with an IUPAC name of (Z)-5-(2,4-di-tert-butyl-6-((2,4-dioxothiazolidin-5-ylidene)methyl)phenyl)-5'-methyl-7,7'-dimethoxy-[4,4'-bibenzo[d][1,3]dioxole]-5,5'-dicarboxylate, is an investigational agent for acute liver failure. The focus of this study is the identification and characterization of major unknown impurities in DB-6 bulk drug samples. Four major impurities of DB-6 were detected by a high-performance liquid chromatography (HPLC) method and designated as IMP-I, IMP-II, IMP-III and IMP-IV. Accurate masses of these impurities were determined by using a Q-TOF mass spectrometer. Based on chromatographic, spectrometric data and plausible chemical transformation mechanism, the structures of IMP-I, IMP-II, IMP-III and IMP-IV were identified, respectively, as bifendate, (E)-5-(2,4-di-tert-butyl-6-((2,4-dioxothiazolidin-5-ylidene)methyl)phenyl)-5'-methyl-7,7'-dimethoxy-[4,4'-bibenzo[d][1,3]dioxole]-5,5'-dicarboxylate, (Z)-5-(3,5-di-tert-butyl-2-hydroxybenzylidene) thiazolidine-2,4-dione and bis(2,4-di-tert-butyl-6-((Z)-(2,4-dioxothiazolidin-5-ylidene)methyl)phenyl)-7,7'-dimethoxy-[4,4'-bibenzo[d][1,3]dioxole]-5,5'-icarboxylate. The impurities were isolated by preparative-HPLC or preparative high-speed counter-current chromatography and their structures were confirmed by NMR spectroscopy.
authors.affiliation: State Key Laboratory of Biotherapy/Collaborative Innovation Center for Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan 610065, PR China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Ye
authors.affiliation: Pharmaceutical and Biological Engineering Department, Institute for Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, PR China.
authors.forename: Yinghong
authors.initials: Y
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Biotherapy/Collaborative Innovation Center for Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan 610065, PR China.
authors.forename: Guangcheng
authors.initials: G
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Biotherapy/Collaborative Innovation Center for Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan 610065, PR China luo_youfu@scu.edu.cn.
authors.forename: Youfu
authors.initials: Y
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Biotherapy/Collaborative Innovation Center for Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan 610065, PR China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Chen
mesh_terms: D001713:Biphenyl Compounds / Q000737:chemistry* / Q000302:isolation & purification* / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D004340:Drug Contamination; D015507:Drugs, Investigational / Q000737:chemistry* / Q000302:isolation & purification* / Q000494:pharmacology; D006801:Humans; D017114:Liver Failure, Acute / Q000188:drug therapy; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure
chemical_list: D001713:Biphenyl Compounds; D015507:Drugs, Investigational; C465548:bifendate