Search Results (9)

The degradation of bisphenol A (BPA), the main monomer of polycarbonate, was investigated under subcritical water conditions to better understand its decomposition as a function of process conditions and to provide useful data for designing a recycling process to convert polycarbonate into valuable products. Hydrothermal experiments were conducted in a batch reactor at temperatures ranging from 250 to 350 °C, with reaction times from 5 to 30 min and water-to-material ratios of 5, 10, and 15 (mL/g), following a Box–Behnken design with response surface methodology (RSM). The influence of process parameters on phase distribution, total carbon content, and product composition was evaluated. The results showed that temperature and reaction time were the most significant factors affecting BPA decomposition, while the water-to-material ratio had a minor effect. The recovery of the DEE (diethyl ether)-soluble phase decreased with increasing temperature and time, accompanied by a corresponding increase in the water-soluble phase yield and total carbon content. Analysis of the DEE-soluble fraction revealed the sequential transformation of BPA into 4-isopropenylphenol, 4-isopropylphenol, and phenol, with phenol becoming the dominant degradation product at higher temperatures. These findings provide new insights into the hydrothermal decomposition mechanism of BPA and form a basis for understanding polycarbonate degradation and developing sustainable subcritical water recycling processes for polymeric materials. Full article

Endocrine-disrupting chemicals (EDCs) are exogenous substances discharged into the environment through human activities. 3-Isopropylphenol, a typical alkylphenol-based EDC, has been extensively studied due to its broad application and potential ecological impacts. However, the mechanism of its neurotoxicity remains unclear. In this study, the neurotoxic effects of 3-isopropylphenol were examined using the zebrafish model. We predicted its potential toxic mechanisms and action targets using network toxicology and molecular docking and verified them via RT-qPCR. Results showed that 3-isopropylphenol exposure inhibits the cAMP/PKA signaling pathway in zebrafish larvae, promoting apoptosis, impairing neural development, and suppressing locomotor behavior. These findings enhance our understanding of the toxic effects and mechanisms of 3-isopropylphenol on zebrafish larval neural development and aid in evaluating its potential ecological hazards. Full article

Candida auris, an emerging non-albicans multidrug-resistant yeast, has become a significant cause of invasive candidiasis in healthcare settings. So far, data on the metabolites of C. auris in different clades are minimal, and no studies have focused on clade V metabolites. Therefore, Gas chromatography–mass spectrometry (GC-MS) was used for the metabolomic profiling of clade I C. auris compared with fluconazole-resistant and susceptible C. auris in clade V strains. GC-MS chromatography revealed 28, 22, and 30 compounds in methanolic extracts of the fluconazole-susceptible and fluconazole-resistant C. auris clade V and C. auris clade I strain, respectively. Some compounds, such as acetamide and metaraminol, were found in fluconazole-susceptible and resistant C. auris clade V and clade I. N-methyl-ethanamine and bis(2-ethylhexyl) phthalate metabolites were found in both fluconazole -susceptible and resistant C. auris clade V, as well as 3-methyl-4-isopropylphenol, 3,5-bis(1,1-dimethyl)-1,2-benzenediol, and diisostyl phthalate metabolites in both fluconazole resistant C. auris clade V and I. Identifying these metabolites contributes to understanding the morphogenesis and pathogenesis of C. auris, highlighting their potential role in antifungal drug resistance and the control of fungal growth. However, further experiments are warranted to fully comprehend the identified metabolites’ regulatory responses, and there may be potential challenges in translating these findings into clinical applications. Full article

The aim of this work has been to study the possible degradation path of BPA under the Fenton reaction, namely to determine the energetically favorable intermediate products and to compare the cytotoxicity of BPA and its intermediate products of degradation. The DFT calculations of the Gibbs free energy at M06-2X/6-311G(d,p) level of theory showed that the formation of hydroquinone was the most energetically favorable path in a water environment. To explore the cytotoxicity the erythrocytes were incubated with BPA and three intermediate products of its degradation, i.e., phenol, hydroquinone and 4-isopropylphenol, in the concentrations 5–200 μg/mL, for 1, 4 and 24 h. BPA induced the strongest hemolytic changes in erythrocytes, followed by hydroquinone, phenol and 4-isopropylphenol. In the presence of hydroquinone, the highest level of RONS was observed, whereas BPA had the weakest effect on RONS generation. In addition, hydroquinone decreased the level of GSH the most. Generally, our results suggest that a preferable BPA degradation path under a Fenton reaction should be controlled in order to avoid the formation of hydroquinone. This is applicable to the degradation of BPA during waste water treatment and during chemical degradation in sea water. Full article

A large number of studies of Cistus ladanifer highlight this Mediterranean shrub as a source of the phenolic compounds responsible for the allelopathic potential of this species. There are few phenolic compounds present in C. ladanifer that have not yet been studied. The objective of this work was to evaluate the activity of estragole and 2-isopropylphenol on filter paper and soil on monocotyledons (Allium cepa) and dicotyledons (Lactuca sativa). The results showed that when the test was carried out on paper, the germination and the growth of the L. sativa was strongly inhibited by 2 isopropylphenol and estragole. 2 isopropylphenol showed an IC₅₀ on the germination of 0.7 mM and 0.1 mM on the germination rate, 0.4 mM on the size of radicle and 0.3 mM on the size of hypocotyl. Estragole showed an IC50 on the germination rate of 1.5 mM and 1.1 mM on the size of hypocotyl. The effects of these pure compounds on A. cepa were lower, and when the assays were performed on the soil, they were dissipated. The mixture of these compounds on A. cepa had 0.6 mM IC₅₀ for the length hypocotyl on paper and 1.1 mM for the length of the radicle on soil. The mixture on L. sativa also inhibited the length of the radicle with an IC₅₀ of 0.6 mM. On the other hand, it was also observed that estragole stimulated the growth of the A. cepa radicle length on soil, showing a hormetic effect with an EC₅₀ of 0.1 mM. In conclusion, it can be said that for a species to be allelopathic in nature, it is essential to verify the effect of its possible allelochemicals on the target species, on the soil in which they will exert their action and at the concentrations found in their usual environment, in addition to taking into account the interaction with other compounds present in the medium. Full article

A TiO₂ nanoparticle-loaded polymer fiber web was developed as a functional material with the ability to adsorb and photo-catalytically degrade organic pollutants in aquatic media. A linear copolymer of N-isopropylacrylamide (primary component) and N-methylol acrylamide (poly(NIPA-co-NMA)) was prepared, and composite fibers were fabricated by electrospinning a methanol suspension containing the copolymer and commercially available TiO₂ nanoparticles. The crosslinking of the polymer via the formation of methylene bridges between NMA units was accomplished by heating, and the fiber morphology was analyzed by electron microscopy. 4-Isopropylphenol generated by the degradation of bisphenol A—one of the endocrine-disrupting chemicals—was used as the model organic pollutant. As poly(NIPA) is a thermosensitive polymer that undergoes hydrophilic/hydrophobic transition in water, the temperature-dependence of the adsorption and photocatalytic degradation of 4-isopropylphenol was investigated. The degradation rate was analyzed using a pseudo-first-order kinetic model to obtain the apparent reaction rate constant, k_app. The enhancement of the photocatalytic degradation rate owing to the adsorption of 4-isopropylphenol onto thermosensitive poly(NIPA)-based fibers is discussed in terms of the ratio of the k_app of the composite fiber to that of unsupported TiO₂ nanoparticles. Based on the results, an eco-friendly wastewater treatment process involving periodically alternated adsorption and photocatalytic degradation is proposed. Full article

A PAlP pincer ligand derived from 2-diphenylphosphino-6-isopropylphenol was synthesized. The Lewis acidity of the Al center of the ligand was evaluated with coordination of (O)PEt₃. A zwitterionic rhodium-aluminum heterobimetallic complex bearing the PAlP ligand was synthesized through its complexation with [RhCl(nbd)]₂. Moreover, reduction of the zwitterionic rhodium-aluminum complex with KC₈ afforded heterobimetallic complexes bearing an X-type PAlP pincer ligand. Full article

A series of phenolic compounds containing 2-phenylphenol (PPE), bisphenol A (BPA), 4-isopropylphenol (IPE), 4-methylphenol (ME) and phenol (PE) were selected to investigate their major influence factors for their adsorption on graphene oxide (GO) and reduced graphene oxide (RGO) by studying their adsorption isotherms and kinetics. It was found that the adsorption of all tested phenols fitted well with the Freundlich model. In comparison, the adsorption ability of RGO with a stronger π-π interaction was superior to GO, which was confirmed by using naphthalene probe measurements. The thermodynamic characteristics, by studying the effect of the adsorption temperatures (298, 313 and 333 K), demonstrated that the adsorption process was spontaneous, exothermic and entropy-decreasing. The chemical structures of the phenols also affected their adsorption on GO and RGO. It was found that the adsorption capacities of phenols were, in order, PE (0.271 mmol g⁻¹ on GO and 0.483 mmol g⁻¹ on RGO) < ME (0.356 and 0.841 mmol g⁻¹) < IPE (0.454 and 1.117 mmol g⁻¹) < BPA (0.4 and 1.56 mmol g⁻¹) < PPE (0.7 and 2.054 mmol g⁻¹), which depended on the π-electron density of the benzene ring by means of a density functional theory (DFT) calculation. Undoubtedly, the reduction of GO and an increase in π-electron density on the chemical structures of phenols facilitated the adsorption. Full article