Electrochemical reduction potentials of 1-nitropyrene, 9-nitroanthracene, 6-nitrochrysene and 3-nitrofluoranthene and their correlation with direct-acting mutagenicities

Abstract

Neste trabalho, são apresentados os potenciais de meia-onda de redução, determinados para 3-nitrofluoranteno (3-NF) = -0,51V, 1-nitropireno (1-NP) = -0,61V, 6-nitrocriseno (6-NC) = -0,64V, e 9-nitroantraceno (9-NA) = -0,84V. Os experimentos de voltametria cíclica com os nitro-PAH foram conduzidos em N,N-dimetilformamida anidra (DMF) contendo perclorato de tetraetilamônio 0,1 mol L -1 (TEAP), usando-se uma célula de três compartimentos, equipada com eletrodos de trabalho e auxiliar de platina e eletrodo de referência de Ag/AgI (fio de prata imerso em DMF / TEAP 0,1 mol L -1 , contendo iodeto de tetrabutilamônio 0,05 mol L -1 ). Esses potenciais podem ser ordenados do menos negativo para o mais negativo, o que corresponde à mesma ordem com que decresce a ação mutagênica direta (3-NF >> 1-NP > 6-NC >> 9-NA). Assim, o 3-NF, que apresentou o potencial de meia-onda menos negativo é, entre os nitro-PAH estudados, o de maior atividade mutagênica. Deste modo, estas propriedades podem ser utilizadas como indicativas do risco à saúde humana da exposição a nitro-PAH, sendo, portanto, de grande importância em estudos toxicológicos.In this work, we report measured electrochemical half-wave reduction potentials of 3-nitrofluoranthene (3-NF), 1-nitropyrene (1-NP), 6-nitrochrysene (6-NC) and 9-nitroanthracene (9-NA): = -0.51V; -0.61V; -0.64V; and -0.84V respectively. The cyclic voltammetry experiments with the nitro-PAH were carried out in anhydrous N,N-dimethylformamide (DMF), containing 0.1 mol L -1 tetraethylammonium perchlorate (TEAP) using a three-compartment cell fitted with Pt working and auxiliary electrodes, and a Ag/AgI reference electrode (a silver wire in 0.1 mol L -1 DMF/TEAP containing 0.05 mol L -1 tetrabutylammonium iodide). These potentials can be ordered from the less to the more negative value, which corresponds to the same order by which the direct-acting mutagenicity decreases (3-NF >> 1-NP > 6-NC >> 9-NA). Thus, 3-NF, which shows the less negative first halfwave potential value is the more active mutagenic amongst the nitro-PAH studied. In this way, these properties may be used as an indicative of the health risks, asociated to nitro-PAH exposure, and thus being of great importance in toxicological studies.

Density Functional Theoretical Study of Mono-Nitrated Fluoranthenes

“…On the basis of Koopman's theorem (45) (47) show that the first half-wave potential (-E pc ) follows the trend: 3-NF > 1-NP > 6-NC > 9-NA, which is in agreement with their known direct-acting mutagenicity, and correlates with their nitro group orientation. In previous studies (48) it was demonstrated that the half-wave potentials may be correlated to direct mutagenicity.…”

Electroanalysis of Nitro and Amino Derivatives of Polycyclic Aromatic Hydrocarbons

“…From the electrochemical point of view, the studies showing positive correlation between reduction potential and direct mutagenicity of structurally similar NPAHs [86,96] are interesting. The relationship between polarographic and/or voltammetric behavior and genotoxic properties of NPAHs and the knowledge of the mechanism of their electrode reactions can thus give us a useful clue in the elucidation of the mechanism of their interaction with living cells and their fate in the environment.…”

“…Moreover, the study of polarographic and voltammetric behavior of biologically active organic compounds can provide a great amount of information about their electron-transfer reactions [86]. This can be useful in elucidation of the mechanism of their interaction with living cells [87], because both electrochemical and biological reactions are essentially heterogenous processes occurring at the electrode-solution or enzyme-solution interface [88].…”

Influence of structural and functional modifications of selected genotoxic carcinogens on metabolism and mutagenicity – a review

“…Less negative values signify ease of reduction whereas more negative values indicate otherwise. A recent study demonstrated that the decrease in electrochemical half-wave reduction potentials of 3-nitrofluoranthene (3-NF), 1-nitropyrene (1-NP), 6-nitrochrysene (6-NC) and 9-nitroanthracene (9-NA) (3-NF (À0.51V)4 41-NP (À0.61V)46-NC (À0.64V)4 49-NA (À0.84V)) corresponded to the decrease of their direct-acting mutagenicity [132]. The 9-NA which has the nitro group nearly perpendicular to the aromatic ring displayed the most negative peak potential and exerted a very low direct-acting mutagenicity.…”