title: Kinetic and analytic investigations on the formation of N-nitroso-N-methyl-N-cyclohexylamine from bromhexine and nitrite.
abstract: Bromhexine (N-methyl-N-cyclohexyl-(2-amino-3,5-dibromobenzyl)-ammoniumhydr ochloride) forms N-nitroso-N-methyl-N-cyclohexylamine (NMCA) under the conditions of the WHO Nitrosation Assay Procedure (NAP-test). The formation kinetics of this compound was investigated. The formation of NMCA depends on the square of the nitrite concentration. The reaction has a narrow pH-optimum at pH 3. The reaction is quick: After 1 h about 70% of the maximum amount of NMCA is formed. To study this reaction kinetics sensitive assays with a detection limit up to 0.5 ng/ml NMCA were developed. The stability of the components of the system, especially that of NMCA and nitrite, were further studied. The latter is rather instable under conditions found in an acidic stomach.
authors.affiliation: Research Laboratories, Dr. Karl Thomae GmbH, Biberach an der Riss, Fed. Rep. of Germany.
authors.forename: J
authors.initials: J
authors.lastname: Schmid
authors.forename: K
authors.initials: K
authors.lastname: Daneck
authors.forename: F W
authors.initials: FW
authors.lastname: Koss
authors.forename: G
authors.initials: G
authors.lastname: Eisenbrand
authors.forename: K H
authors.initials: KH
authors.lastname: Schlemmer
mesh_terms: D001964:Bromhexine / Q000032:analysis*; D015197:Carcinogenicity Tests; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D005750:Gastric Juice / Q000032:analysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007700:Kinetics; D009573:Nitrites / Q000032:analysis*; D009602:Nitrosamines / Q000032:analysis / Q000096:biosynthesis / Q000138:chemical synthesis*; D012463:Saliva / Q000032:analysis; D014556:Urine / Q000032:analysis
chemical_list: D009573:Nitrites; D009602:Nitrosamines; C058573:4-hydroxy-N-nitroso-N-methyl-N-cyclohexylamine; D001964:Bromhexine; C025137:N-nitroso-N-methylcyclohexylamine