-
Scientific Reports May 2020Sulfadiazine (SD), sulfamerazine (SM1), and sulfamethazine (SM2) are widely used and disorderly discharged into surface water, causing contamination of lakes and rivers....
Sulfadiazine (SD), sulfamerazine (SM1), and sulfamethazine (SM2) are widely used and disorderly discharged into surface water, causing contamination of lakes and rivers. However, microalgae are regard as a potential resource to alleviate and degrade antibiotic pollution. The physiological changes of Chlorella vulgaris in the presence of three sulfonamides (SAs) with varying numbers of -CH groups and its SA-removal efficiency were investigated following a 7-day exposure experiment. Our results showed that the growth inhibitory effect of SD (7.9-22.6%), SM1 (7.2-45.9%), and SM2 (10.3-44%) resulted in increased proteins and decreased soluble sugars. Oxidative stress caused an increase in superoxide dismutase and glutathione reductase levels but decreased catalase level. The antioxidant responses were insufficient to cope-up with reactive oxygen species (hydrogen peroxide and superoxide anion) levels and prevent oxidative damage (malondialdehyde level). The ultrastructure and DNA of SA-treated algal cells were affected, as evident from the considerable changes in the cell wall, chloroplast, and mitochondrion, and DNA migration. C. vulgaris-mediated was able to remove up to 29% of SD, 16% of SM1, and 15% of SM2. Our results suggest that certain concentrations of specific antibiotics may induce algal growth, and algal-mediated biodegradation process can accelerate the removal of antibiotic contamination.
Topics: Anti-Bacterial Agents; Catalase; Chlorella vulgaris; Chlorophyll; Fresh Water; Glutathione Reductase; Malondialdehyde; Microalgae; Oxidative Stress; Photosynthesis; Reactive Oxygen Species; Sulfonamides; Superoxide Dismutase; Water Pollutants
PubMed: 32427937
DOI: 10.1038/s41598-020-65219-2 -
BMC Chemistry Dec 2020A novel polystyrene sulfonate sodium (PSS) magnetic material was prepared by surface-initiated atom transfer radical polymerization (SI-ATRP). The starting materials...
A novel polystyrene sulfonate sodium (PSS) magnetic material was prepared by surface-initiated atom transfer radical polymerization (SI-ATRP). The starting materials were brominated magnetic material as the carrier and macroinitiator, sodium styrene sulfonate (NaSS) as the monomer, and cuprous bromide/2,2'-dipyridyl as the catalyst system. The PSS material was characterized by Fourier transform infrared spectroscopy (FT-IR), elemental analysis, transmission electron microscope (TEM), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and a vibrating sample magnetometer (VSM). The adsorption properties of the material were then investigated on sulfa antibiotics. The kinetic and thermodynamic parameters were determined in adsorption of sulfamethazine (the smallest molecular-weight sulfonamide). The adsorption amount of sulfamerazine free acid (SMR) was found to increase with the initial concentration and temperature of SMR in solution. The adsorption effect was maximized at an initial concentration of 0.6 mmol/L. The static saturation adsorption capacity of the material was 33.53 mg/g, Langmuir and Freundlich equations exhibited good fit. The thermodynamic equilibrium equation is calculated as ΔG < 0, ΔH = 38.29 kJ/mol, ΔS > 0, which proves that the adsorption process is a process of spontaneous, endothermic and entropy increase. Kinetic studies show that the quasi-second-order kinetic equation can better fit the kinetic experimental results, which is consistent with the quasi-second-order kinetic model. The experimental results of kinetic studies were well fitted to a quasi-second-order kinetic equation. High performance liquid chromatography (HPLC) of an actual milk sample treated by the PSS magnetic material confirmed the strong adsorption of SMR from milk.
PubMed: 31956861
DOI: 10.1186/s13065-019-0658-8 -
BMC Bioinformatics Nov 2019S-sulphenylation is a ubiquitous protein post-translational modification (PTM) where an S-hydroxyl (-SOH) bond is formed via the reversible oxidation on the Sulfhydryl...
BACKGROUND
S-sulphenylation is a ubiquitous protein post-translational modification (PTM) where an S-hydroxyl (-SOH) bond is formed via the reversible oxidation on the Sulfhydryl group of cysteine (C). Recent experimental studies have revealed that S-sulphenylation plays critical roles in many biological functions, such as protein regulation and cell signaling. State-of-the-art bioinformatic advances have facilitated high-throughput in silico screening of protein S-sulphenylation sites, thereby significantly reducing the time and labour costs traditionally required for the experimental investigation of S-sulphenylation.
RESULTS
In this study, we have proposed a novel hybrid computational framework, termed SIMLIN, for accurate prediction of protein S-sulphenylation sites using a multi-stage neural-network based ensemble-learning model integrating both protein sequence derived and protein structural features. Benchmarking experiments against the current state-of-the-art predictors for S-sulphenylation demonstrated that SIMLIN delivered competitive prediction performance. The empirical studies on the independent testing dataset demonstrated that SIMLIN achieved 88.0% prediction accuracy and an AUC score of 0.82, which outperforms currently existing methods.
CONCLUSIONS
In summary, SIMLIN predicts human S-sulphenylation sites with high accuracy thereby facilitating biological hypothesis generation and experimental validation. The web server, datasets, and online instructions are freely available at http://simlin.erc.monash.edu/ for academic purposes.
Topics: Algorithms; Amino Acid Motifs; Amino Acid Sequence; Area Under Curve; Computational Biology; Conserved Sequence; Databases, Protein; Gene Ontology; Humans; Neural Networks, Computer; Proteome; ROC Curve; Software; Sulfamerazine
PubMed: 31752668
DOI: 10.1186/s12859-019-3178-6 -
Angewandte Chemie (International Ed. in... Oct 2019Sulfonimidamides are intriguing new motifs for medicinal and agrochemistry, and provide attractive bioisosteres for sulfonamides. However, there remain few operationally... (Review)
Review
Sulfonimidamides are intriguing new motifs for medicinal and agrochemistry, and provide attractive bioisosteres for sulfonamides. However, there remain few operationally simple methods for their preparation. Here, the synthesis of NH-sulfonimidamides is achieved directly from sulfenamides, themselves readily formed in one step from amines and disulfides. A highly chemoselective and one-pot NH and O transfer is developed, mediated by PhIO in iPrOH, using ammonium carbamate as the NH source, and in the presence of 1 equivalent of acetic acid. A wide range of functional groups are tolerated under the developed reaction conditions, which also enables the functionalization of the antidepressants desipramine and fluoxetine and the preparation of an aza analogue of the drug probenecid. The reaction is shown to proceed via different and concurrent mechanistic pathways, including the formation of novel S≡N sulfanenitrile species as intermediates. Several alkoxy-amino-λ -sulfanenitriles are prepared with different alcohols, and shown to be alkylating agents to a range of nucleophiles.
Topics: Alcohols; Amines; Molecular Structure; Nitriles; Sulfamerazine; Sulfonamides
PubMed: 31390133
DOI: 10.1002/anie.201906001