Synthesis, Structural Stability Calculation, and Antibacterial Evaluation of Novel 3,5-Diphenylcyclohex-2-en-1-one Derivatives

Synthesis, docking and characterization of some novel 5-(S-alkyl)-1.3.4-thiadiazole-2-carboxamide derivatives as anti-inflammatory and antibacterial agents

Because of the great pharmacological and industrial significance of 1,3,4-thiadiazole and its related compounds, researchers are still very interested in them. For this reason, in this study, we looked at ways to create new hybrid compounds containing carboxamide and 1,3,4-thiadiazole moieties. The thioxoacetamide derivatives used to make these compounds were reacted with various alkylated reagents to produce multiple S-alkyl groups. Additionally, these compounds were reacted with aldehydes to form novel derivatives known as 5-(substituent)-N-phenyl-1,3,4-thiadiazole-2-carboxamide. Here, we used the agar well diffusion method to examine the antibacterial activity of all the produced compounds against a few pathogenic bacteria that were resistant to multiple drugs. Additionally, look into their capacity to lower inflammation through the use of bovine serum albumin in the protein denaturation procedure. The substances were characterized by spectral analysis (IR, 1HNMR, 13CNMR and Elemental Analysis), and efficient as antibacterial agents against all the tested bacterial strains, except for Escherichia coli. Compounds 4a and 8c showed the highest level of inhibition zone against Gram-positive bacteria (Staph. aureus, Bacillus subtilis) at concentration 0.3, 0.4 and 0.5 mg/ml compared with ciprofloxacin at the same concentrations. The results demonstrated that every compound has significant anti-inflammatory activity. At a concentration of 250 µg/ml, compounds 3a, 4c and 8c had the highest percentage inhibition of protein denaturation when (83.24%, 86.44% and 85.14%, respectively) compared to other compounds and diclofenac sodium as reference drug. Comparing compounds 4c and 8c to ciprofloxacin and diclofenac sodium, they showed powerful antibacterial and anti-inflammatory action. Furthermore, an investigation using molecular docking against DHPS from S. aureus (PDB ID: 6CLV) showed a strong connection with the intended protein and an elevated docking score, making it a prime candidate for antibiotics.

Synthesis, docking and biological evaluation of purine-5-N-isosteresas anti-inflammatory agents

An operationally simple one-pot three-component and convenient synthesis method for a series of diverse purine analogues of 5-amino-7-(substituted)-N-(4-sulfamoylphenyl)-4,7-dihydro-[1,2,4]-triazolo[1,5-a][1,3,5]triazine-2-carboxamide derivatives generated in situ via the reaction of 2-hydrazinyl-N-(4-sulfamoylphenyl)-2-thioxoacetamide, cyanoguanidine and a variety of aldehydes was achieved under green conditions. This experiment was conducted to evaluate the anti-inflammatory effect of the newly synthesized compounds using indomethacin as a reference medication; all compounds were tested for in vitro anti-inflammatory activity using the inhibition of albumin denaturation, RBC hemolysis technique and COX inhibition assay. The results showed that all evaluated compounds exhibited significant in vitro anti-inflammatory efficacy leading to excellently effective RBC membrane stabilization, inhibition of protein denaturation, and inhibition of COX enzymes when compared to those of indomethacin. At concentrations of 50, 100, 200, and 300 μg ml-1, these compounds decreased COX-1 and COX-2 activities more than indomethacin and have IC50 values in the range of 40.04-87.29 μg ml-1 for COX-1 and 27.76-42.3 μg ml-1 for COX-2 while indomethacin showed IC50 = 91.57 for COX-1 and 42.66 μg ml-1 for COX-2. The anti-inflammatory findings show the need for more investigation to define the properties underlying the evaluated compounds' anti-inflammatory abilities. The enzyme cyclooxygenase-2 (COX 2) (PDB ID: 5IKT) was docked with ten synthetic substances. With docking scores (S) of -8.82, -7.82, and -7.76 kcal mol-1, 7-furan triazolo-triazine (4), 7-(2-hydroxy phenyl) triazolo-triazine (11), and 7-(4-dimethylamino phenyl) triazolo-triazine (12) had the greatest binding affinities, respectively. Therefore, these substances have COX-2 (PDB ID: 5IKT) inhibitory capabilities and hence may be investigated for COX 2 targeting development. Furthermore, both the top-ranked compounds (4 and 11) and the standard indomethacin were subjected to DFT analysis. The HOMO - LUMO energy difference (ΔE) of the mentioned compounds was found to be less than that of indomethacin.

Thiadiazole/Thiadiazine Derivatives as Insecticidal Agent: Design, Synthesis, and Biological Assessment of 1,3,4-(Thiadiazine/Thiadiazole)-Benzenesulfonamide Derivatives as IGRs Analogues against Spodoptera littoralis

In keeping with our investigation, a simple and practical synthesis of novel heterocyclic compounds with a sulfamoyl moiety that can be employed as insecticidal agents was reported. The compound 2-hydrazinyl-N-(4-sulfamoylphenyl)-2-thioxoacetamide 1 was coupled smoothly with triethylorthoformate or a variety of halo compounds, namely phenacyl chloride, chloroacetyl chloride, chloroacetaldehyde, chloroacetone, 1,3-dichloropropane, 1,2-dichloroethane, ethyl chloroformate, 2,3-dichloro-1,4-naphthoquinone, and chloroanil respectively, which afforded the 1,3,4-thiadiazole and 1,3,4-thiadiazine derivatives. The new products structure was determined using elemental and spectral analysis. Under laboratory conditions, the biological and toxicological effects of the synthetic compounds were also evaluated as insecticides against Spodoptera littoralis (Boisd.). Compounds 3 and 5 had LC50 values of 6.42 and 6.90 mg/L, respectively. The investigated compounds (from 2 to 11) had been undergoing molecular docking investigation for prediction of the optimal arrangement and strength of binding between the ligand (herein, the investigated compounds (from 2 to 11)) and a receptor (herein, the 2CH5) molecule. The binding affinity within docking score (S, kcal/mol) ranged between -8.23 (for compound 5), -8.12 (for compound 3) and -8.03 (for compound 9) to -6.01 (for compound 8). These compounds were shown to have a variety of binding interactions within the 2CH5 active site, as evidenced by protein-ligand docking configurations. This study gives evidence that those compounds have 2CH5-inhibitory capabilities and hence may be used for 2CH5-targeting development. Furthermore, the three top-ranked compounds (5, 3, and 9) and the standard buprofezin were subjected to density functional theory (DFT) analysis. The highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) energy difference (ΔE) of compounds 5, 3, and 9 was found to be comparable to that of buprofezin. These findings highlighted the potential and relevance of charge transfer at the molecular level.

An efficient eco-friendly, simple, and green synthesis of some new spiro-N-(4-sulfamoyl-phenyl)-1,3,4-thiadiazole-2-carboxamide derivatives as potential inhibitors of SARS-CoV-2 proteases: drug-likeness, pharmacophore, molecular docking, and DFT exploration

INTRODUCTION

The coronavirus disease 2019 (COVID-19) pandemic has caused a global health crisis. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly contagious virus that can cause severe respiratory illness. There is no specific treatment for COVID-19, and the development of new drugs is urgently needed.

PROBLEM STATEMENT

The SARS-CoV-2 main protease (Mpro) enzyme is a critical viral enzyme that plays a vital role in viral replication. The inhibition of Mpro enzyme can be an effective strategy for developing new COVID-19 drugs.

METHODOLOGY

An efficient operationally simple and convenient green synthesis method had been done towards a series of novel spiro-N-(4-sulfamoylphenyl)-2-carboxamide derivatives, in ethanol at room temperature in green conditions, up to 90% yield. The molecular structures of the synthesized compounds were verified using spectroscopic methods.The title compounds were subjected to in silico analysis, including Lipinski's rule and ADMET prediction, in addition to pharmacophore modeling and molecular docking against the active site of SARS-CoV-2 target main protease (Mpro) enzyme (6LU7). Furthermore, both of the top-ranked compounds (5 and 6) and the standard Nirmatrelvir were subjected to DFT analysis.

FINDINGS

The synthesized compounds exhibited good binding affinity to SARS-CoV-2 Mpro enzyme, with binding energy scores ranging from - 7.33 kcal/mol (compound 6) and - 7.22kcal/mol (compound 5) to - 6.54 kcal/mol (compounds 8 and 9). The top-ranked compounds (5 and 6) had lower HOMO-LUMO energy difference (ΔE) than the standard drug Nirmatrelvir. This highlights the potential and relevance of charge transfer at the molecular level.

RECOMMENDATION

These findings suggest that the synthesized spiro-N-(4-sulfamoylphenyl)-2-carboxamide derivatives could be potential candidates for COVID-19 drug development. To confirm these drugs' antiviral efficacy in vivo, more research is required. With very little possibility of failure, this proven method could aid in the search for the SARS-CoV-2 pandemic's desperately needed medications.

Green synthesis, biological and molecular docking of some novel sulfonamide thiadiazole derivatives as potential insecticidal against Spodoptera littoralis

Although crop plants provide the majority of human food, pests and insects frequently cause huge economic losses. In order to develop innovative insecticidal compounds with low toxicity and a positive environmental impact, we developed new N-(4-sulfamoylphenyl)-1,3,4-thiadiazole-2-carboxamide derivatives (2-12). With the use of spectroscopic techniques and elemental data, the chemical structure of these new compounds was meticulously clarified. The toxicological and biological effects of the synthesized compound of the cotton leafworm Spodoptera littoralis (Boisduval, 1833) under laboratory conditions were also investigated. Regarding the determined LC50 values, compounds 3, 7, 8, and 10 showed the most potent toxic effect with LC50 values of 29.60, 30.06, 27.65 and 29.01 ppm, respectively. A molecular docking investigation of twelve synthetic compounds (from compound 2 to compound 12) was performed against AChE (Acetylcholinesterase). There was a wide range of binding affinities shown by these compounds. This work suggests that these substances may have insecticidal and AChE inhibitory properties, and it may be possible to further explore them in the process of creating pesticides that target AChE.

Unravelling the synthetic and therapeutic aspects of five, six and fused heterocycles using Vilsmeier-Haack reagent

The aim of this review is to encapsulate the synthetic protocols and medicinal aspects of a wide range of heterocyclic compounds using the Vilsmeier-Haack (V. H.) reagent. These derivatives act as excellent precursors having different aryl ring functionalities and could be used for the synthesis of a variety of heterocyclic scaffolds. The V. H. reagent, a versatile reagent in organic chemistry, is used to formylate various heterocyclic compounds of medicinal interest. Due to the different chemical interactions, efficacy, and potency of V. H. reagents, plenty of heterocyclic compounds can be synthesized which serve as a constituent in various novel medications and acts as a bridge between biology and chemistry. These carboxylate moieties can effectively cooperate as precursors for several multi-component reactions (MCR) including Strecker synthesis, Bucherer-Berg reaction and post-MCR cyclization, modified variants with various pharmaceutical applications such as anti-tumor, anti-convulsant, anti-chitosomal and so on.

Novel 2-Acetamido-2-ylidene-4-imidazole Derivatives (El-Saghier Reaction): Green Synthesis, Biological Assessment, and Molecular Docking

El-Saghier reaction is the novel, general, and green reaction of various amines with ethyl cyanoacetate and ethyl glycinate hydrochloride. A new series of imidazolidin-4-ones and bis-N-(alkyl/aryl) imidazolidin-4-ones was synthesized in a sequential, one-pot procedure under neat conditions for 2 h at 70 °C. Excellent high yields (90-98%) were achieved in a short period of time while avoiding issues related to the hazardous solvents utilized (cost, safety, and pollution). The spectrum analyses and elemental data of the newly synthesized compounds helped us to clarify their structures. The obtained compounds were tested for antibacterial activity in vitro and compared to the standard antibiotic chloramphenicol as the standard, measuring the inhibition zone (nm) and activity index (%). With an antibacterial percentage value of 80.0 against Escherichia coli, N,N'-(propane-1,3-diyl) bis(2-(4-oxo-4,5-dihydro-1H-imidazole-2-yl) acetamide) proved to be the most effective. Antimicrobial activity was confirmed by a molecular docking investigation to investigate how chemicals bind to the bacterial FabH-CoA complex in E. coli (PDB ID: 1HNJ).