title: Physico-chemical properties and spectrophotometric determination of biologically active 1-alkyl-2-(2-pyridyl)pyridinium bromides.
abstract: Physico-chemical properties of compounds prepared from 2,2'-bipyridine, 1-alkyl-2-(2-pyridyl)pyridinium bromides, were investigated by DC polarography and by GC-MS. Their ionization potentials were calculated. Additionally, the formation of associates with bromothymol blue and methyl orange during the spectrophotometric determination was measured. It was determined that 1-alkyl-2-(2-pyridyl)pyridinium ions are reduced by 2 one-electron steps in a DC polarography system. The reduction potentials are not related to the ionization potential values calculated for the substances investigated. The carcinogenic potential (tg alpha) of the parent compound 2,2'-bipyridine and of a series of 1-alkyl derivatives was very low indicating that the compounds are not carcinogenic. The MS fragmentation patterns indicate the low stability of the 1-alkyl substituents. It was shown that 2,2'-bipyridine is either fragmented to two pyridine ions or the--N=CH--fragments are removed. Additionally, spectrophotometric determinations of colored associates of 1-alkyl-2-(2-pyridyl)pyridinium bromides with bromothymol blue and methyl orange were investigated and the optimal condiditions for these determinations are reported.
authors.affiliation: Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Health Science Center, Kuwait University, Safat, Kuwait. novotny@hsc.kuniv.edu.kw
authors.forename: L
authors.initials: L
authors.lastname: Novotny
authors.forename: A
authors.initials: A
authors.lastname: Vachalkova
authors.forename: M
authors.initials: M
authors.lastname: Blesova
authors.forename: B J
authors.initials: BJ
authors.lastname: Denny
authors.forename: D
authors.initials: D
authors.lastname: Sharma
authors.forename: Z
authors.initials: Z
authors.lastname: Ovesna
authors.forename: J
authors.initials: J
authors.lastname: Zamocka
mesh_terms: D015082:2,2'-Dipyridyl / Q000737:chemistry; D000975:Antioxidants / Q000737:chemistry; D002273:Carcinogens / Q000737:chemistry / Q000633:toxicity; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D008401:Gas Chromatography-Mass Spectrometry; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry; D010084:Oxidation-Reduction; D011048:Polarography; D011726:Pyridinium Compounds / Q000138:chemical synthesis* / Q000494:pharmacology*; D008063:Thioctic Acid / Q000737:chemistry
chemical_list: D000975:Antioxidants; D002273:Carcinogens; D011726:Pyridinium Compounds; D015082:2,2'-Dipyridyl; D008063:Thioctic Acid