Electrochemical C-H/C-C Bond Oxygenation: A Potential Technology for Plastic Depolymerization.

Herein, we provide eco-friendly and safely operated electrocatalytic methods for the selective oxidation directly or with water, air, light, metal catalyst or other mediators serving as the only oxygen supply. Heavy metals, stoichiometric chemical oxidants, or harsh conditions were drawbacks of earlier oxidative cleavage techniques. It has recently come to light that a crucial stage in the deconstruction of plastic waste and the utilization of biomass is the selective activation of inert C(sp3 )-C/H(sp3 ) bonds, which continues to be a significant obstacle in the chemical upcycling of resistant polyolefin waste. An appealing alternative to chemical oxidations using oxygen and catalysts is direct or indirect electrochemical conversion. An essential transition in the chemical and pharmaceutical industries is the electrochemical oxidation of C-H/C-C bonds. In this review, we discuss cutting-edge approaches to chemically recycle commercial plastics and feasible C-C/C-H bonds oxygenation routes for industrial scale-up.

Exploring the Synthetic Chemistry of Phenyl-3-(5-aryl-2-furyl)- 2-propen-1-ones as Urease Inhibitors: Mechanistic Approach through Urease Inhibition, Molecular Docking and Structure-Activity Relationship.

Furan chalcone scaffolds belong to the most privileged and promising oxygen-containing heterocyclic class of compounds, which have a wide spectrum of therapeutic applications in the field of pharmaceutics, pharmacology, and medicinal chemistry. This research described the synthesis of a series of twelve novel and seven reported furan chalcone (conventional synthetic approach) analogues 4a-s through the application of microwave-assisted synthetic methodology and evaluated for therapeutic inhibition potential against bacterial urease enzyme. In the first step, a series of nineteen substituted 5-aryl-2-furan-2-carbaldehyde derivatives 3a-s were achieved in moderate to good yields (40-70%). These substituted 5-aryl-2-furan-2-carbaldehyde derivatives 3a-s were condensed with acetophenone via Claisen-Schmidt condensation to furnish 19 substituted furan chalcone scaffolds 4a-s in excellent yields (85-92%) in microwave-assisted synthetic approach, while in conventional methodology, these furan chalcone 4a-s were furnished in good yield (65-90%). Furan chalcone structural motifs 4a-s were characterized through elemental analysis and spectroscopic techniques. These nineteen (19)-afforded furan chalcones 4a-s were screened for urease inhibitory chemotherapeutic efficacy and most of the furan chalcones displayed promising urease inhibition activity. The most active urease inhibitors were 1-phenyl-3-[5-(2',5'-dichlorophenyl)-2-furyl]-2-propen-1-one 4h with an IC50 value of 16.13 ± 2.45 µM, and 1-phenyl- 3-[5-(2'-chlorophenyl)-2-furyl] -2-propen-1-one 4s with an IC50 value of 18.75 ± 0.85 µM in comparison with reference drug thiourea (IC50 = 21.25 ± 0.15 µM). These furan chalcone derivatives 4h and 4s are more efficient urease inhibitors than reference drug thiourea. Structure-activity relationship (SAR) revealed that the 2,5-dichloro 4h and 2-chloro 4s moiety containing furan chalcone derivatives may be considered as potential lead reagents for urease inhibition. The in silico molecular docking study results are in agreement with the experimental biological findings. The results of this study may be helpful in the future drug discovery and designing of novel efficient urease inhibitory agents from this biologically active class of furan chalcones.

Maximizing the extraction yield of plant gum exudate using response surface methodology and artificial neural networking and pharmacological characterization.

Prunus armeniaca gum is used as food additive and ethno medicinal purpose. Two empirical models response surface methodology and artificial neural network were used to search for optimized extraction parameters for gum extraction. A four-factor design was implemented for optimization of extraction process for maximum yield which was obtained under the optimized extraction parameter (temperature, pH, extraction time, and gum/water ratio). Micro and macro-elemental composition of gum was determined by using laser induced breakdown spectroscopy. Gum was evaluated for toxicological effect and pharmacological properties. The maximum predicted yield obtained by response surface methodology and artificial neural network was 30.44 and 30.70% which was very close to maximum experimental yield 30.23%. Laser induced breakdown spectroscopic spectra confirmed the presence Calcium, Potassium, Magnesium, Sodium, Lithium, Carbon, Hydrogen, Nitrogen and Oxygen. Acute oral toxicity study showed that gum is non-toxic up to 2000 mg/Kg body weight in rabbits, accompanied by high cytotoxic effects of gum against HepG2 and MCF-7cells by MTT assay. Overall, Aqueous solution of gum showed various pharmacological activities with significant value of antioxidant, antibacterial, anti-nociceptive, anti-cancer, anti-inflammatory and thrombolytic activities. Thus, optimization of parameters using mathematical models cans offer better prediction and estimations with enhanced pharmacological properties of extracted components.

Arenes and Heteroarenes C-H Functionalization Under Enabling Conditions: Electrochemistry, Photoelectrochemistry & Flow Technology.

C-H bond functionalization generates molecular complexity in single-step transformation. However, the activation of C-H bonds requires expensive metals or stoichiometric amounts of oxidizing/reducing species. In many cases, they often require pre-functionalization of starting molecules. Such pre-activating measures cause waste generation and their separation from the final product is also troublesome. In such a scenario, reactions activating elements generating from renewable energy resources such as electricity and light would be more efficient, green, and cost-effective. Further, incorporation of growing flow technology in chemical transformation processes will accelerate the safer accesses of valuable products. Arenes & heteroarenes are ubiquitous in pharmaceuticals, natural products, medicinal compounds, and other biologically important molecules. Herein, we discussed enabling tools and technologies used for the recent C-H bonds functionalization of arenes and heteroarenes.

Heterocyclic Electrochemistry: Renewable Electricity in the Construction of Heterocycles.

Numerous applications in the realm of biological exploration and drug synthesis can be found in heterocyclic chemistry, which is a vast subject. Many efforts have been developed to further improve the reaction conditions to access this interesting family to prevent employing hazardous ingredients. In this instance, it has been stated that green and environmentally friendly manufacturing methodologies have been introduced to create N-, S-, and O-heterocycles. It appears to be one of the most promising methods to access these types of compounds avoiding use of stoichiometric amounts of oxidizing/reducing species or precious metal catalysts, in which only catalytic amounts are sufficient, and it represent an ideal way of contributing toward the resource economy. Thus, renewable electricity provides clean electrons (oxidant/reductant) that initiate a reaction cascade via producing reactive intermediates that facilitate in building new bonds for valuable chemical transformations. Moreover, electrochemical activation using metals as catalytic mediators has been identified as a more efficient strategy toward selective functionalization. Thus, indirect electrolysis makes the potential range more practical, and less side reactions can occur. The latest developments in using an electrolytic strategy to create N-, S-, and O-heterocycles are the main topic of this mini review, which was documented over the last five years.

Morphological and optical investigation of 2D material-based ternary nanocomposite: Bi2O3/MgO/GO synthesized by a co-precipitation technique.

A ternary oxide nanocomposite based on Bi2O3/MgO/GO was prepared using a co-precipitation method for photoconductive device applications. The structure and morphology of the as-prepared nanocomposite were characterized analytically using X-ray diffraction (XRD), scanning electron microscopy (SEM), electron dispersive spectroscopy (EDS) techniques, and optical characterization was made using Fourier-transform infrared (FTIR) spectroscopy, photoluminescence (PL), and UV-vis spectroscopy techniques. The heterostructure of the crystal with a crystallite size of 28.064 nm and the purity of the phase are depicted by XRD patterns. Scanning electron microscopy revealed its morphology showing an average grain size of 0.27 µm, and the purity of the nanocomposite was confirmed by EDS, which showed the presence of Mg, Bi, C, and O. The band gap of the Bi2O3/MgO/GO nanocomposite was 4.02 eV by PL comparable with 5.718 eV by UV-vis spectroscopy, which evidenced that the material may have potential applications in far UVC emissive devices. The zeta potential observed was 48.0 mV, indicating the stability of the ternary nanocomposite.

Phytochemical Constituents and In vitro Pharmacological Response of Cnidium monnieri; A Natural Ancient Medicinal Herb.

Background: Natural medicines are being used for the treatment of various disorders due to pharmacological, therapeutical, and nutraceuticals characteristics. Objectives: Current research was planned to explore In vitro pharmacological response of phytochemical constituents extracted from C. monnieri' seeds using aqueous ethanol (70%). Methods: Qualitative and quantitative measurements for phytochemical constituents were performed following reference protocols. Then In vitro antioxidant potential, cytotoxic studies, antimicrobial, and spermicidal pharmacological response of C. monnieri extract were investigated. Results: The results of High Performance Liquid Chromatography (HPLC), Fourier Transform Infra-Red (FTIR) spectroscopy, and Atomic Absorption Spectrophotometer (AAS) explored the presence of wide range of bioactive compounds with significant (p<.05) antioxidant activities. Cytotoxic studies revealed significant (p<.05) protective behavior of C. monnieri evaluated using CtDNA damage protection, against Salmonella typhi TA98 and TA100, RBCs membrane stabilizing and clot lysis assay. It was also found that selected herb has antibacterial and antifungal activities. The results of spermicidal study on human (n = 30) spermatozoa revealed significant (p<.05) contraceptive per vaginal behavior of this natural medicinal plant. Conclusion: It could be concluded that C. monnieri showed significant pharmacological activities with non-toxic behavior, however In vivo study in animals and clinical trials are required to declare this natural herb as therapeutic agent.

Thiazolidines: Potential anti-viral agents against avian influenza and infectious bronchitis viruses.

Viral outbreaks are a common cause of morbidity and mortality in livestock and human populations. Lack of good vaccines and poor control measures along with natural viral genetic drifting and shifting are the common causes of new viral strains and outbreaks. The current study reports the synthesis of some 2-aryl substituted thiazolidine-4-carboxylic acids 1a-h and their 3-acetyl 2a and 3-benzoyl derivatives 3a. Two important poultry viruses: Avian influenza virus (AIV; A/Chicken/Italy/1994/H9N2) and infectious bronchitis virus (IBV) were selected, grown in 9-11 days old chicken embryonated eggs , and subjected to in ovo anti-viral assays. Most of the synthesized compounds were found active against AIV subtype H9N2 and IBV. In the case of AIV, the best results were attained for compound 1d which showed an IC50 value of 3.47 µM, while IBV 1c showed IC50 value of 4.10 µM. The lower IC50 values of these compounds correlate with the high potency of these compounds, especially in comparison with control groups. The standard drugs amantadine and ribavarin were used as positive controls in the case of AIV and IBV, respectively. Better results were obtained with 2-aryl substituted thiazolidine-4-carboxylic acids 1a-h compared to their N-acylated derivatives 2a and 3a against both viruses. In conclusion, this preliminary data support the idea that thiazolidine carboxylic acids could be used as anti-viral drugs against AIV and IBV infections.

Synthesis and in vitro cholinesterase inhibitory potential of dihydropyridine derivatives.

Twelve derivatives of dihydropyridine derivatives (6-17) were synthesized and evaluated for in-vitro cholinesterases (AChE, BChE) inhibitory activity. All compounds showed potent activity with IC50 values between 0.21±0.003 to 147.14±0.12µM for AChE and among them five compounds showed potent activity with IC50 values 17.16±0.02 to 231.6±0.12µM for BChE when compared with standard Eserine (IC50 = 0.85±0.0001 µM (AChE) & 0.04±0.0001µM (BChE). The most potent compound 11 can be considered as potential lead compound showed an inhibition of 95.35±0.11 and IC50= 0.21±0.003 while compound 7 showed an inhibition of 83.45±0.13 and IC50= 17.16±0.02. It is concluded from structural activity relationship that the presence of nitro group at C-2 and C-4 position of dihydropyridine ring increase the acetyl cholinesterase and butyrylcholinesterase activities of these compounds while presence of -Br and -Cl also enhances the activities.

Microwave and conventional synthesis of Co (II), Cu (II) and Ni (II) metal complexes of some acid hydrazones with their spectral characterization and biological evaluation.

The transition metal complexes of Co(II), Ni(II), and Cu(II) derived from N'-((5-(2,5-dichlorophenyl)furan-2-yl)methylene)-2-hydroxybenzohydrazide (L24) and N'-((5-(2, 5-dichlorophenyl)furan-2-yl)methylene)benzohydrazide (L21) have been synthesized by conventional as well as microwave method being shorter time consuming, solvent less and gives improved yields as compared to the traditional conventional technique. These compounds were characterized by melting point, TLC, FTIR, 1H-NMR, elemental analysis, potentiometric titration, ICP-OES and EIMS. From this analytical data it is confirmed that complexes are in octahedral structure with coordination number 6 which revealed 1:2 (metal:ligand). FTIR data shows that these synthesized hydrazone ligands have ONO donor sites and coordinate with transition metal ions in a tridentate monobasic manner. All these synthesized compounds were tested for evaluation of antibacterial activity by agar disc diffusion assay and total antioxidant activity by Phosphomolybdenum method.