This research focuses on the synthesis and
in vitro
anticancer evaluation of functionalized 2-aryl-5-(4-piperazin-1-yl)oxazoles and 5-(4-arylsulfonyl) piperazin-1-yl-2-phenyloxazoles. Oxazoles are a ...versatile class of compounds with diverse biological activities, making them attractive targets in medicinal chemistry. We incorporated amino and sulfonamide functionalities into the oxazole scaffold, as they have shown potential for interacting with biological targets. The synthesis of target oxazole derivatives was accomplished using 2-aroylamino-3,3-dichloroacrylonitriles as starting materials and employing efficient reaction conditions. The resulting compounds exhibited structural features that make them promising candidates for further chemical modifications and biological evaluations. Additionally, a series of sulfonamides were synthesized from 5-(piperazin-1-yl)oxazole-4-carbonitrile hydrochloride, offering diverse bioactivity and versatile structural characteristics. However, no potent inhibitors of malignant cell growth were identified among the tested compounds. Nevertheless, we categorized the investigated substances into two distinct groups based on their activity profile. Group A, comprising sulfonamides, displayed pronounced anticancer activity against breast cancer and melanoma cell lines. On the other hand, group B, the 2-aryl-5-(4-R-piperazin-1-yl)oxazole-4-carbonitriles, exhibited a moderate effect primarily on renal cancer cell lines. These findings provide valuable insights for further structural modifications in the quest for more potent anticancer agents.
We report Peacock-Weakley complexes, Na 9 Ln(W 5 O 18) 2 ·35H 2 O, formed with Tm(III), 1, and Yb(III), 2. Their syntheses, physico-chemical characterizations, crystal structures, and magnetic ...properties are described. Ab initio calculations are also reported. These polyoxometalate (POM) complexes were obtained using original synthetic conditions where acidification was performed with a stoichiometric amount of nitric acid to an acidity of Z = ν(H +)/ν(WO 4 2-) = 8/10 = 0.80. Both the Tm(III) and Yb(III) derivatives were found to exhibit field-induced slow relaxation of their magnetization likely controlled by Raman and Orbach relaxation processes. 1 is a rare example of a Tm(III)-based single-molecule magnet (SMM) and is a consequence of the oblate tetragonal anti-prismatic symmetry of the coordination sphere.
We report Peacock–Weakley complexes, Na9Ln(W5O18)2∙35H2O, formed with Tm(III), 1, and Yb(III), 2. Their syntheses, physico-chemical characterizations, crystal structures, and magnetic properties are ...described. Ab initio calculations are also reported. These polyoxometalate (POM) complexes were obtained using original synthetic conditions where acidification was performed with a stoichiometric amount of nitric acid to an acidity of Z = ν(H+)/ν(WO42–) = 8/10 = 0.80. Both the Tm(III) and Yb(III) derivatives were found to exhibit field-induced slow relaxation of their magnetization likely controlled by Raman and Orbach relaxation processes. 1 is a rare example of a Tm(III)-based single-molecule magnet (SMM) and is a consequence of the oblate tetragonal anti-prismatic symmetry of the coordination sphere.
This paper shows that 25‐propyloxy‐26,27‐dibenzoyloxy‐calix4arene can be a convenient precursor for the formation of inherently chiral configuration on the calixarene platform. The methods for ...sequential regioselective debenzoylation and electrophilic substitution on the upper rim were developed. The inherently chiral calix4renes with two and three different functional groups on the upper rim were synthesized.
This paper shows that 25‐propyloxy‐26,27‐dibenzoyloxy‐calix4arene can be a convenient precursor for the formation of inherently chiral configuration on the calixarene platform. The methods for ...sequential regioselective debenzoylation and electrophilic substitution on the upper rim were developed. The inherently chiral calix4renes with two and three different functional groups on the upper rim were synthesized.
25‐Propyloxy‐26,27‐dibenzoyloxy‐calix4 is a convenient precursor for the formation of inherently chiral configuration on the calixarene platform. The synthesis of inherently chiral calixarenes with one, two and three different functional groups on the upper rim was described.
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•Advancements in Ionic Liquid usage for biomass pretreatment as a green alternative.•Comparative analysis of Ionic Liquid pretreatment with other common methodologies.•Critical ...analysis of pretreatment modeling and Ionic Liquid solvation parameters.•Techno-economic viability of Ionic liquid based commercial scale pretreatment plant.•SWOT analysis with identification of knowledge gaps and future research directions.
Lignocellulosic biomass is the most plentiful renewable biomolecule and an alternative bioresource for the production of biofuels and biochemicals in biorefineries. But biomass recalcitrance is a bottleneck in their usage, thus necessitating their pretreatment for hydrolysis. Most pretreatment technologies, result in toxic by-products or have lower yield. Ionic liquids (ILs) have successfully advanced as ‘greener and recyclable’ alternatives to volatile organic solvents for lignocellulosic biomass dissolution. This review covers recent developments made in usage of IL-based techniques with focus on biomass breakdown mechanism, process parameter design, impact of cation and anion groups, and the advantageous impact of ILs on the subsequent processing of the fractionated biomass. Progress and barriers for large-scale commercial usage of ILs in emerging biorefineries were critically evaluated using the principles of economies of scale and green chemistry in an environmentally sustainable way.
Bacterial infections are one of the leading causes of death worldwide. In the case of topical bacterial infections such as wound infections, silver (Ag) has historically been one of the most widely ...used antibacterials. However, scientific publications have demonstrated the adverse effects of silver on human cells, ecotoxicity and insufficient antibacterial effect for the complete elimination of bacterial infections. The use of Ag in the form of nanoparticles (NPs, 1-100 nm) allows to control the release of antibacterial Ag ions but is still not sufficient to eliminate infection and avoid cytotoxicity. In this study, we tested the potency of differently functionalized copper oxide (CuO) NPs to enhance the antibacterial properties of Ag NPs. The antibacterial effect of the mixture of CuO NPs (CuO, CuO-NH
and CuO-COOH NPs) with Ag NPs (uncoated and coated) was studied. CuO and Ag NP combinations were more efficient than Cu or Ag (NPs) alone against a wide range of bacteria, including antibiotic-resistant strains such as gram-negative Escherichia coli and Pseudomonas aeruginosa as well as gram-positive Staphylococcus aureus, Enterococcus faecalis and Streptococcus dysgalactiae. We showed that positively charged CuO NPs enhanced the antibacterial effect of Ag NPs up to 6 times. Notably, compared to the synergy of CuO and Ag NPs, the synergy of respective metal ions was low, suggesting that NP surface is required for the enhanced antibacterial effect. We also studied the mechanisms of synergy and showed that the production of Cu
ions, faster dissolution of Ag
from Ag NPs and lower binding of Ag
by proteins of the incubation media in the presence of Cu
were the main mechanisms of the synergy. In summary, CuO and Ag NP combinations allowed increasing the antibacterial effect up to 6 times. Thus, using CuO and Ag NP combinations enables to retain excellent antibacterial effects due to Ag and synergy and enhances beneficial effects, since Cu is a vital microelement for human cells. Thus, we suggest using combinations of Ag and CuO NPs in antibacterial materials, such as wound care products, to increase the antibacterial effect of Ag, improve safety and prevent and cure topical bacterial infections.
The effect of counterions was investigated to probe the principal ionic effects on the solubility in water and melting behavior of cationic gemini surfactants. We focused on two types of counterions: ...(1) small inorganic counterions that are typically taken from the Hofmeister series were studied to focus on the effect of ion type and (2) n-alkylcarboxylate counterions were studied to focus on the effect of the hydrophobicity of counterions. The Krafft temperature (T k) and melting temperature (T m) were obtained by conductivity measurements, calorimetric measurements, and optical microscopy observation. The results clearly indicate that T k, which represents the solubility of surfactants, is not determined by a single parameter of ions such as the hydration free energy, as is too often assumed, but rather by the combined effects between the hydrophobicity of anions associated with other effects such as the polarizability, dehydrated ion size, and ionic morphology. In parallel, our observation demonstrated that all of the surfactants showed a transition from a crystalline phase to a thermotropic liquid-crystalline phase at around ca. 70 °C, which transformed to an isotropic liquid phase at around ca. 150 °C, and that the transition temperatures depended strongly on the counterion type. The counterion effects on the solubilization and melting behaviors were then compared with micellization properties that have been reported previously. These results provide new insight into understanding the effect of ions on the delicate balance of forces controlling the solution properties and aggregate morphology of charged amphiphilic molecules. Specifically, the solubilization properties of these cationic surfactants with various counterions were determined mainly by the subtle interplay between the hydration of counterions and the dissociation energies (stability of crystallinity) of the ion pair.
The world today is not only facing the problem of depleting energy sources but also generation of waste from anthropogenic activities. While waste is a risk, it is also an opportunity to solve this ...dual problem through utilization of waste as a potential source of energy and products. In order to reconcile the management of waste to the scale of its production, several researches are being pursued. Establishment of bioeconomy is a great way to achieve this goal. But inherent challenges associated with biowaste include manageability of by-products and sludge, wide variety in waste composition, efficiency of the process and economic viability of treatment technologies to scale-up and industrialize beyond laboratory setup. Recent advancements have been made in this regard with the use of new techniques, synergistic catalysts, combination of technologies and novel treatment materials to remediate the challenges and maximize the value of waste by utilizing it as a feedstock to produce industrial chemicals, fuels and materials. This review provides an insight into these developments, along with the critical discussion, limitations and economic feasibility of waste valorization technologies to provide new understanding for the advancement of bioeconomy.
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•Waste valorization advancements will drive sustainable utilization of resources.•Treatment technology choice depends on waste feedstock and desired product output.•Tuning operational parameters can yield outputs with desired characteristics.•Combining multiple valorization technologies can yield better product.
The effect of counterions was investigated and analyzed to probe the principal ionic effects influencing the micellization behavior of dimeric cationic surfactant ...ethanediylbis(dimethyltetradecylammonium), referred to as gemini 14-2-14. The 30 counterions were classified to four different families depending on their nature: (1) small and inorganic counterions which are typically taken from the Hofmeister series were studied to focus on the effect of ion type; (2) n-alkyl carboxylate counterions were studied to focus on the effect of the hydrophobicity of counterions; (3) aromatic carboxylate counterions were included to focus on the effect of the position of substitutions; and (4) other counterions were included in order to shed light on other parameters. By investigating the critical micelle concentration (CMC), ionization degree of micelle (α), free energy of micellization (Δ G M), and aggregation numbers N of the gemini surfactant with these different types of anions, we demonstrated the effect of different ion properties independently. This approach allowed us to describe the effect of counterions on the micellization behavior of the gemini surfactant in terms of complex interplay between hydrophobicity of anions and other ion properties such as counterion hydration, interfacial packing of ions, and ionic morphology. Indeed, our results clearly demonstrate that a counterion effect on micellization properties cannot be described as a result of one single parameter of ions, as is too often assumed, but rather the balancing effects cooperatively affect the propensity of counterions to form ion pairs with surfactant headgroups and the entropy gain upon micellization. These results provide new insight in understanding the effect of ions on the delicate balance of forces controlling aggregate morphology and solution properties of charged amphiphilic molecules.
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