The In Vitro Metabolic Study Of Five Benzodiaze-Pines Drugs

The benzodiazepines drugs (BZDs), belonging to the central nervous system drugs, have broad pharmacological effects such as calming the anxiety, resistance to epilepsy and convulsions, helping hypnosis, and using for preoperative anesthesia, etc. With the ability in interfering the human brain and central nervous system, BDZs are used to commit anesthesia robbery, rapes, fraud and other criminal activities by the criminals, which do serious harm to the social and public safety.The biotransformation is the metabolism of drug. As BZDs are metabolized easily and the elimination half-life period is short, there is very little probability of detecting the parent drugs in the biological samples. So the study of the in-vitro metabolism, identification of the metabolites, and the metabolic pathways of BDZs was important to the clinical medicine and forensic science.In this thesis, based on the in-vitro metabolism model of human and rat liver microsomes, and advanced analytic techniques (SPE, GC-MS, LC-LIT-MS), the metabolism of BZDs such as diazepam, chlordiazepoxide, nitrazepam, clonazepam and triazolam was studied. By comparison with previous in vivo metabolic study and the partial standards, the metabolites and main metabolic pathways in human and rat liver microsomes of BZDs were deduced. Ten metabolites:7-chloro-2-methoxy-5-phenyl-3H-1,4-benzodiazepine,5-(4-hydroxyphenyl)-clonazepam, desmethyltriazolam, desmethyl-5-N-oxide-clonazepam, desmethyl-6-(4-hydroxyphenyl)-5-N-oxideclonazepam,6-(4-hydr-oxyphenyl)-clonazepam,(2-N-oxidetriazolo)-5-N-oxideclonazepam,6-(4-hydr-oxyphenyl)-5-N-oxideclonazepam, a-hydroxy-5-N-oxideclonazepam, and a-hydroxy-6-(4-hydroxyphenyl)-clonazepam were reported for the first time. At the same time, the metabolic studies of diazepam, chlordiazepoxide, nitrazepam, clonazepam and triazolam were improved. A rapid method for the determination of19BZDs and their metabolites in blood and urine was developed via online-SPE high pressure liquid chromatography-linear ion trap mass spectrometry with electron spray ionization method. A mass spectrum library was developed by using LC-MS, including product ions and grandchild ions of50common poisons and their metabolites. The in-vitro metabolic study provides a strong reference for the fighting against illegal and criminal activities, and will be of great significance in the clinical medicine and forensic science.