This work describes for the first time the photolytic and photocatalytic degradation of 6-chloronicotinic acid (6CNA) in water. Photolytic degradation revealed no change in concentration of 6CNA within 120 min of irradiation, while the photocatalytic degradation within 120 min, obeyed first-order kinetics. In photocatalytic experiments 46 ± 7% mineralisation was achieved within 120 min of irradiation. Efficiency of degradation was investigated through toxicity assessment with Vibrio fischeri luminescent bacteria and revealed higher adverse effects of treated samples on bacteria following photocatalytic degradation. New hydroxylated product generated in photocatalytic experiments with TiO, was confirmed with LC-ESI-MS/MS, GC-MS and¹H NMR.
COBISS.SI-ID: 1964027
Model organisms are of crucial importance for studies in toxicology. Yeast Saccharomyces cerevisiae has proven to be a relevant and convenient model organism for the study of diverse biological phenomena, due to its straightforward genetics, cost-effectiveness and rapid growth, combined with the typical characteristics of a eukaryotic cell. In this review paper we described the yeast strain and plasmid collections for genome-wide experimental approaches to study complex interactions between genes, proteins and endo- or exogenous small molecules, with a focus on small pharmacologically active molecules, such as those used as UV filters.
COBISS.SI-ID: 25697319
In this study the potential estrogenicity and toxicity of BP3 and BP4 as well as chlorinated BP3 product (5-chloro BP3), which could be produced during water chlorination in swimming pools, were studied. Toxic effects of UV filters were studied on bacteria Vibrio fischeri, algae Desmodesmus subspicatus, water fleas Daphnia magna and zebrafish Danio rerio. We found that UV filter BP3 was more toxic than BP4; the highest sensitivity was observed when water fleas Daphnia magna and algae Desmodesmus subspicatus were used as test organisms. BP4 revealed adverse effects on aquatic organisms only at concentrations of some tens milligrams per liter. The acute toxicity of chlorinated product (5-chloro BP3) did not increase significantly in comparison to BP3; increased toxicity was found only in a case of algae. The results of YES assay showed no estrogenic activity of both tested UV filters and chlorinated product. This study of toxicity and estrogenicity of UV filters revealed potential adverse effects of tested UV filters on aquatic organisms. Therefore, due to existing likelihood that UV filters may pass into the aquatic environment, cognition of possible effects of new UV filters on aquatic ecosystems is required before they are commercially available on the market.
COBISS.SI-ID: 1994235
In this study, the transformation of two most widely used UV filters, benzophenone-3 (BP3) and benzophenone-4 (BP4), in chlorinated water with disinfection reagents sodium hypochlorite (NaClO) and trichloroisocyanuric acid (TCCA) was studied. Based on the HPLC/MS and UV-VIS analysis the formation of two different chlorinated products (5-chloro-2-hydroxy-4- methoxybenzophenone and 3,5-dichloro-2-hydroxy-4-methoxybenzophenone) was confirmed. Identity of chlorinated products was confirmed with independently synthesized standards. Photostability study proved dichloro-benzophenone in water to be less stable then parent compounds, which was not the case for monochloro-derivatives. Toxicity of chlorinated compounds tested by Vibrio fischeri was found to be in the same range as that of the starting compounds. Preliminary results of real water samples from swimming pools and sea swimming areas confirmed the presence of BP3 and its 3,5-dichloro derivative.