Abstract

As a result of the human activity, a large number of pollutants have been generated. They are discharged into the environment, affecting the natural resources (air, soil and water). Industrial sewage has a negative impact on aquatic ecosystems. Textile wastewaters are one of the most aggressive for the environment. The wastewater from this sector contain heavy metals (chrome and cadmium) which can be found in hair dyes, as well as, nitrates and surfactants, which are being used to set dyes. In addition to heavy metals and surfactants, several authors have detected mutagenic organic compounds in water polluted from the textile industry. One of the best examples are the 2-phenylbenzotriazoles (PBTA), which were isolated and identified in the waters of the Yodo river, in Japan, which proved to be powerful pro-mutagens in the essay of Salmonella typhimurium (Ames test). The concept of pro-mutagen indicates that these molecules need a metabolic activation to exert their mutagenic activity. The metabolic activation mechanism of xenobiotic compounds has been proposed by several authors and it shows the action of the cytochrome P450 in its first step, when an OH group is put into the xenobiotic ones in order to rise their polarity and a second step where a process of enzymatic esterification is involved. The principal aims of this work is the use of global and local reactivity descriptors to try an approach to the mechanism of metabolic activation of these molecules, as well as, the molecular docking to determinate of the interaction of these compounds in the active center of the cytochrome P450. The results showed that the global reactivity descriptors remained low, what indicates a low reactivity of the PBTA against the attack of the OH - group. The results of the docking showed a right orientation in the active center of the cytochrome P450, what reproduces significantly the crystal structure of the complex CytP450-1A1-inhibitor, with π-π stacking interactions between the triazole group and the Phe224, as well as the hydrogen bond between the terminal NH 2 with the amino acids Asn255 and Ser116.