Expression of concern: Acceleration of ammonium phosphate hydrolysis using TiO2 microspheres as a catalyst for hydrogen production.

Expression of concern for 'Acceleration of ammonium phosphate hydrolysis using TiO2 microspheres as a catalyst for hydrogen production' by Ayman H. Zaki et al., Nanoscale Adv., 2020, 2, 2080-2086, https://doi.org/10.1039/D0NA00204F.

Facile one-pot synthesis and in silico study of new heterocyclic scaffolds with 4-pyridyl moiety: Mechanistic insights and X-ray crystallographic elucidation.

4-Acetylpyridine 1 and malononitrile 2 were allowed to react in a 3MCRs with dimedone 3a or cyclohexa-1,3-dione 3b under reflux to afford 4-methyl-4-(pyridin-4-yl)-5,6,7,8-tetrahydro-4H-chromene derivatives 4a,b respectively. The mechanism of the reaction has been studied and the structures elucidated by analytical, spectral as well as X-ray crystallographic data. Heterocyclic compounds find widespread application in pharmaceutical and agrochemical products. Docking analyses were performed on the synthesized compounds to assess their binding modes with various amino acids of the target protein tubulin (PDB Code - 1SA0). The results indicated promising binding scores for compounds 4a and 4b, suggesting a strong affinity for the tubulin binding site. Finally, ADMET for the synthesized compounds 4a, 4b, 5, 8a and 8b were carried out. The drug likeness and pharmacokinetic properties of the prepared compounds were also evaluated. Notably, all of the novel compounds adhered to Lipinski's rule (Ro5) without any violations.

Green Biocatalyst for Ultrasound-Assisted Thiazole Derivatives: Synthesis, Antibacterial Evaluation, and Docking Analysis.

The catalytic activity of chitosan (Cs) and grafted Cs led to the preparation of terephthalohydrazide Cs Schiff's base hydrogel (TCsSB), which was then investigated as an eco-friendly biocatalyst for synthesizing novel thiazole derivatives. TCsSB exhibited greater surface area and higher thermal stability compared to Cs, making it a promising eco-friendly biocatalyst. We synthesized two novel series of thiazoles via the reaction of 2-(2-oxo-1,2-diphenylethylidene) hydrazine-1-carbothioamide with various hydrazonoyl chlorides and 2-bromo-1-arylethan-1-ones, employing ultrasonic irradiation and using TCsSB as a catalyst. A comparative study between Cs and TCsSB revealed higher yields than TCsSB. The methodology offered advantages such as mild reaction conditions, quick reaction times, and high yields. TCsSB could be reused multiple times without a significant loss of potency. The chemical structures of the newly synthesized compounds were verified through IR, 1H NMR, 13C NMR, and MS analyses. Six synthesized compounds were assessed for their in vitro antibacterial effectiveness by establishing the minimum inhibitory concentration against four distinct bacterial strains. The docking analyses revealed favorable binding scores against several amino acids within the selected protein (PDB Code-1MBT) for these compounds, with compound 4c exhibiting particularly noteworthy binding properties. Additionally, the in silico ADME parameter estimation for all compounds indicated favorable pharmacological properties for these compounds.

Synthesis of Bis-thiazoles Tethered 1,4-Dihydropyridine and Pyridine Linkers via Simple Oxidation and their Molecular Docking as VEGFR -TK Inhibitors.

AIM: In this study, a neoteric and expedient oxidation method is applied for a variety of Hantzsch 1,4-dihydropyridine derivatives such as 1,4-dihydro- 2,6-dimethyl-3,5-diacetylpyridine, 3,5-bis-hydrazono--2,6-dimethyl-1,4-dihydropyridine, and 3,5-bis-thiazoly-2,6-dimethyl-1,4-dihydro pyridine. METHOD: This simple oxidation is based upon the in situ generation of nitrous acid from an aqueous sodium nitrite and acetic acid mixture and could be used to downgrade costs, sustain resources, and minimize chemical wastes. Also, a molecular modeling strategy was used to study the mechanism of action for various derivatives of bis-hydrazinylidene- thiazole as the protein Vascular Endothelial Growth Factor Receptor Tyrosine Kinase (VEGFR TK) inhibitor through evaluating their binding scores and modes compared with Sorafenib as a reference standard. RESULT: The results revealed that the interaction of hydrazinylidene and thiazole as an anticancer Tyrosine Kinase inhibitor has been improved. CONCLUSION: Additionally, the compounds exhibiting the highest activity were assessed for their potential anticancer effects against HepG-2, MCF-7, and WI-38 cells, and the outcomes demonstrated encouraging activity against cancer.

Chitosan-sulfonic acid-catalyzed green synthesis of naphthalene-based azines as potential anticancer agents.

Aim: This study focuses on advancing green chemistry in anticancer drug discovery, particularly through the synthesis of azine derivatives with a naphthalene core using CS-SO3H as a catalyst. Methods: Novel benzaldazine and ketazine derivatives were synthesized using (E)-(naphthalen-1-ylmethylene)hydrazine and various carbonyl compounds. The methods employed included thermal and grinding techniques, utilizing CS-SO3H as an eco-friendly and cost-effective catalyst. Results: The approach resulted in high yields, short reaction times and demonstrated catalyst reusability. Cytotoxicity tests highlighted compounds 3b, 11 and 13 as potent against the HEPG2-1. Conclusion: This study successfully aligns with the objectives of eco-conscious drug development in organic chemistry. Molecular docking and in silico studies further indicate the potential of these ligands as antitumor medicines, with favorable oral bioavailability properties.

Occurrence, distribution, and composition of black sand along the Red Sea, Egypt.

Black sand along the Red Sea is often composed of volcanic minerals and heavy minerals. The Red Sea region is known for its unique geological features, and black sand beaches can be found in various areas along its shores. The study presents a comprehensive semi-quantitative chemical analysis of black sand samples collected from various locations along the red sea, revealing significant variations in their elemental compositions. The main oxides were identified in each sample, determined through X-ray diffraction (XRD) and X-ray fluorescence (XRF) analyses, indicate diverse mineralogical compositions. The spatial distribution of minerals at each site is depicted through mapping. Additionally, Fourier-transform infrared (FTIR) spectra offer information on the functional groups present in the samples, revealing the existence of hydroxyl groups, aliphatic compounds, and adsorbed water molecules. For Qusier-Elsharm Alqbly, Safaga, Marsa Alam, Gabal Alrosass, Hurghada Titanic, Hurghada Elahiaa, Gemsa, and Ras Elbehar samples, the results highlight the presence of various minerals, such as Quartz, Calcite, Titanium Dioxide, Magnetite, Hematite, Aluminum Oxide, Zirconium Dioxide, Chromium (III) Oxide, and others, providing insights into the geological characteristics of each location. The differences in mineral content among the examined sites are linked to the geological and mineralogical makeup of the source rocks upstream and midstream in the basins that discharge into the surveyed regions. So, variations in black sand concentrations among different locations offer insights into the geological and mineralogical diversity of the studied areas along the Red Sea coast. This study addresses the existing knowledge gap by focusing on the preliminary exploration and description of the occurrence, distribution, and composition of black sand along the Red Sea in Egypt. whereas the results provide valuable insights into the geological diversity of black sand deposits in the surveyed areas, underscoring the need for additional research and interpretation of these variations. Therefore, the in-depth examination of mineralogical composition and crystal structures establishes a foundation for future investigations in the field of geology and earth sciences.

Recent Literature on the Synthesis of Thiazole Derivatives and their Biological Activities.

The thiazole ring is naturally occurring and is primarily found in marine and microbial sources. It has been identified in various compounds such as peptides, vitamins (thiamine), alkaloids, epothilone, and chlorophyll. Thiazole-containing compounds are widely recognized for their antibacterial, antifungal, anti-inflammatory, antimalarial, antitubercular, antidiabetic, antioxidant, anticonvulsant, anticancer, and cardiovascular activities. The objective of this review is to present recent advancements in the discovery of biologically active thiazole derivatives, including their synthetic methods and biological effects. This review comprehensively discusses the synthesis methods of thiazole and its corresponding biological activities within a specific timeframe, from 2017 until the conclusion of 2022.

Novel xylenyl-spaced bis-thiazoles/thiazines: synthesis, biological profile as herpes simplex virus type 1 inhibitors and in silico simulations.

Aims: Development of some potent bis-thiazole and bis-thiazine derivatives that could be used as antiviral prototypes. Materials & methods: Xylenyl-spaced bis-carbazone scaffold 3 was used as a versatile building block for bis-thiazole derivatives 6a-e and 9a-d and bis-thiazine derivatives 12a-f. These bis-heterocycles were screened as herpes simplex virus type 1 (HSV-1) inhibitors. Results: The new bis-heterocyclic compounds showed remarkable antiviral activity (e.g., compound 6d cytotoxicity concentration CC50 >500 µg/ml). The antiviral capacity of the synthesized bis-compounds was supported by a molecular docking study against the glycoprotein D receptor of HSV-1. Compounds 6b, 9b, and 12c displayed the best binding coefficients. Conclusion: A new series of xylenyl-spaced bis-carbazone scaffolds were used as a building scaffold to construct a host of bis-thiazole/thiazine derivatives that could be used as antiviral prototypes.

Three series of potent antiviral prototypes were successfully designed. The building blocks of these prototypes are readily accessible from commercially available starting materials. These prototypes were tagged with thiazole moieties due to their diverse biological activities. These analogues were screened as herpes simplex virus type 1 (HSV-1) inhibitors to examine their antiviral potential. In vitro screening revealed that several prototypes possess good antiviral activities against an HSV-1 receptor compared with acyclovir. Compound 6d showed remarkable antiviral activity with a cytotoxicity concentration CC₅₀ >500 µg/ml. The antiviral capability of the newly synthesized materials was supported by computational calculations against the surface glycoprotein D receptor of the HSV-1. Compounds 6b, 9b and 12c had the best binding affinity toward the target protein receptor, with binding energies of -9.5, -9.8 and -9.6 kcal/mol, respectively. These results were in great accord with the recorded in vitro screening data.

Novel maleic anhydride derivatives: liquid crystalline materials with enhanced mesomorphic and optical characteristics.

A new class of liquid crystalline materials, 4-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)phenyl 4-(alkoxy)benzoates (Mn), derived from maleic anhydride, was synthesized and studied for mesomorphic and optical properties. These materials consist of three derivatives with varying terminal flexible chain lengths (6-12 carbons) linked to the phenyl ring near the ester bond. The study employed differential scanning calorimetry and polarized optical microscopy (POM) to characterize the mesomorphic properties. Molecular structures were elucidated using elemental analysis, FT-IR, and NMR spectroscopy. The findings reveal that all the synthesized maleic anhydride derivatives exhibit enantiotropic nematic (N) mesophases. The insertion of the heterocyclic maleic anhydride moiety into the molecular structure influences the stability and range of the N phase. Additionally, entropy changes during N-isotropic transitions are of small magnitude and exhibit non-linear trends independent of the terminal alkoxy chain length (n). This suggests that the ester linkage group does not significantly promote molecular biaxiality, and the clearing temperature values are relatively high. By comparing the investigated materials with their furan derivatives found in existing literature, it was established that the substitution examined in this study induces the formation of nematic phases.

Synthesis, Biological Evaluation, and Molecular Docking of Novel Azolylhydrazonothiazoles as Potential Anticancer Agents.

A novel set of thiazolylhydrazonothiazoles bearing an indole moiety were synthesized by subjection reactions of carbothioamide derivative and hydrazonoyl chlorides (or α-haloketones). The cytotoxicity of the synthesized compounds was evaluated against the colon carcinoma cell line (HCT-116), liver carcinoma cell line (HepG2), and breast carcinoma cell line (MDA-MB-231), and demonstrated encouraging activity. Furthermore, when representative products were assessed for toxicity against normal cells, minimal toxic effects were observed, indicating their potential safety for use in pharmacological studies. The mechanism of action of the tested products, as inhibitors of the epidermal growth factor receptor tyrosine kinase domain (EGFR TK) protein, was suggested through docking studies that assessed their binding scores and modes, in comparison to a reference standard (W19), thus endorsing their anticancer activity.

Green Synthetic Approaches of 2-Hydrazonothiazol-4(5H)-ones Using Sustainable Barium Oxide-Chitosan Nanocomposite Catalyst.

The diverse applications of metal oxide-biopolymer matrix as a nanocomposite heterogenous catalyst have caused many researches to scrutinize the potential of this framework. In this study, a novel hybrid barium oxide-chitosan nanocomposite was synthesized through a facile and cost-effective co-precipitation method by doping barium oxide nanoparticles within the chitosan matrix at a weight percentage of 20 wt.% BaO-chitosan. A thin film of the novel hybrid material was produced by casting the nanocomposite solution in a petri dish. Several instrumental methods, including Fourier-transform infrared (FTIR), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD), were used to analyze and characterize the structure of the BaO-CS nanocomposite. The chemical interaction with barium oxide molecules resulted in a noticeable displacement of the most significant chitosan-specific peaks in the FTIR spectra. When the surface morphology of SEM graphs was analyzed, a dramatic morphological change in the chitosan surface was also discovered; this morphological change can be attributed to the surface adsorption of BaO molecules. Additionally, the patterns of the XRD demonstrated that the crystallinity of the material, chitosan, appears to be enhanced upon interaction with barium oxide molecules with the active sites, OH and NH2 groups, along the chitosan backbone. The prepared BaO-CS nanocomposite can be used successfully as an effective heterogenous recyclable catalyst for the reaction of N,N'-(alkane-diyl)bis(2-chloroacetamide) with 2-(arylidinehydrazine)-1-carbothioamide as a novel synthetic approach to prepare 2-hydrazonothiazol-4(5H)-ones. This new method provides a number of benefits, including quick and permissive reaction conditions, better reaction yields, and sustainable catalysts for multiple uses.

Synthesis and Molecular Docking Study of Some New Thiazole-coumarin Molecular Hybrids as Antibacterial Agents.

BACKGROUND: The emergence of drug-resistant bacteria and multidrug-resistant diseases, both of which are associated with high mortality, has posed a serious global health issue. Thiazoles and coumarins were reported as antimicrobial agents. OBJECTIVE: This research paper aims to describe the synthesis of some novel thiazole derivatives bear-ing a coumarin residue as antibacterial agents Methods: The thiazole - coumarin hybrids were synthesized starting from the condensation of 3-acetyl coumarin (1) hydrazine carbothioamide (2) or thisemicarbazide then reacting the resulting products with different p-substituted phenacyl bromides (4a-e), hydrazonoyl chlorides (8a-e), and (11). In vitro antibacterial activity was studied in this work. In addition, molecular docking studies for the new compounds have also been carried out to investigate the binding mode of actions against the target DNA gyrase B. RESULTS: Some of the newly synthesized compounds such as compounds 10b, 7, and 6b showed pronounced activities against Gram (+ve) and Gram (-ve) bacteria compared to a reference antibacterial agent. Compounds 10b, 7, and 6b exhibited the best binding affinity against the target. CONCLUSION: We could obtain a series of precious hitherto unknown thiazole derivatives with varied antibacterial activities from cheap laboratory-available starting material following rather simple environmentally friendly techniques avoiding the use of hazardous or heavy metal-containing catalysts.

Synthesis, In Vitro Evaluation and Molecular Docking Studies of Novel Thiophenyl Thiazolyl-Pyridine Hybrids as Potential Anticancer Agents.

Many literature reports revealed the anticancer activity of pyridine and thiazole derivatives, especially in lung cancer. Therefore, a new series of thiazolyl pyridines linked with thiophene moiety via hydrazone group was prepared by one-pot multi-component reaction of (E)-1-(4-methyl-2-(2-(1-(thiophen-2-yl)ethylidene)hydrazinyl)thiazol-5-yl)ethanone with benzaldehyde derivatives and malononitrile in a good yield. Then, compound 5 and the thiazolyl pyridines were investigated for their in vitro anticancer activity against lung cancer (A549) cell line using MTT assay compared to doxorubicin as a reference drug. The structure of all the newly synthesized compounds was established based on spectroscopic data and elemental analyses. For better insight to investigate their mechanism of action on A549 cell line, docking studies were performed, targeting epidermal growth factor receptor (EGFR) tyrosine kinase. The results obtained revealed that the tested compounds displayed excellent anticancer activities against lung cancer cell line except 8c and 8f compared to reference drug. Based on the data obtained, it can be inferred that the novel compounds, as well as their key intermediate, compound 5, demonstrated potent anticancer activity against lung carcinoma by inhibiting EGFR.

Mechanochemical Synthesis and Molecular Docking Studies of New Azines Bearing Indole as Anticancer Agents.

The development of new approaches for the synthesis of new bioactive heterocyclic derivatives is of the utmost importance for pharmaceutical industry. In this regard, the present study reports the green synthesis of new benzaldazine and ketazine derivatives via the condensation of various carbonyl compounds (aldehydes and ketones with the 3-(1-hydrazineylideneethyl)-1H-indole using the grinding method with one drop of acetic acid). Various spectroscopic techniques were used to identify the structures of the synthesized derivatives. Furthermore, the anticancer activities of the reported azine derivatives were evaluated against colon, hepatocellular, and breast carcinoma cell lines using the MTT technique with doxorubicin as a reference medication. The findings suggested that the synthesized derivatives exhibited potential anti-tumor activities toward different cell lines. For example, 3c, 3d, 3h, 9, and 13 exhibited interesting activity with an IC50 value of 4.27-8.15 µM towards the HCT-116 cell line as compared to doxorubicin (IC50 = 5.23 ± 0.29 µM). In addition, 3c, 3d, 3h, 9, 11, and 13 showed excellent cytotoxic activities (IC50 = 4.09-9.05 µM) towards the HePG-2 cell line compared to doxorubicin (IC50 = 4.50 ± 0.20 µM), and 3d, 3h, 9, and 13 demonstrated high potency (IC50 = 6.19-8.39 µM) towards the breast cell line (MCF-7) as compared to the reference drug (IC50 = 4.17 ± 0.20 µM). The molecular interactions between derivatives 3a-h, 7, 9, 11, 13, and the CDK-5 enzyme (PDB ID: 3IG7) were studied further using molecular docking indicating a high level of support for the experimental results. Furthermore, the drug-likeness analysis of the reported derivatives indicated that derivative 9 (binding affinity = -8.34 kcal/mol) would have a better pharmacokinetics, drug-likeness, and oral bioavailability as compared to doxorubicin (-7.04 kcal/mol). These results along with the structure-activity relationship (SAR) of the reported derivatives will pave the way for the design of additional azines bearing indole with potential anticancer activities.

Synthesis, Molecular Docking, and Dynamic Simulation Targeting Main Protease (Mpro) of New, Thiazole Clubbed Pyridine Scaffolds as Potential COVID-19 Inhibitors.

Many biological activities of pyridine and thiazole derivatives have been reported, including antiviral activity and, more recently, as COVID-19 inhibitors. Thus, in this paper, we designed, synthesized, and characterized a novel series of N-aminothiazole-hydrazineethyl-pyridines, beginning with a N'-(1-(pyridine-3-yl)ethylidene)hydrazinecarbothiohydrazide derivative and various hydrazonoyl chlorides and phenacyl bromides. Their Schiff bases were prepared from the condensation of N-aminothiazole derivatives with 4-methoxybenzaldehyde. FTIR, MS, NMR, and elemental studies were used to identify new products. The binding energy for non-bonding interactions between the ligand (studied compounds) and receptor was determined using molecular docking against the SARS-CoV-2 main protease (PDB code: 6LU7). Finally, the best docked pose with highest binding energy (8a = -8.6 kcal/mol) was selected for further molecular dynamics (MD) simulation studies to verify the outcomes and comprehend the thermodynamic properties of the binding. Through additional in vitro and in vivo research on the newly synthesized chemicals, it is envisaged that the achieved results will represent a significant advancement in the fight against COVID-19.

Synthesis and Molecular Docking of Some Novel 3-Thiazolyl-Coumarins as Inhibitors of VEGFR-2 Kinase.

One crucial strategy for the treatment of breast cancer involves focusing on the Vascular Endothelial Growth Factor Receptor (VEGFR-2) signaling system. Consequently, the development of new (VEGFR-2) inhibitors is of the utmost importance. In this study, novel 3-thiazolhydrazinylcoumarins were designed and synthesized via the reaction of phenylazoacetylcoumarin with various hydrazonoyl halides and α-bromoketones. By using elemental and spectral analysis data (IR, 1H-NMR, 13C-NMR, and Mass), the ascribed structures for all newly synthesized compounds were clarified, and the mechanisms underlying their formation were delineated. The molecular docking studies of the resulting 6-(phenyldiazenyl)-2H-chromen-2-one (3, 6a-e, 10a-c and 12a-c) derivatives were assessed against VEGFR-2 and demonstrated comparable activities to that of Sorafenib (approved medicine) with compounds 6d and 6b showing the highest binding scores (-9.900 and -9.819 kcal/mol, respectively). The cytotoxicity of the most active thiazole derivatives 6d, 6b, 6c, 10c and 10a were investigated for their human breast cancer (MCF-7) cell line and normal cell line LLC-Mk2 using MTT assay and Sorafenib as the reference drug. The results revealed that compounds 6d and 6b exhibited greater anticancer activities (IC50 = 10.5 ± 0.71 and 11.2 ± 0.80 µM, respectively) than the Sorafenib reference drug (IC50 = 5.10 ± 0.49 µM). Therefore, the present study demonstrated that thiazolyl coumarins are potential (VEGFR-2) inhibitors and pave the way for the synthesis of additional libraries based on the reported scaffold, which could eventually lead to the development of efficient treatment for breast cancer.

The pattern of branching and intercommunications of the musculocutaneous nerve for surgical issues: anatomical study.

BACKGROUND: The aim of the present work was to provide evidence about the anatomical variations as regard the origin, distribution, and branching pattern of the musculocutaneous nerve (MCN). MATERIALS AND METHODS: Brachial plexus was dissected in 40 upper limbs of 20 male adult cadavers. The pattern of the MCN was photographed by a digital camera. RESULTS: The location and length of the nerve branches between left and right arms were recorded and statistically analysed. In 90% of specimens the MCN originates from the lateral cord of the brachial plexus, in 5% it arose from the median nerve (MN), while in the remaining 5% specimen, it was absent. The MCN pierced the coracobrachialis muscle in 90% of specimens, and in the remaining 10% did not pierce it. The motor branches to biceps brachii muscle were categorised into: type 1 (90%): one branch that divides to supply the two heads of biceps; type 2 (5%): double branches, innervating each head of biceps separately. The motor branches to brachialis muscle were categorised into: type 1 (82.9%): one branch; type 2 (14.2%): double branches and type 3 (2.9%): three branches that innervating brachialis muscle. Communications between the MCN and the MN were observed in 35% of specimens. CONCLUSIONS: The knowledge of the common and uncommon MCN variations is important especially to the surgeons for carrying out surgical procedures in axilla and arm.

Synthesis, Molecular Docking Study, and Cytotoxicity Evaluation of Some Novel 1,3,4-Thiadiazole as Well as 1,3-Thiazole Derivatives Bearing a Pyridine Moiety.

Pyridine, 1,3,4-thiadiazole, and 1,3-thiazole derivatives have various biological activities, such as antimicrobial, analgesic, anticonvulsant, and antitubercular, as well as other anticipated biological properties, including anticancer activity. The starting 1-(3-cyano-4,6-dimethyl-2-oxopyridin-1(2H)-yl)-3-phenylthiourea (2) was prepared and reacted with various hydrazonoyl halides 3a-h, α-haloketones 5a-d, 3-chloropentane-2,4-dione 7a and ethyl 2-chloro-3-oxobutanoate 7b, which afforded the 3-aryl-5-substituted 1,3,4-thiadiazoles 4a-h, 3-phenyl-4-arylthiazoles 6a-d and the 4-methyl-3- phenyl-5-substituted thiazoles 8a,b, respectively. The structures of the synthesized products were confirmed by spectral data. All of the compounds also showed remarkable anticancer activity against the cell line of human colon carcinoma (HTC-116) as well as hepatocellular carcinoma (HepG-2) compared with the Harmine as a reference under in vitro condition. 1,3,4-Thiadiazole 4h was found to be most promising and an excellent performer against both cancer cell lines (IC50 = 2.03 ± 0.72 and 2.17 ± 0.83 µM, respectively), better than the reference drug (IC50 = 2.40 ± 0.12 and 2.54 ± 0.82 µM, respectively). In order to check the binding modes of the above thiadiazole derivatives, molecular docking studies were performed that established a binding site with EGFR TK.

Synthesis and In Silico Study of Some New bis-[1,3,4]thiadiazolimines and bis-Thiazolimines as Potential Inhibitors for SARS-CoV-2 Main Protease.

A novel series of bis-[1,3,4]thiadiazolimines, and bis-thiazolimines, with alkyl linker, were synthesized through general routes from cyclization of 1,1'-(hexane-1,6-diyl)bis(3-phenylthiourea) and hydrazonoyl halides or α-haloketones, respectively. Docking studies were applied to test the binding affinity of the synthesized products against the Mpro of SARS-CoV-2. The best compound, 5h, has average binding energy (-7.50 ± 0.58 kcal/mol) better than that of the positive controls O6K and N3 (-7.36 ± 0.34 and -6.36 ± 0.31 kcal/mol). Additionally, the docking poses (H-bonds and hydrophobic contacts) of the tested compounds against the Mpro using the PLIP web server were analyzed.

Efficient, Recyclable, and Heterogeneous Base Nanocatalyst for Thiazoles with a Chitosan-Capped Calcium Oxide Nanocomposite.

Calcium oxide (CaO) nanoparticles have recently gained much interest in recent research due to their remarkable catalytic activity in various chemical transformations. In this article, a chitosan calcium oxide nanocomposite was created by the solution casting method under microwave irradiation. The microwave power and heating time were adjusted to 400 watts for 3 min. As it suppresses particle aggregation, the chitosan (CS) biopolymer acted as a metal oxide stabilizer. In this study, we aimed to synthesize, characterize, and investigate the catalytic potency of chitosan-calcium oxide hybrid nanocomposites in several organic transformations. The produced CS-CaO nanocomposite was analyzed by applying different analytical techniques, including Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and field-emission scanning electron microscopy (FESEM). In addition, the calcium content of the nanocomposite film was measured using energy-dispersive X-ray spectroscopy (EDS). Fortunately, the CS-CaO nanocomposite (15 wt%) was demonstrated to be a good heterogeneous base promoter for high-yield thiazole production. Various reaction factors were studied to maximize the conditions of the catalytic technique. High reaction yields, fast reaction times, and mild reaction conditions are all advantages of the used protocol, as is the reusability of the catalyst; it was reused multiple times without a significant loss of potency.