2-Amino-1,3,4-thiadiazole as a potential scaffold for promising antimicrobial agents

Recent advances in the synthesis of antidepressant derivatives: pharmacologic insights for mood disorders

Mood disorders, including depression, remain a significant global health concern, necessitating continuous efforts to develop novel and more effective antidepressant therapies. Although there have been significant advancements in comprehending the biology of Major Depressive Disorder (MDD), a considerable number of people suffering from depression do not exhibit positive responses to the pharmacologic treatments now available. This study specifically examines emerging targets and potential future approaches for pharmaceutical interventions in the treatment of MDD. The discussion revolves around novel therapeutic agents and their effectiveness in treating depression. The focus is on the specific pathophysiological pathways targeted by these agents and the amount of evidence supporting their use. While conventional antidepressants are anticipated to continue being the primary treatment for MDD in the foreseeable future, there is currently extensive research being conducted on numerous new compounds to determine their effectiveness in treating MDD. Many of these compounds have shown encouraging results. This review highlighted the recent advances in the synthesis of antidepressant derivatives and explores their pharmacologic insights for the treatment of mood disorders.

Multitarget Pharmacology of Sulfur-Nitrogen Heterocycles: Anticancer and Antioxidant Perspectives

Cancer and oxidative stress are interrelated, with reactive oxygen species (ROS) playing crucial roles in physiological processes and oncogenesis. Excessive ROS levels can induce DNA damage, leading to cancer, and disrupt antioxidant defenses, contributing to diseases like diabetes and cardiovascular disorders. Antioxidant mechanisms include enzymes and small molecules that mitigate ROS damage. However, cancer cells often exploit oxidative conditions to evade apoptosis and promote tumor growth. Antioxidant therapy has shown mixed results, with timing and cancer-type influencing outcomes. Multifunctional drugs targeting multiple pathways offer a promising approach, reducing side effects and improving efficacy. Recent research focuses on sulfur-nitrogen heterocyclic derivatives for their dual antioxidant and anticancer properties, potentially enhancing therapeutic efficacy in oncology. The newly synthesized compounds often do not demonstrate both antioxidant and anticancer properties simultaneously. Heterocyclic rings are typically combined with phenyl groups, where hydroxy substitutions enhance antioxidant activity. On the other hand, electron-withdrawing substituents, particularly at the p-position on the phenyl ring, tend to enhance anticancer activity.

New Antibacterial 1,3,4-Thiadiazole Derivatives With Pyridine Moiety

1,3,4-Thiadiazole compounds were synthesized using pyridine carboxylic acid derivatives and thiosemicarbazide derivatives. The molecular structures of the resulting compounds were characterized by spectroscopic methods such as ATR-FTIR, 1H-NMR, and elemental analysis. Its compounds were also examined for their antibacterial properties against some strains of bacteria. Five synthesized compounds showed varying antibacterial effects on Escherichia coli, Salmonella kentucky, Bacillus substilis and Klebsiella pneumoniae. This result revealed that some of the resulting compounds could be antibacterial agents.

Functionalization of 2-Mercapto-5-methyl-1,3,4-thiadiazole: 2-(ω-Haloalkylthio) Thiadiazoles vs. Symmetrical Bis-Thiadiazoles

A study on the functionalisation of 2-mercapto-5-methyl-1,3,4-thiadiazole has been conducted, yielding two series of products: 2-(ω-haloalkylthio)thiadiazoles and symmetrical bis-thiadiazoles, with variable chain lengths. The experimental conditions were optimised for each class of compounds by altering the base used and the reagents' proportions, leading to the development of separate protocols tailored to their specific reactivity and purification needs. The target halogenide reagents and bis-thiadiazole ligands were obtained either as single products or as mixtures easily separable by chromatography. Characterisation of the products was performed using 1D and 2D NMR spectra in solution, complemented by single crystal X-ray diffraction (XRD) for selected samples, to elucidate their structural properties.

Air-Stable and Eco-Friendly Symmetrical Imine with Thiadiazole Moieties in Neutral and Protonated form for Perovskite Photovoltaics

This paper proposes molecular and supramolecular concepts for potential application in perovskite solar cells. New air-stable symmetrical imine, with thiadiazole moieties PPL2: (5E,6E)-N2,N5-bis(4-(diphenylamino)benzylidene)-1,3,4-thiadiazole-2,5-diamine), as a hole-transporting material was synthesised in a single-step reaction, starting with commercially available and relatively inexpensive reagents, resulting in a reduction in the cost of the final product compared to Spiro-OMeTAD. Moreover, camphorsulfonic acid (CSA) in both enantiomeric forms was used to change the HOMO-LUMO levels and electric properties of the investigated imine-forming complexes. Electric, optical, thermal, and structural studies of the imine and its complexes with CSA were carried out to characterise the new material. Imine and imine/CSA complexes were also characterised in depth by the proton Nuclear Magnetic Resonance 1H NMR method. The position of nitrogen in the thidiazole ring influences the basicity of donor centres, which results in protonation in the imine bond. Simple devices of ITO/imine (with or without CSA(-) or CSA(+))/Ag/ITO architecture were constructed, and a thermographic camera was used to find the defects in the created devices. Electric behaviour was also studied to demonstrate conductivity properties under the forward current. Finally, the electrical properties of imine and its protonated form with CSA were compared with Spiro-OMeTAD. In general, the analysis of thermal images showed a very similar response of the samples to the applied potential in terms of the homogeneity of the formed organic layer. The TGA analysis showed that the investigated imine exhibits good thermal stability in air and argon atmospheres.

Emerging synthetic strategies and pharmacological insights of 1,3,4-thiadiazole derivatives: a comprehensive review

This review meticulously examines the synthesis techniques for 1,3,4-thiadiazole derivatives, focusing on cyclization, condensation reactions and functional group transformations. It enhances the understanding of these chemical methods that re crucial for tailoring derivative properties and functionalities. This study is considered to be vital for researchers, detailing established effects such as antioxidant, antimicrobial and anticancer activities, and revealing emerging pharmacological potentials such as neuroprotective, antiviral and antidiabetic properties. It also discusses the molecular mechanisms underlying these effects. In addition, this article covers structure-activity relationship studies and computational modelling that are essential for designing potent, selective 1,3,4-thiadiazole compounds. This work lays a foundation for future research and targeted therapeutic development.

Synthesis of tetrazole hybridized with thiazole, thiophene or thiadiazole derivatives, molecular modelling and antimicrobial activity

Background

Tetrazole-based derivatives and their electronic structures have displayed interesting antimicrobial activity.

Methods

The tetrazole-based hybrids linked with thiazole, thiophene and thiadiazole ring systems have been synthesized through various chemical reactions. The computational method DFT/B3LYP has been utilized to calculate their electronic properties. The antimicrobial effectiveness was investigated against representative bacterial and fungal strains. Additionally, the synthesized derivatives binding interaction was stimulated by docking program against PDB ID: 4URO as a model of the ATP binding domain of S. aureus DNA Gyrase subunit B.

Results

The structures of the synthesized tetrazole-based derivatives were confirmed by IR, NMR, and Mass spectroscopic data. The DFT/B3LYP method showed that the thiadiazole derivatives 9a-c had lower ΔEH-L than the thiophenes 7a-c and thiazoles 5a-c. The hybrids 5b, 5c, and 7b exhibited proper antibacterial activity against Gram's +ve bacterial strains (S. aureus and S. pneumonia), while 9a displayed potent activity towards Gram's -ve bacterial strains (S. typhimurium and E. coli). Meanwhile, derivatives 5a-b, 7a, 7c, and 9c showed good effectiveness towards fungal strain (C. albicans).

Conclusion

The study provides valuable tetrazole core-linked heterocyclic rings and opens the door to further research on their electrical characteristics and applications. Tetrazoles and thiazoles have antibacterial properties in pharmacological frameworks, making these hybrids potential lead molecules for drug development. The conclusion summarizes the data and suggests that the synthesized chemicals' interaction with a particular protein domain suggests focused biological activity.

New 1,3,4-Thiadiazole Derivatives as α-Glucosidase Inhibitors: Design, Synthesis, DFT, ADME, and In Vitro Enzymatic Studies

Diabetes is an emerging disorder in the world and is caused due to the imbalance of insulin production as well as serious effects on the body. In search of a better treatment for diabetes, we designed a novel class of 1,3,4-thiadiazole-bearing Schiff base analogues and assessed them for the α-glucosidase enzyme. In the series (1-12), compounds are synthesized and 3 analogues showed excellent inhibitory activity against α-glucosidase enzymes in the range of IC50 values of 18.10 ± 0.20 to 1.10 ± 0.10 μM. In this series, analogues 4, 8, and 9 show remarkable inhibition profile IC50 2.20 ± 0.10, 1.10 ± 0.10, and 1.30 ± 0.10 μM by using acarbose as a standard, whose IC50 is 11.50 ± 0.30 μM. The structure of the synthesized compounds was confirmed through various spectroscopic techniques, such as NMR and HREI-MS. Additionally, molecular docking, pharmacokinetics, cytotoxic evaluation, and density functional theory study were performed to investigate their behavior.

Thiadiazole and Thiazole Derivatives as Potential Antimicrobial Agents

BACKGROUND

This review summarizes data on heterocyclic systems with thiadiazole and thiazole fragments in molecules as promising antimicrobial agents.

INTRODUCTION

Thiadiazole and thiazole backbones are the most favored and well-known heterocycles, a common and essential feature of various drugs. These scaffolds occupy a central position and are the main structural components of numerous drugs with a wide spectrum of action. These include antimicrobial, antituberculous, anti-inflammatory, analgesic, antiepileptic, antiviral, and anticancer agents.

METHOD

The research is based on bibliosemantic and analytical methods using bibliographic and abstract databases, as well as databases of chemical compounds.

RESULT

This review reports on thiadiazole and thiazole derivatives, which have important pharmacological properties. We are reviewing the structural modifications of various thiadiazole and thiazole derivatives, more specifically, the antimicrobial activity reported over the last years, as we have taken this as our main research area. 80 compounds were illustrated, and various derivatives containing hydrazone bridged thiazole and pyrrole rings, 2-pyridine and 4-pyridine substituted thiazole derivatives, compounds containing di-, tri- and tetrathiazole moieties, spiro-substituted 4- thiazolidinone-imidazoline-pyridines were analyzed. Derivatives of 5-heteroarylidene-2,4- thiazolidinediones, fluoroquinolone-thiadiazole hybrids, and others.

CONCLUSION

1,3,4-thiadiazoles and thiazoles are valuable resource for researchers engaged in rational drug design and development in this area.

Synthesis of 1,3,4-Thiadiazole Derivatives and Their Anticancer Evaluation

Thiadiazole derivatives have garnered significant attention in the field of medicinal chemistry due to their diverse pharmacological activities, including anticancer properties. This article presents the synthesis of a series of thiadiazole derivatives and investigates their chemical characterization and potential anticancer effects on various cell lines. The results of the nuclear magnetic resonance (NMR) analyses confirmed the successful formation of the target compounds. The anticancer potential was evaluated through in silico and in vitro cell-based assays using LoVo and MCF-7 cancer lines. The assays included cell viability, proliferation, apoptosis, and cell cycle analysis to assess the compounds' effects on cancer cell growth and survival. Daphnia magna was used as an invertebrate model for the toxicity evaluation of the compounds. The results revealed promising anticancer activity for several of the synthesized derivatives, suggesting their potential as lead compounds for further drug development. The novel compound 2g, 5-[2-(benzenesulfonylmethyl)phenyl]-1,3,4-thiadiazol-2-amine, demonstrated good anti-proliferative effects, exhibiting an IC50 value of 2.44 µM against LoVo and 23.29 µM against MCF-7 after a 48-h incubation and little toxic effects in the Daphnia test.

Synthesis, biological and molecular modelling for 1,3,4-thiadiazole sulfonyl thioureas: bacterial and fungal activity

Some substituted thioureas (6a-i) containing a 1,3,4-thiadiazole ring were synthesized by the reaction of the corresponding substituted 2-amino-1,3,4-thiadiazoles 3a-i with p-toluenesulfonyl isocyanate in a one-pot procedure. The antibacterial and antifungal activities of these sulfonyl thioureas were estimated using a minimum inhibitory concentration protocol. Almost all the thioureas exhibited remarkable antimicrobial activity. Amongst the studied compounds, thioureas 6a, 6c, 6h, and 6i were better inhibitors against the bacterium S. aureus, with MIC values of 0.78-3.125 μg mL-1. These compounds were also tested for their inhibition against S. aureus enzymes, including enzymes of DNA gyrase, DNA topoisomerase IV (Topo IV), and dihydrofolate reductase. Amongst the compounds, 6h was a strong inhibitor, with IC50 values of 1.22, 53.78, and 0.23, respectively. Induced fit docking calculations were performed to observe the binding efficiency and steric interactions of these compounds. The obtained results showed that compound 6h was compatible with the active sites of S. aureus DNA gyrase 2XCS. This ligand interacted with residues ASP1083 (chain D), MET1121 (chain B), ARG1122 (chain D), and also with HOH2035, HOH2089, HOH2110, HOH2162. Molecular dynamics simulation in a water solvent system showed that the active interactions with residues ASP083 and MET1121 (chain B), along with ASP1083, MET1121, and ARG1122 (chain D), played an important role in stabilizing complex 6h/2XCS in the active pocket.

Synthesis, biological evaluation and in silico studies of some new analogues of 3,5-vdisubstituted thiazolidin-2,4-dione

Background: A new series of 3,5-disubstituted thiazolidin-2,4-dione molecules were derived and characterized using various spectral techniques (1H NMR, IR, carbon, hydrogen, nitrogen, etc.) and physicochemical parameters. Materials & methods: The molecules were derived using Knoevenagel condensation followed by Mannich reaction and further synthesized analogues were screened for their antioxidant and antimicrobial potential using 2,2-diphenyl-1-picrylhydrazyl free radical scavenging method and serial tube dilution method, respectively, along with in silico studies (docking and absorption, distribution, metabolism and excretion parameters) to explore the drug-receptor interaction and druglikeness. Results & conclusion: In antimicrobial screening, the analogs MP2, MM6, MM7 and MM8 displayed promising activity while molecule MM4 exhibited better antioxidant potential in the series. In molecular docking analysis, the best-fitted analogs, namely, MM6 and MM7, showed good interactions.

Synthesis and crystal structure studies of 5-(tri-fluoro-meth-yl)-1,3,4-thia-diazol-2(3H)-one at 180 K

The synthesis and crystal structure of C3HF3N2OS, systematic name 5-(tri-fluoro-meth-yl)-1,3,4-thia-diazol-2(3H)-one (5-TMD-2-one), a compound containing the pharmacologically important heterocycle 1,3,4-thia-diazole, is presented. The asymmetric unit comprises six independent mol-ecules (Z' = 6), all of which are planar. The r.m.s. deviations from each mean plane range from 0.0063 to 0.0381 Å, not including the CF3 fluorine atoms. Within the crystal, two of the mol-ecules form hydrogen-bonded dimers that in turn combine with inversion-related copies to form tetra-meric constructs. Similar tetra-mers, but lacking inversion symmetry, are formed by the remaining four mol-ecules. The tetra-mers are linked into tape-like motifs by S⋯O and O⋯O close contacts. The environments of each symmetry-independent mol-ecule were compared via a Hirshfeld surface analysis. The most abundant atom-atom contacts are between fluorine atoms, while the strongest result from N-H⋯O hydrogen bonds.

Thiadiazole – A promising structure in design and development of anti-Alzheimer agents

The design and development of effective multitargeted agents in treating Alzheimer disease (AD) has always been a hot topic in the field of drug discovery. Since AD is a multifactorial disorder, various key hidden players such as deficit of acetylcholine (ACh), tau-protein aggregation, and oxidative stress have been associated with the incidence and progress of AD. In pursuit of improving efficacy and expanding the range of pharmacological activities of current AD drugs, the molecular hybridization method is also used intensively. Five-membered heterocyclic systems such as thiadiazole scaffolds have previously been shown to have therapeutic activity. Thiadiazole analogs as an anti-oxidant compound have been known to include a wide range of biological activity from anti-cancer to anti-Alzheimer properties. The suitable pharmacokinetic and physicochemical properties of the thiadiazole scaffold have introduced it as a therapeutic target in medicinal chemistry. The current review portrays the critical role of the thiadiazole scaffold in the design of various compounds with potential effects in the treatment of Alzheimer's disease. Furthermore, the rationale used behind hybrid-based design strategies and the outcomes achieved through the hybridization of Thiadiazole analogs with various core structures have been discussed. In addition, the data in the present review may help researchers in the design of new multidrug combinations that may provide new options for the treatment of AD.

Design, Synthesis, Biological Activity Evaluation and Action Mechanism of Myricetin Derivatives Containing Thiazolebisamide

The plant diseases caused by a variety of pathogens such as viruses, bacteria and fungi pose a great threat to global food production and food safety. Therefore, the search for green, efficient and pollution-free pesticides has become an important task. In this article, 23 myricetin derivatives containing thiazolebisamides active groups have been designed and synthesized. Their activities were evaluated by performing in vitro antibacterial and in vivo antiviral assays, microscale thermophoresis (MST) and molecular docking assays. The results of in vivo antiviral assays showed that compounds A4 and A23 exhibited good antiviral activity with EC50 values of 79.0 and 54.1 μg/mL for therapeutic activity and 103.3 and 91.2 μg/mL for protective activity, respectively. The dissociation constants (Kd) values of compounds A4 and A23 against TMV-CP were 0.021 and 0.018 μM, respectively, determined by microscale thermophoresis (MST), which were much smaller than those of the commercial drug ningnanmycin (NNM), which were 2.84 μM. The interaction of compounds A4, A23 with TMV-CP was further verified at the molecular level. In addition, in vitro antifungal assays of this series of compounds showed that they exhibited some inhibitory activity against a variety of fungi, especially against the phytophthora capsici. Among them, A13 and A20 showed similar inhibitory activity to the control drug azoxystrobin at 100 μg/mL against the phytophthora capsici.

Current scenario of quinolone hybrids with potential antibacterial activity against ESKAPE pathogens

The ESKAPE (Escherichia coli/E. coli, Staphylococcus aureus/S. aureus, Klebsiella pneumonia/K. pneumoniae, Acinetobacter Baumannii/A. baumannii, Pseudomonas aeroginosa/P. aeroginosa and Enterobacter spp.) pathogens, which could escape or evade common therapies through diverse antimicrobial resistance mechanisms and biofilm formation, are deemed as highly virulent bacteria responsible for life-threatening diseases, calling for novel chemotherapeutics. Quinolones including 2-quinolones and 4-quinolones have occupied a propitious place in drug design and development due to their excellent pharmacological profiles. Quinolones especially fluoroquinolones could inhibit the synthesis of nucleic acid of ESKAPE pathogens, leading to the rupture of bacterial chromosome. However, the resistance of ESKAPE pathogens to quinolones develops rapidly and spreads widely. Accordingly, it has become increasingly urgent to enhance the potency of quinolones against both drug-susceptible and drug-resistant ESKAPE pathogens. Quinolone hybrids can bind with different drug targets simultaneously and have been considered as useful prototypes to circumvent drug resistance. The purpose of this review is to summarize the current scenario (2018-present) of quinolone hybrids with potential antibacterial activity against ESKAPE pathogens, together with the structure-activity relationships and mechanisms of action to facilitate further rational design of more effective candidates.

Synthesis and Biological Evaluation of Novel Thiadiazole Derivatives as Antiplatelet Agents

A novel series of thiadiazole compounds was synthesized through the reaction of thiosemicarbazone intermediates with 2, 3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The antiplatelet activity of the synthesized compounds was evaluated using an aggregation test with adenosine diphosphate (ADP) and arachidonic acid (AA) as platelet aggregation inducers. Among the synthesized analogs, compound 3b exhibited the most potent inhibition of platelet aggregation induced by ADP (half maximal inhibitory concentration [IC50] = 39 ± 11 µM). Molecular docking studies of 3b revealed hydrogen bonds between the nitrogen of the thiadiazole ring and Lys280. The tolyl ring exhibited hydrophobic interactions with Tyr105, similar to the antagonist co-crystallized with P2Y12 (PDB ID: 4NTJ). These compounds have the potential to serve as lead molecules for designing P2Y12 inhibitors.

Theoretical model study of adsorbed antimalarial-graphene dimers: doping effects, photophysical parameters, intermolecular interactions, edge adsorption, and SERS

Future diagnostics and therapy applications are in part riding on the discovery and implementation of new optical techniques and strategies (which often derive from dyads) for example, prediction of features in surface-enhanced Raman spectroscopy requires the study of chromophore-chromophore interactions involve intermolecular forces, drug delivery, and photo mechanisms which are of great interest. New matches between chromophore systems (i.e. FRET), and π-delocalized surfaces are important to study. We explore low-molecular weight drug molecules and their interaction with the reporter material/surface of graphene. Bonding, charge transfer and orbital interactions for 2-amino-5-(1-methyl-5-nitro-2-imidazolyl)-1,3,4-thiadiazole (megazol or AMIT) on graphene were carried out. The graphene model substrate was monotonically/monatomically substituted (doped) with one neutral heteroatom (N/O/S/B) in place of one carbon center; chemical adsorption of AMIT is due to charge transfer from doped graphene to AMIT (DFT). Our AMIT-nanocluster studies show that the nanoclusters will act as a sensor component for the detection of drugs due to SERS. Our findings identified that the greater the energy of the charge transfer, the stronger the calculated chemical adsorption. Additionally, charge transfer is highest for the N-doped systems and least for pristine graphene, resulting in a stronger adsorption energy for N-doped graphene. Mulliken charge analysis of structures confirms enhancement found in QD-AMIT systems.Communicated by Ramaswamy H. Sarma.

Identification of 2-Aminoacyl-1,3,4-thiadiazoles as Prostaglandin E2 and Leukotriene Biosynthesis Inhibitors

The application of a multi-step scientific workflow revealed an unprecedented class of PGE₂/leukotriene biosynthesis inhibitors with in vivo activity. Specifically, starting from a combinatorial virtual library of ∼4.2 × 10⁵ molecules, a small set of compounds was identified for the synthesis. Among these, four novel 2-aminoacyl-1,3,4-thiadiazole derivatives (3, 6, 7, and 9) displayed marked anti-inflammatory properties in vitro by strongly inhibiting PGE₂ biosynthesis, with IC₅₀ values in the nanomolar range. The hit compounds also efficiently interfered with leukotriene biosynthesis in cell-based systems and modulated IL-6 and PGE₂ biosynthesis in a lipopolysaccharide-stimulated J774A.1 macrophage cell line. The most promising compound 3 showed prominent in vivo anti-inflammatory activity in a mouse model, with efficacy comparable to that of dexamethasone, attenuating zymosan-induced leukocyte migration in mouse peritoneum with considerable modulation of the levels of typical pro-/anti-inflammatory cytokines.

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.

Potential Nitrogen-Based Heterocyclic Compounds for Treating Infectious Diseases: A Literature Review

Heterocyclic compounds are considered as one of the major and most diverse family of organic compounds. Nowadays, the demand for these compounds is increasing day-by-day due to their enormous synthetic and biological applications. These heterocyclic compounds have unique antibacterial activity against various Gram-positive and Gram-negative bacterial strains. This review covers the antibacterial activity of different heterocyclic compounds with nitrogen moiety. Some of the derivatives of these compounds show excellent antibacterial activity, while others show reasonable activity against bacterial strains. This review paper aims to bring and discuss the detailed information on the antibacterial activity of various nitrogen-based heterocyclic compounds. It will be helpful for the future evolution of diseases to synthesize new and effective drug molecules.

4-Methyl-7-((2-((5-methyl-1,3,4-thiadiazol-2-yl)thio)ethyl)thio)-coumarin

The novel compound 4-methyl-7-((2-((5-methyl-1,3,4-thiadiazol-2-yl)thio)ethyl)thio)-coumarin is obtained in good yield via a two-step protocol; that is, initial synthesis of the reagent 2-((2-chloroethyl)thio)-5-methyl-1,3,4-thiadiazole followed by alkylation of 7-mercapto-4-methylcoumarin. The product’s structure is assigned by 1D and 2D NMR experiments and is confirmed by single-crystal XRD.

Synthesis and characterization of new 1,3,4-thiadiazole derivatives: study of their antibacterial activity and CT-DNA binding

1,3,4-Thiadiazole molecules (1-4) were synthesized by the reaction of phenylthiosemicarbazide and methoxy cinnamic acid molecules in the presence of phosphorus oxychloride, and characterized with UV, FT-IR, ¹³C-NMR, and ¹H-NMR methods. DFT calculations (b3lyp/6-311++G(d,p)) were performed to investigate the structures' geometry and physiochemical properties. Their antibacterial activity was screened for various bacteria strains such as Enterobacter aerogenes, Escherichia coli ATCC 13048, Salmonella kentucky, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus and Gram positive such as Staphylococcus aureus ATCC 25923, Listeria monocytogenes ATCC 7644, Enterococcus faecium, Enterococcus durans, Staphylococcus aureus ATCC, Serratia marcescens, Staphylococcus hominis, Staphylococcus epidermidis, alfa Streptococcus haemolyticus, Enterococcus faecium and found to have an inhibitory effect on Klebsiella pneumoniae and Staphylococcus hominis, while molecules 1, 3 and 4 had an inhibitory effect on Staphylococcus epidermidis and alpha Streptococcus haemolyticus. The experimental results were supported by the docking study using the Kinase ThiM from Klebsiella pneumoniae. All the investigated compounds showed an inhibitory effect for the Staphylococcus epidermidis protein. In addition, the mechanism of the 1-4 molecule interaction with calf thymus-DNA (CT-DNA) was investigated by UV-vis spectroscopic methods.

Synthesis and biological evaluation of new 1,3,4-thiadiazole derivatives as potent antimicrobial agents

A series of 1,3,4-thiadiazole derivatives were designed and synthesized using N-(4-nitrophenyl)acetohydrazonoyl bromide and 1-[3,5-dimethyl-1-(4-nitrophenyl)-1H-pyrazol-4-yl]ethan-1-one as starting materials. The treatment of 1-[3,5-dimethyl-1-(4-nitrophenyl)-1H-pyrazol-4-yl]ethan-1-one with methyl hydrazinecarbodithioate or hydrazinecarbothioamide afforded 2-[1-[5-methyl-1-(4-nitrophenyl)-1H-pyrazol-4-yl]ethylidene]hydrazine derivatives. The targeted 1,3,4-thiadiazolyl derivatives were prepared by the reaction of 2-[1-[5-methyl-1-(4-nitrophenyl)-1H-pyrazol-4-yl]ethylidene]hydrazine derivatives with hydrazonoyl chloride derivatives. The reaction of N-(4-nitrophenyl)acetohydrazonoyl bromide with 2-[(methylthio)carbonthioyl]hydrazones in absolute ethanol in the presence of triethylamine afforded the corresponding 1,3,4-thiadiazole derivatives. The newly synthesized compounds were fully characterized by 1H NMR, 13C NMR, IR, MS, and elemental analysis. Moreover, the antimicrobial activity of the synthesized 1,3,4-thiadiazole derivatives were tested against E. coli, B. mycoides, and C. albicans. Four compounds outperformed the other produced compounds in terms of antimicrobial activity.

Graphical abstract

Design, Spectroscopy, and Assessment of Cholinesterase Inhibition and Antimicrobial Activities of Novel Coumarin–Thiadiazole Hybrids

A novel series of coumarin–thiadiazole hybrids, derived from substituted coumarin-3-carboxylic acids was isolated and fully characterized with the use of a number of spectroscopic techniques and XRD crystallography. Several of the novel compounds showed intensive fluorescence in the visible region, comparable to that of known coumarin-based fluorescence standards. Moreover, the new compounds were tested as potential antineurodegenerative agents via their ability to act as acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitors. Compared to the commercial standards, only a few compounds demonstrated moderate AChE and BuChE activities. Moreover, the novel derivatives were tested for their antimicrobial activity against a panel of pathogenic bacterial and fungal species. Their lack of activity and toxicity across a broad range of biochemical assays, together with the exceptional emission of some hybrid molecules, highlights the possible use of a number of the novel hybrids as potential fluorescence standards or fluorescence imaging agents.

Novel Thiadiazole-Based Molecules as Promising Inhibitors of Black Fungi and Pathogenic Bacteria: In Vitro Antimicrobial Evaluation and Molecular Docking Studies

Novel 1,3,4-thiadiazole derivatives were synthesized through the reaction of methyl 2-(4-hydroxy-3-methoxybenzylidene) hydrazine-1-carbodithioate and the appropriate hydrazonoyl halides in the presence of a few drops of diisopropylethylamine. The chemical structure of the newly fabricated compounds was inferred from their microanalytical and spectral data. With the increase in microbial diseases, fungi remain a devastating threat to human health because of the resistance of microorganisms to antifungal drugs. COVID-19-associated pulmonary aspergillosis (CAPA) and COVID-19-associated mucormycosis (CAM) have higher mortality rates in many populations. The present study aimed to find new antifungal agents using the disc diffusion method, and minimal inhibitory concentration (MIC) values were estimated by the microdilution assay. An in vitro experiment of six synthesized chemical compounds exhibited antifungal activity against Rhizopus oryzae; compounds with an imidazole moiety, such as the compound 7, were documented to have energetic antibacterial, antifungal properties. As a result of these findings, this research suggests that the synthesized compounds could be an excellent choice for controlling black fungus diseases. Furthermore, a molecular docking study was achieved on the synthesized compounds, of which compounds 2, 6, and 7 showed the best interactions with the selected protein targets.

Synthesis of new 2-(5-(5-nitrofuran-2-yl)-1,3,4-thiadiazol-2-ylimino)thiazolidin-4-one derivatives as anti-MRSA and anti-H. pylori agents

In this work, we have synthesized twenty five new 2-(5-(5-nitrofuran-2-yl)-1,3,4-thiadiazol-2-ylimino)thiazolidin-4-one derivatives bearing an aryl or heteroaryl methylene group on position 5 of thiazolidinone and evaluated their antimicrobial activity against Gram-positive and -negative bacteria as well as three metronidazole resistant Helicobacter pylori strains. Most of the compounds were very potent towards tested Gram-positive bacteria and showed an antibacterial efficacy substantially greater than ampicillin as the reference drug. However, no effectiveness was observed for the Gram-negative microorganisms. The compounds 9, 20 and 29 exhibited strong antimicrobial activity against Helicobacter pylori strains (inhibition zone > 30 mm) in 100 μg/disc and (inhibition zone > 20 mm) in 50 μg/disc. Taking these findings together, it seems that these potent antibacterial derivatives could be considered as promising agents for developing new anti-infectious drugs against microorganisms resistant to currently available antibiotics.

Potential Synthetic Routes and Metal-Ion Sensing Applications of 1,3,4-Oxadiazoles: An Integrative Review

Oxadiazoles, especially 1,3,4-oxadiazole scaffolds, stand among the foremost heterocyclic fragments with a broad spectrum of applications in diverse fields, including pharmacology, polymers, material science, and organic electronics, among others. In this comprehensive review, we summarize the pivotal synthetic strategies for 1,3,4-oxadiazole derivatives including dehydrogenative cyclization of 1,2-diacylhydrazines, oxidative cyclization of acylhydrazones, condensation cyclization, C-H activation of oxadiazole ring, decarboxylative cyclization and oxidative annulation along with plausible mechanisms. The set of 1,3,4-oxadiazoles selected from the literature and discussed herein epitomize the ease of synthesis as well as the possibility of linking π-conjugated groups; thereby encouraging the use of these molecules as important starting building blocks for a wide variety of fluorescent frameworks, particularly in the development of potential chemosensors. High photoluminescent quantum yield, excellent thermal and chemical stability, and the presence of potential coordination (N and O donor atoms) sites make these molecules a prominent choice for metal-ions sensors. An overview of selective metal-ion sensing, the detection limit along with the sensing mechanisms (photo-induced electron transfer, excited-state intramolecular proton transfer, and complex formation) is also included.

Biological activity of oxadiazole and thiadiazole derivatives

Abstract

The 5-membered oxadiazole and thiadiazole scaffolds are the most privileged and well-known heterocycles, being a common and essential feature of a variety of natural products and medicinal agents. These scaffolds take up the center position and are the core structural components of numerous drugs that belong to different categories. These include antimicrobial, anti-tubercular, anti-inflammatory, analgesic, antiepileptic, antiviral, and anticancer agents. In this review, we mostly talk about the isomers 1,2,4-oxadiazole and 1,3,4-thiadiazole because they have important pharmacological properties. This is partly because they are chemical and heat resistant, unlike other isomers, and they can be used as bio-isosteric replacements in drug design. We are reviewing the structural modifications of different oxadiazole and thiadiazole derivatives, more specifically, the anti-tubercular and anticancer pharmacological activities reported over the last 5 years, as we have undertaken this as a core area of research. This review article desires to do a thorough study and analysis of the recent progress made in the important biological isomers 1,2,4-oxadiazole and 1,3,4-thiadiazol. This will be a great place to start for future research.

Key points

• Five-membered heterocyclic compound chemistry and biological activity recent survey.

• Synthesis and pharmacological evolution of 1,2,4-oxadiazole and 1,3,4-thiadiazole are discussed in detail.

• The value and significance of heterocyclic compounds in the field of drug designing are highlighted.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00253-022-11969-0.

Etched-spiky Au@Ag plasmonic-superstructure monolayer films for triple amplification of surface-enhanced Raman scattering signals

Generally, a high quality surface-enhanced Raman spectroscopy (SERS) substrate often requires a highly-tailorable electromagnetic (EM) field generated at nanoparticle (NP) surfaces by the regulation of the morphologies, components and roughness of NPs. However, most recent universal approaches are restricted to single components, and integrating these key factors into one system to achieve the theoretically maximum signal amplification is still challenging. Herein, we design a triple SERS signal amplification platform by the coordination of spiky Au NPs with rich-tip nanostructures, controllable silver nanoshell, as well as tailorable surface roughness into one nano-system. As a result, the theoretical electromagnetic field of the interfacial self-assembled 2D substrate can be improved by nearly 5 orders of magnitude, and the ideal tracing capability for the model SERS molecule can be achieved at levels of 5 × 10^-11 M. Finally, diverse analytes in pesticide residues, environmental pollutants as well as medically diagnose down to 10^-11 M and can be fingerprinted by the proposed SERS nano-platform. Our integrated triple amplification platform not only provides an effective SERS sensing strategy, but also makes it possible to simultaneously achieve high sensitivity, stability as well as universality into one plasmonic-based SERS sensing system.

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

1,3,4-Thiadiazole nuclease, a 5-membered heterocyclic ring system containing two nitrogen and one sulfur atoms in addition to carbon atoms, is compound that showed promising results in the process of searching new diuretic agents. In this study, seven 5- and 2-thioate derivatives of 1, 3, 4-thiadiazoles were synthesized by substitution reaction using acetone as solvent and K₂CO₃ as a base. The compounds ware then characterized by using IR and NMR spectroscopy. The diuretic activity of the compounds was evaluated on Swiss albino mice by measuring urine volume, urinary pH, and urinary Na⁺, K⁺, and Cl^-. The result showed increase in urinary excretion of both water and electrolytes. 5-Methyl-substituted derivatives of 1, 3, 4-thiadiazoles showed significant increase in excretion of both water and electrolytes when they are compared to both negative control and 5-amino-substituted derivatives. The highest diuretic activity (0.82) was recorded for para-nitro-substituted benzene ring at 2-thioate group of 5-methyl-1, 3, 4-thiadiazole, while the least (0.56) was recorded for propanethioate group at 2^nd position and amine group at 5^th position of 1, 3, 4-thiadiazole. The finding of the present study showed that all the compounds have diuretic activity and 5-methyl derivatives of 1, 3, 4-thiadiazoles exhibited significant diuretic activity.

Chirality-influenced antibacterial activity of methylthiazole- and thiadiazole-based supramolecular biocompatible hydrogels

Chiral stereochemistry is a unique and fundamental strategy that determines the interaction of bacteria cells with chiral biomolecules and stereochemical surfaces. The interaction between bacteria and material surface (molecular chirality or supramolecular chirality) plays a significant role in modulating antibacterial performance. Herein, we developed inherent chiral antibacterial hydrogels by modifying the carboxyl groups of our previously reported supramolecular gelator (LPF-left handed phenylalanine gelator and DPF- right handed phenylalanine gelator) with 2-amino-5-methylthiazole (MTZ) and 5-amino-1,3,4-thiadiazole-2- thiol (TDZ). The new L/D-gelator molecules initiate self-assembly to form hydrogels through non-covalent interactions (Hydrogen bonding and π-π interactions) verified by FTIR and CD spectroscopy. Morphological studies of the xerogels revealed left and right-handed chiral nanofibers for the gelators' L-form and D-form, respectively. The resulting hydrogels exhibited inherent antibacterial activity against Gram-positive (Bacillus subtilis, Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa) bacteria, with TDZ hydrogels showing more significant antibacterial activity than MTZ hydrogels. Interestingly, the D-form (having right-handed nanofibers) of both hydrogels (MTZ and TDZ) exhibited higher antibacterial activities compared with the left-handed nanofibrous hydrogels (L-form) attributed to the stereoselective interaction of the chiral helical nanofiber. Moreover, the amplification of chirality moving from a molecular to a supramolecular level essentially improved the antibacterial action. Our results provide deep insight into the development of unique supramolecular chiral antimicrobial agents and hint at the potentiality of right-handed nanofibers (D-form) having enhanced antibacterial activity. STATEMENT OF SIGNIFICANCE: Chiral stereochemistry plays a significant role in many biological processes, which determines the interaction of bacteria cells with chiral biomolecules. The interaction between bacteria and material surface (molecular chirality or supramolecular chirality) plays a significant role in modulating antibacterial performance. Here, we deigned and synthesized unique inherent biocompatible supramolecular chiral hydrogel. From this study we concluded that the D-form (having right-handed nanofibers) of hydrogels exhibited higher antibacterial activities compared with the left-handed nanofibrous hydrogels (L-form) attributed to the stereoselective interaction of the chiral helical nanofiber. Additionally, this study also explored the amplification of chirality moving from a molecular to a supramolecular level essentially improved the antibacterial action.

Recent advancement in drug development of nitro(NO2 )-heterocyclic compounds as lead scaffolds for the treatment of Mycobacterium tuberculosis

Tuberculosis (TB) is an infectious disease caused predominantly by Mycobacterium tuberculosis (Mtb). It was responsible for approximately 1.4 million deaths worldwide in 2019. The lack of new drugs to treat drug-resistant strains is a principal factor for the slow rise in TB infections. Our aim is to aid the development of new TB treatments by describing improvements (last decade, 2011-2021) to nitro(NO₂ )-based compounds that have shown activity or pharmacological properties (e.g., anti-proliferative, anti-kinetoplastid) against Mtb. For all compounds, we have included final correlations of minimum inhibitory concentrations against Mtb (H₃₇ Rv).

1,3,4-Thiadiazole Scaffold: As Anti-Epileptic Agents

A wide range of biological activities is exhibited by 1,3,4-thiadiazole moiety such as antidiabetic, anticancer, anti-inflammatory, anticonvulsant, antiviral, antihypertensive, and antimicrobial. To date, drugs such as butazolamide, and acetazolamide. Several modifications have been done in the 1,3,4-thiadiazole moiety which showed good potency as anticonvulsant agents which are highly effective and have less toxicity. After in-depth literature survey in this review, we have compiled various derivatives of 1,3,4-thiadiazole scaffold as anticonvulsant agents.

Design, synthesis and antifungal mechanism of novel acetophenone derivatives containing 1, 3, 4-thiadiazole-2-thioethers

Plant pathogenic fungi could cause significant losses to agricultural productions. To discover new pesticides with novel structures and unique mechanisms of action, a series of novel acetophenone derivatives containing 1,3,4-thiadiazole-2-thioethers...

Synthesis and structure-activity relationship of L-methionine-coupled 1,3,4-thiadiazole derivatives with activity against influenza virus

In previous investigations, we identified a class of 1,3,4-thiadiazole derivatives with antiviral activity. N-{3-(Methylsulfanyl)-1-[5-(phenylamino)-1,3,4-thiadiazole-2-yl]propyl}benzamide emerged as a relevant lead compound for designing novel influenza A virus inhibitors. In the present study, we elaborated on this initial lead by performing chemical synthesis and antiviral evaluation of a series of structural analogues. During this research, thirteen novel 1,3,4-thiadiazole derivatives were synthesized by the cyclization of the corresponding thiosemicarbazides as synthetic precursors. The structures and the purities of the synthesized compounds were confirmed through chromatographic and spectral data. Four L-methionine-based 1,3,4-thiadiazole derivatives displayed activity against influenza A virus, the two best compounds being 24 carrying a 5-(4-chlorophenylamino)-1,3,4-thiadiazole moiety and 30 possessing a 5-(benzoylamino)-1,3,4-thiadiazole structure [antiviral EC₅₀ against influenza A/H3N2 virus: 4.8 and 7.4 µM, respectively]. The 1,3,4-thiadiazole derivatives were inactive against influenza B virus and a wide panel of unrelated DNA and RNA viruses. Compound 24 represents a new class of selective influenza A virus inhibitors acting during the virus entry process, as evidenced by our findings in a time-of-addition assay. Molecular descriptors and in silico prediction of ADMET properties of the active compounds were calculated. According to in silico ADMET and drug similarity studies, active compounds have been estimated to be good candidates for oral administration with no apparent toxicity considerations.