Radiolytic reactions of nitro blue tetrazolium under oxidative and reductive conditions: a pulse radiolysis study

The response characteristics of tetrazolium violet solutions to gamma irradiation

“…for dosimetry. The most widely studied systems are the 2,3,5-triphenyl-tetrazolium chloride (TTC), blue and nitroblue tetrazolium salts (BT, NBT), investigated both in solutions and in solid matrices (Gierlach and Krebs, 1949;Kovacs et al, 1999). In the case of all tetrazolium salts studied it was shown, that the radiolytic reduction of the salts resulted in the final formazan product via the formation of the tetrazolium radical.…”

Pulse radiolysis of tetrazolium violet in aqueous and aqueous-alcoholic solutions under oxidative and reductive conditions

“…2) in self-termination reaction, resulting in the formation of monoformazan. Self-termination of the tetrazolinyl radicals was also suggested in the case of other tetrazolium compounds (Kriminskaya et al, 1988a;Ková cs et al, 1999a):…”

“…In a few cases mechanistic studies were also performed using ESR spectroscopy at low temperatures (Kriminskaya et al, 1987a(Kriminskaya et al, , 1991. Pulse radiolysis studies have been conducted in aqueous and aqueous-alcoholic (ethanol, isopropanol) solutions of tetrazolium molecules containing three phenyl substituents (2,3,5-triphenyl-tetrazolium chloride, TTC) (Kriminskaya et al, 1984(Kriminskaya et al, , 1988aKová cs et al, 1996), two phenyl and one pnitrophenyl substituent (2-p-nitrophenyl-3.5-diphenyltetrazolium chloride (p-NTC) (Kriminskaya et al, 1988a) and with a ditetrazolium compound having phenyl, p-nitrophenyl and mmethoxyphenyl substituents (nitro blue tetrazolium chloride, NBTC) (Bielski et al, 1980;Ková cs et al, 1999a). It was shown that under reducing conditions in aqueous solutions the solvated electron, while in aqueous-alcoholic solutions both the solvated electron and the a-hydroxyalkyl radicals reduce the tetrazolium ring into the electron adduct tetrazolinyl radical.…”

Practical use of chemical probes for reactive oxygen species produced in biological systems by γ-irradiation

“…When the pale yellow NBT reacts with O 2 dÀ , a dark blue insoluble diformazan compound is produced (Beyer and Fridovich, 1987). Otherwise, the reduction of NBT can be mediated by e À aq produced by water radiolysis, resulting in the formation of monoformazan and diformazan (Ková cs et al, 1999b). The formation of diformazan, however, was induced by g-irradiation at least beyond 5 kGy (Ková cs et al, 1999a).…”