11/02/2024


Some metals in oil sands process water (OSPW) are potential threats to human health and the environment. Hence, the removal of excess metals from OSPW is of great significance. In this study, anaerobic sludge waste from a wastewater treatment plant, was reused to prepare sludge-based biochar. A Biochar/Chitosan (Biochar/CS) adsorbent with excellent removal efficiency for metals (Cr, Cu, Se and Pb) in real OSPW was prepared through a facile hydrothermal method. The structural properties of the synthesized Biochar/CS composite were characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) method. This study reports for the first time the removal of metals from OSPW under natural pH using Biochar/CS adsorbent. The composite exhibited a higher removal efficiency towards Cr (83.9%), Cu (97.5%), Se (87.9%) and Pb (94.3%) when the initial concentrations of Cr, Cu, Se and Pb were 0.02914, 0.06185, 0.00800 and 0.00516 mg/L, respectively, at a dosage of 0.5 g/L, compared with biochar or chitosan alone. The possible adsorption mechanism was proposed, and the enhanced removal ability was due to the improved specific surface area and pore volume, which increased by about 20 and 14 times as compared with chitosan. Functional groups in the composite, such as -NH2, -OH and some oxygen containing groups, were also responsible for the enhanced removal ability, which also might be the reason for the better performance of the composite than biochar alone due to the lack of functional groups on the biochar. Moreover, the adsorption process was best modelled by the Freundlich model, pseudo second order and intraparticle diffusion kinetic models. The results indicated that chemical adsorption might play the dominant role in the removal process. Overall, the Biochar/CS composite would be a promising and effective adsorbent for metals removal, owing to its advantages of being cost-effective and environmentally friendly.The global increase in cyanobacterial blooms poses environmental and health threats. Selected cyanobacterial strains reveal toxicities despite a lack of synthesis of known toxic metabolites, and the mechanisms of these toxicities are not well understood. Here we investigated the toxicity of non-cylindrospermopsin and non-microcystin producing Aphanizomenon gracile and Raphidiopsis raciborskii of Central European origin to zebrafish exposed for 14 days to their extracts. Toxicological screening revealed the presence of anabaenopeptins and a lack of anatoxin-a, ß-methylamino-L-alanine or saxitoxins in examined extracts. The responses were compared to 20 μg L-1 of common cyanobacterial toxins cylindrospermopsin (CYN) and microcystin-LR (MC-LR). The expression of the marker genes involved in apoptosis (caspase 3a and 3b, Bcl-2, BAX, p53, MAPK, Nrf2), DNA damage detection and repair (GADD45, RAD51, JUN, XPC), detoxification (CYP1A, CYP26, EPHX1), lipid metabolism (PPARa, FABP1, PLA2), phosphorylation/dephosphorylantral European strain of A. gracile and R. raciborskii did not reveal a genotoxic potential. These findings help to further understand the ecotoxicological consequences of toxic cyanobacterial blooms in freshwater ecosystems.In our attempt to develop potential anticancer agents targeting Topoisomerase I (TOP1), two novel series of 4-alkoxy-2-arylquinolines 14a-p and 19a-c were designed and synthesized based on structure activity relationships of the reported TOP1 inhibitors and structural features required for stabilization of TOP1-DNA cleavage complexes (TOP1ccs). https://www.selleckchem.com/products/ps-1145.html The in vitro anticancer activity of these two series of compounds was evaluated at one dose level using NCI-60 cancer cell lines panel. Compounds 14e-h and 14m-p, with p-substituted phenyl at C2 and propyl linker at C4, were the most potent and were selected for assay at five doses level in which they exhibited potent anticancer activity at sub-micromolar level against diverse cancer cell lines. Compound 14m was the most potent with full panel GI50 MG-MID 1.26 μM and the most sensitive cancers were colon cancer, leukemia and melanoma with GI50 MG-MID 0.875, 0.904 and 0.926 μM, respectively. Melanoma (LOX IMVI) was the most sensitive cell line to all tested compounds displaying GI50 from 0.116 to 0.227 μM, TGI from 0.275 to 0.592 μM and LC50 at sub-micromolar concentration against almost of the tested compounds. Compounds 14e-h and 14m-p were assayed using TOP1-mediated DNA cleavage assay to evaluate their ability to stabilize TOP1ccs resulting in cancer cell death. The morpholino analogs 14h and 14p exhibited moderate TOP1 inhibitory activity compared to 1 μM camptothecin suggesting their use as lead compounds that can be optimized for the development of more potent anticancer agents with potential TOP1 inhibitory activity. Finally, Swiss ADME online web tool predicted that compounds 14h and 14p possessed good oral bioavailability and druglikeness characteristics.Iminopyridine-decorated carbosilane metallodendrimers have recently emerged as a promising strategy in the treatment of cancer diseases. Their unique features such as the nanometric size, the multivalent nature and the structural perfection offer an extraordinary platform to explore structure-to-property relationships. Herein, we showcase the outstanding impact on the antitumor activity of a parameter not explored before the iminopyridine substituents in meta position. New Cu(II) carbosilane metallodendrimers, bearing methyl or methoxy substituents in the pyridine ring, were synthesized and thoroughly characterized. Electron Paramagnetic Resonance (EPR) was exploited to unveil the properties of the metallodendrimers. This study confirmed the presence of different coordination modes of the Cu(II) ion (Cu-N2O2, Cu-N4 and Cu-O4), whose ratios were determined by the structural features of the dendritic molecules. These metallodendrimers exhibited IC50 values in the low micromolar range ( less then 6 μM) in tumor cell lines such as HeLa and MCF-7. The subsequent in vitro assays on both healthy (PBMC) and tumor (U937) myeloid cells revealed two key facts which improved the cytotoxicity and selectivity of the metallodrug First, maximizing the Cu-N2O2 coordination mode; second, adequately selecting the pair ring-substituent/metal-counterion. The most promising candidates, G1(-CH3)Cl (8) and G1(-OCH3)NO3(17), exhibited a substantial increase in the antitumor activity in U937 tumor cells, compared to the non-substituted counterparts, probably through two different ROS-production pathways.