Synthesis and Diuretic Activity of Substituted 1,3,4-Thiadiazoles

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.

Evaluation of Diuretic Activity of Aqueous and Hydro Methanolic Crude Extracts and Solvent Fraction of the Hydromethanolic Flower Extract of Erica Arborea L. (Ericaceae) in Swiss Albino Mice

Purpose

To evaluate the diuretic effects of aqueous (AQ) and hydromethanolic crude extract (HM) the as well as the solvent fractions of the HM extract from Erica arborea flowers in mice.

Methods

Mice were administered AQ and HM crude extracts, along with solvent fractions of HM extracts of E. arborea flowers, including HXF (n-hexane fraction), EAF (ethyl acetate fraction), and AQF (aqueous fraction), at doses ranging from 100 to 400 mg/kg orally. The effects of these extracts and solvent fractions on urine and salt excretion over 5 hours were compared to the effects of the solvent used for reconstitution and a standard drug (furosemide 10 mg/kg), as well as to each other.

Results

The HM crude extract at a lower dose (100 mg/kg) significantly increased urine volume and salt excretion starting from the 3rd h compared to the AQ crude extract. Similar effects were observed for EAF. Notably, the HM extract and its EAF at 400 mg/kg showed comparable urine and salt excretion profiles to the standard drug.

Conclusion

This study demonstrated that HM extract and EAF promote better diuresis, likely due to their saluretic properties. Furthermore, it confirms the diuretic activity of Erica arborea flowers.

New N-(1,3,4-thiadiazole-2-yl)acetamide derivatives as human carbonic anhydrase I and II and acetylcholinesterase inhibitors

Various carbonic anhydrase (CA) enzyme isoforms are known today. In addition to the use of CA inhibitors as diuretics, antiepileptics and antiglaucoma agents, the inhibition of other specific isoforms of CA was reported to have clinical benefits in cancers. In this study, two groups of 1,3,4-thiadiazole derivatives were designed and synthesized to act as human CA I and II (hCA I and hCA II) inhibitors. The activities of these compounds were tested in vitro and evaluated in silico studies. The activity of the synthesized compounds was also tested against acetylcholinesterase (AChE) to evaluate the relation of the newly designed structures to the activity against AChE. The synthesized compounds were analyzed by 1H NMR,13C NMR and high-resolution mass spectroscopy (HRMS). The results displayed a better activity of all the synthesized compounds against hCA I than that of the commonly used standard drug, Acetazolamide (AAZ). The compounds also showed better activity against hCA II, except for compounds 5b and 6b. Only compounds 6a and 6c showed superior activity against AChE compared to the standard agent, tacrine (THA). In silico studies, including absorption, distribution, metabolism and excretion (ADME) and drug-likeness evaluation, molecular docking, molecular dynamic simulations (MDSs) and density functional theory (DFT) calculations, were compatible with the in vitro results and presented details regarding the structure-activity relationship.Communicated by Ramaswamy H. Sarma.

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.

2-Substituted-3-(5-Substituted-1,3,4-oxadiazol/thiadiazol-2-yl) Thiazolidin-4-one Derivatives: Synthesis, Anticancer, Antimicrobial, and Antioxidant Potential

In this innovative research, a novel series of thiazolidin-4-one analogues having a 1,3,4-oxadiazole/thiadiazole moiety were derived and the structures of all the newly obtained molecules were established using different physicochemical and analytical means (¹H-NMR, FTIR, mass spectra, and elemental analyses). The synthesized molecules were then investigated for their antiproliferative, antimicrobial, and antioxidant potential. The cytotoxicity screening studies revealed that analogues D-1, D-6, D-15, and D-16 possessed comparable efficacy, within the IC₅₀ range (1 to 7 μM), when taking doxorubicin as a reference drug (IC₅₀ = 0.5 μM). The antimicrobial activity was assessed using different Gram-(+) and Gram-(-) bacterial and fungal strains and the results revealed that molecules D-2, D-4, D-6, D-19, and D-20 possessed potent activity against selective strains of microbes with MIC ranges of 3.58 to 8.74 µM. The antioxidant evaluation was performed using the DPPH assay and the screening results revealed that analogue D-16 was the most potent derivative (IC₅₀ = 22.3 µM) when compared with the positive control, ascorbic acid (IC₅₀ = 111.6 µM). Structure-activity relationship (SAR) studies of the synthesized novel derivatives revealed that para-substituted halogen and hydroxy derivatives have remarkable potential against the MCF-7 cancer cell line and antioxidant potential. Similarly, electron-withdrawing groups (Cl/NO₂) and -donating groups at the para position possess moderate to promising antimicrobial potential.

Diverse Biological Activities of 1,3,4-Thiadiazole Scaffold

The chemistry of 1,3,4-thiadiazole is one of the most interesting scaffolds for synthesizing new drug molecules due to their numerous pharmacological activities. Several modifications in the thiadiazole ring have been made, proving it to be more potent and highly effective with a less toxic scaffold for various biological activities. There are several marketed drugs containing 1,3,4-thiadiazole ring in their structure. In this review article, we have tried to compile the newly synthesized 1,3,4-thiadiazole derivatives possessing important pharmaceutical significance since 2014.