Condensed bridgehead nitrogen heterocyclic system: synthesis and pharmacological activities of 1,2,4-triazolo-[3,4-b]-1,3,4-thiadiazole derivatives of ibuprofen and biphenyl-4-yloxy acetic acid

Design, synthesis, and in-Silco ADME prediction of some novel bis(1,3,4-thiadiazoles) encapsulated lipid-chitosan nano capsule decorative with magnetic nanoparticles and their potential anti-helicobacter pylori activity

Helicobacter pylori (H. pylori) is an extremely prevalent human pathogen globally that leads to severe illnesses. Sadly, the worldwide issue of H. pylori's resistance to antimicrobial medications persists. In this context, creating an anti-H. pylori vaccine that can deliver a satisfactory eradication rate with fewer side effects would be highly beneficial. In this regard, a new series of bis(1,3,4-thiadiazoles) was synthesized and assessed for antimicrobial activity against H. pylori. Combining two bioactive 1,3,4-thiadiazole portions within a single molecule to create a new bis-heterocycle represents an efficient strategy to produce powerful compounds and address issues of resistance and effectiveness. Every synthesized compound showed outstanding inhibition results. Compounds 5c and 8 exhibited the lowest MIC values, recorded at 7.5 and 15.6 μg/mL, respectively. Theoretical predictions were employed to evaluate ADME, leading to outcomes of low solubility, stability, and bioavailability. The effective agents aimed at H. pylori were encapsulated in an appropriate newly developed nanocarrier to tackle challenges related to low bioavailability and stability. Further tests were carried out to evaluate the efficacy of antimicrobials against H. pylori, resulting in promising results. Additionally, the MIC values decreased by 4 and 2 times relative to their original synthetic versions. The activity of the enzyme urease was assessed before nanoencapsulation, showing an IC50 value of 8.99 μg/mL, which was reduced to 7.8 μg/mL after nanoencapsulation.

Anticancer dinuclear Ir(III) complex activates Nrf2 and interferes with NAD(H) in cancer cells

Dinuclear complex [Ir2(μ-L1)(η5-Cp*)2Cl2](PF6)2 (1) exhibits low micromolar cytotoxic activity in vitro in various human cancer cells (GI50 = 1.7-3.0 μM) and outperformed its mononuclear analogue [Ir(η5-Cp*)Cl(L2)]PF6 (2; GI50 > 40.0 μM); Cp* = pentamethylcyclopentadienyl, L1 = 4-chloro-2,6-bis[5-(pyridin-2-yl)-1,3,4-thiadiazol-2-yl]pyridine, L2 = 5-(pyridin-2-yl)-1,3,4-thiadiazol-2-amine. Compound 1 upregulated the Keap1/Nrf2 oxidative stress-protective pathway in the treated MV4-11 acute myeloid leukemia cells. In connection with the redox-mediated mode of action of 1, its NADH-oxidizing activity was detected in solution (1H NMR), while NAD+ remained intact (with formate as a hydride source). Surprisingly, only negligible NADH oxidation was detected in the presence of the reduced glutathione and ascorbate. Following the results of in-solution experiments, NAD(H) concentration was assessed in 1-treated MV4-11 cancer cells. Besides the intracellular NADH oxidation in the presence of 1, the induced oxidative stress also led to a decrease of NAD+, resulting in depletion of both NAD+/NADH coenzymes. The discussed findings provide new insight into the biochemical effects of catalytic anticancer compounds that induce cell death via a redox-mediated mode of action.

Synthesis and biological evaluation of novel aminoguanidine derivatives as potential antibacterial agents

In an effort to identify novel antibacterial agents, we presented two series of aminoguanidine derivatives that were designed by incorporating 1,2,4-triazol moieties. All compounds exhibited strong in vitro antibacterial activity against a variety of testing strains. Compound 5f was identified as a potent antibacterial agent with a minimum inhibitory concentration (MIC) of 2-8 µg/mL against S. aureus, E. coli, S. epidermidis, B. subtilis, C. albicans, multi-drug resistant Staphylococcus aureus and multi-drug resistant Escherichia coli and low toxicity (Hela > 100 µM). Membrane permeability and transmission electron microscopy (TEM) image studies demonstrated that compound 5f permeabilized bacterial membranes, resulting in irregular cell morphology and the rapid death of bacteria. The results of the present study suggested that aminoguanidine derivatives with 1,2,4-triazol moieties were the intriguing scaffolds for the development of bactericidal agents.

Pharmacological investigations of newly synthesized oxazolones and imidazolones as COX-2 inhibitors

Oxazoles and Imidazoles are heterocyclic compounds with significant biological activities. The present study explores the pharmacological effects of some new oxazole and imidazole derivatives as potential COX-2 inhibitors. Docking studies of the compounds against targeted proteins COX-2 and TACE manifested good binding affinities for both the targets supporting their anti-inflammatory potential. Compounds (3F-A, 3F-B, N-A, N-B) were evaluated for in vivo anti-inflammatory effects by carrageenan-induced paw edema. Among all, compound N-A was found to be the most effective as it displayed most pronounced reduction in inflammation that was comparable to indomethacin. The in vivo tissue antioxidant activity was performed for estimation of the level of catalase, GSH, GST, and thiobarbituric acid in paw tissue. The results exhibited that targeted compounds improved the oxidative stress and restored the expression of enzymes. H &E staining revealed that aforesaid compounds displayed well-defined restoration of cellular damage. Compound NA exhibited maximum structural and functional preservation. Reduction in the expression of inflammatory markers was also analyzed by ELISA and maximum reduction in protein expression (COX-2 and TNF-a) was observed for compound N-B. Quantification of mRNA was done using PCR and a decrease in the expression of COX-2 mRNA level in treatment groups was depicted by all the new compounds but N-B showed maximum reduction in enzyme expression. All the results obtained from the present study have shown the significant anti-inflammatory potential of new compounds via the COX-2 inhibition pathway.

Can nonsteroidal anti-inflammatory drugs (NSAIDs) be repurposed for fungal infection?

Nonsteroidal anti-inflammatory drugs (NSAIDs) are an important class of anti-inflammatory drugs widely used for the treatment of musculoskeletal disorders, mild-to-moderate pain, and fever. This review aimed to explain the functional role and possible mechanisms of the antifungal effects of NSAIDs alone or in combination with antifungal drugs in vitro and in vivo. Several studies reported that NSAIDs such as aspirin, ibuprofen, diclofenac, indomethacin, ketorolac, celecoxib, flurbiprofen, and nimesulide had antifungal activities in vitro, either fungistatic or fungicidal, against different strains of Candida, Aspergillus, Cryptococcus, Microsporum, and Trichophyton species. These drugs inhibited biofilm adhesion and development, and yeast-to-hypha conversion which may be related to a prostaglandin E2 (PGE2)/PGEx-dependent mechanism. Modulating PGE2 levels by NSAIDs during fungal infection can be introduced as a possible mechanism to overcome. In addition, some important mechanisms of the antifungal activities of NSAIDs and their new derivatives on fungi and host immune responses are summarized. Overall, we believe that using NSAIDs along with classical antifungal drugs has the potential to be investigated as a novel therapeutic strategy in clinical studies. Furthermore, combination therapy can help manage resistant strains, increase the efficacy of antifungal drugs, and reduce toxicity.

Impact of the central atom and halido ligand on the structure, antiproliferative activity and selectivity of half-sandwich Ru(II) and Ir(III) complexes with a 1,3,4-thiadiazole-based ligand

Half-sandwich complexes [Ru(η6-pcym)(L1)X]PF6 (1, 3) and [Ir(η5-Cp*)(L1)X]PF6 (2, 4) featuring a thiadiazole-based ligand L1 (2-(furan-2-yl)-5-(pyridin-2-yl)-1,3,4-thiadiazole) were synthesized and characterized by varied analytical methods, including single-crystal X-ray diffraction (X = Cl or I, pcym = p-cymene, Cp* = pentamethylcyclopentadienyl). The structures of the molecules were analysed and interpreted using computational methods such as Density Functional Theory (DFT) and Quantum Theory of Atoms in Molecules (QT-AIM). A 1H NMR spectroscopy study showed that complexes 1-3 exhibited hydrolytic stability while 4 underwent partial iodido/chlorido ligand exchange in phosphate-buffered saline. Moreover, 1-4 demonstrated the ability to oxidize NADH (reduced nicotinamide adenine dinucleotide) to NAD+ with Ir(III) complexes 2 and 4 displaying higher catalytic activity compared to their Ru(II) analogues. None of the complexes interacted with reduced glutathione (GSH). Additionally, 1-4 exhibited greater lipophilicity than cisplatin. In vitro biological analyses were performed in healthy cell lines (CCD-18Co colon and CCD-1072Sk foreskin fibroblasts) as well as in cisplatin-sensitive (A2780) and -resistant (A2780cis) ovarian cancer cell lines. The results indicated that Ir(III) complexes 2 and 4 had no effect on human fibroblasts, demonstrating their selectivity. In contrast, complexes 1 and 4 exhibited moderate inhibitory effects on the metabolic and proliferation activities of the cancer cells tested (selectivity index SI > 3.4 for 4 and 2.6 for cisplatin; SI = IC50(A2780)/IC50(CCD-18Co)), including the cisplatin-resistant cancer cell line. Based on these findings, it is possible to emphasize that mainly complex 4 could represent a further step in the development of selective and highly effective anticancer agents, particularly against resistant tumour types.

New Semisynthetic Penicillins Obtained by Coupling of the 6-Aminopenicillanic Acid with 5-Mercapto-1,2,4-triazoles-3,4-disubstituted

In a basic medium, 5-Mercapto-1,2,4-triazoles pass into the thiol form, allowing their transformation into sodium salts, which, in reaction with sodium monochloroacetate, lead to sodium 5-thioacetates of 1,2,4-triazoles-3,4-disubstituted. Sulfur derivatives converted to pivalic mixed anhydrides were used as active forms in the acylation of 6-amino penicillanic acid (6-AP) to obtain new semisynthetic penicillins. They contain in the molecule, together with the β-lactam ring, the nucleus 3-[(5-nitroindazol-1'-yl-methyl)]-4-aryl-5-mercapto-1,2,4-triazole, both contributing to an important antibacterial effect. The structure of the new antibiotics was confirmed by the results of elemental and spectral analysis (FT-IR, ¹H- and ¹³C-NMR). The synthetic penicillins were tested for toxicological action and antibacterial activity and the obtained results were close to those for amoxicillin, the reference drug.

Synthesis, crystal structure investigation and computational approach to discover potential hydrazide derivatives as a potent inhibitor of cyclooxygenase-2 enzyme

This study reports the synthesis of two new hydrazide derivatives, namely, (E)-N'-(4- bromobenzylidene)-2-(4-isobutylphenyl)propanehydrazide (4a) and (E)-N'-benzylidene-2-(4-isobutylphenyl)propanehydrazide (4b), respectively. The compounds were synthesized by the reaction of benzaldehyde with Ibuprofen acid hydrazide. Their structures were confirmed by X-ray crystallography. To try to do a more detailed investigation, computational studies including Hirshfeld surface analyses, energy frameworks, density functional theory (DFT) optimizations, frontier orbital analyses, molecular electrostatic potential analyses, and natural bond orbital analyses of the studied compounds are performed. Moreover, molecular docking and dynamics simulations of complexes of the compounds with the cyclooxygenase-2 (COX-2) enzyme were performed to determine the anti-inflammatory potential of the compounds. These analyses predicted the compounds to show maximum chemical interactions and be dynamically stable during simulation time. Furthermore, estimation of binding free energies confirmed the high binding affinity of the compounds for the COX-2 enzyme.

Theoretical investigation of some 1,2,4-triazole-based molecules synthetized

In this study, theoretical calculations were made and interpreted to obtain chemical, nonlinear optical properties and antibacterial activity parameters of 14 registered heterocyclic 4, 5-dihydro-1H-1, 2, 4-triazole-5-one derivatives in the literature. For this purpose, first of all, 14 compounds registered in the literature and two main structures were optimized to find the minimum energy and the most stable structure by using the “B3LYP/6-311++G (d, p)” methods. HOMO–LUMO energies calculated from these optimized structures, energy differences and chemical parameters derived from HOMO–LUMO energies (I; Ionization potential, A; electron affinity, ΔE; Energy Gap, χ; electronegative σ; molecular softness, ω; Electrophilic Index, ε; Nucleophilic Index, μ; Chemical Potential) values were determined. In addition to chemical parameters, polar calculations were made for nonlinear optical properties, and it was evaluated whether the compounds could be optical materials. Finally, the antimicrobial properties of the molecules were calculated theoretically and compared with the experimental results by calculating the volume.

Exploring ibuprofen derivatives as α-glucosidase and lipoxygenase inhibitors: Cytotoxicity and in silico studies

This study reports the synthesis of a series of ibuprofen derivatives, including thiosemicarbazides 4a-f, 1,3,4-oxadiazoles 5a-f, 1,3,4-thiadiazoles 6a-f, 1,2,4-triazoles 7a-f, and their S-alkylated derivatives 8a-d. All of the newly synthesized derivatives were analyzed using ¹ H NMR, ¹³ C NMR spectroscopy, and high-resolution mass spectra (electron ionization) spectrometry. These synthetic molecules were examined for their in vitro baking yeast α-glucosidase and soybean 15-lipoxygenase (15-LOX) inhibition and cell viability studies. The results revealed that the compounds N-(3,4-dichlorophenyl)-5-[1-(4-isobutylphenyl)ethyl]-1,3,4-oxadiazol-2-amine 5f (IC₅₀ 3.05 ± 1.23 µM) and N-(3-fluorophenyl)-5-[1-(4-isobutylphenyl)ethyl]-1,3,4-oxadiazol-2-amine 5b (IC₅₀ 3.12 ± 1.21 µM) were the most potent with respect to the α-glucosidase enzyme while in case of 15-LOX, the compound 4-(2,4-dichlorophenyl)-1-[2-(4-isobutylphenyl)propanoyl]thiosemicarbazide 4e showed potent inhibition with an IC₅₀ value of 55.41 ± 0.41 µM. All these compounds were found least toxic by displaying a blood mononuclear cell viability value of 69.2%-97.8% by the MTT assay compared to the standards when assayed at 0.25 mM concentration. Molecular docking analyses were conducted to evaluate the inhibition profiles of these derivatives against the said enzymes and the data supported the in vitro profiles.

One-Pot Synthesis of Some New s-Triazole Derivatives and Their Potential Application for Water Decontamination

A rapid, efficient, and one-pot protocol has been developed for the synthesis of cyclized 2,6-dimethyl-5-substituted-thiazolo[3,2-b]-s-triazoles (3a-c) through the interaction of 5-methyl-1H-s-triazole-3-thiol (1) with aliphatic ketones (2a-d) in refluxing acetic acid in the presence of a catalytic amount of sulfuric acid (AcOH/H+) while with aromatic ketones (5a-d), a mixture of uncyclized 3-methyl-s-triazolylthioacetophenone derivatives (6a-d) and cyclized 6-aryl-2-methyl-thiazolo[3,2-b]-s-triazoles (7a-d) has been produced. With this catalytic system, inexpensive sulfuric acid was utilized as a catalyst, which prevented the production of poisonous and irritating halo carbonyl compounds. On the other hand, the interaction of s-triazole 1 with cyano compounds (9a,b) afforded the corresponding 6-amino-2-methyl-5-substituted-thiazolo[3,2-b]-s-triazoles (10a,b). Similarly, treatment of 4-amino-3-methyl-s-triazole-5-thiol (12) with aliphatic and aromatic ketones (2c and 5a-e) afforded directly 3-methyl-7H-s-triazolo[3,4-b]-1,3,4-thiadiazines (13a and 14a-e). Further, reaction of 12 with cyano compounds (9a,b) under the same reaction conditions yielded the corresponding 3-methyl-s-triazolo[3,4-b]-1,3,4-thiadiazole derivatives (15a,b). The reaction mechanism was studied, and the structures of all novel compounds were verified using spectroscopy and elemental analysis. Moreover, the potential application of the synthesized compounds toward heavy metal ions and inorganic anion removal from aqueous solution has been investigated. The removal effectiveness for metal ions reached up to 76.29%, while for inorganic anions it reached up to 100%, indicating that such synthesized compounds are promising adsorbents for water remediation.

Design and Synthesis of Novel Ibuprofen Derivatives as Selective COX-2 inhibitors and potential anti-inflammatory agents: Evaluation of PGE2, TNF-α, IL-6 and histopathological study

BACKGROUND

The reported binding mode of ibuprofen in the COX-2 binding site indicated that the carboxylic group binds with Arg-120 and Tyr-355 at the entrance of the cyclooxygenase channel and does not extend into the pocket. This accounted for the non-selectivity of ibuprofen. Based on this fact, we assumed that extending the length of the carboxylic acid moiety in ibuprofen and adding more bulky rigid groups as well as bulky groups carrying H-bonding functions might increase the selectivity and reduce the side effects of ibuprofen while maintaining its analgesic and anti-inflammatory activities.

OBJECTIVE

In this work, four series of ibuprofen derivatives were designed and prepared. The compounds were designed by increasing the length of the carboxylate group along with the incorporation of large hydrophobic groups.

METHOD

Four series of ibuprofen derivatives were synthesized starting from ibuprofen. Their chemical structure was confirmed by spectral data. All the compounds were tested for their COX inhibitory activity.

RESULTS

The best COX-2 activity and selectivity were obtained with compounds 5c and 5d, which were subjected to further in vivo testing (carrageenan-induced paw edema, rat serum PGE2, TNF- α and IL-6, hot plate latency test) to investigate their anti-inflammatory and analgesic activities as well as their effects on the gastric mucosa. The anti-inflammatory activity of both compounds was comparable to that of ibuprofen, diclofenac, and indomethacin. Both compounds suppressed the production of PGE2 as well as the rat serum concentrations of both TNF-α and IL-6. This potent anti-inflammatory and analgesic behavior was not accompanied by any effect on the gastric mucosa. Docking simulation studies of the two compounds explained the higher selectivity for the COX-2 enzyme.

CONCLUSION

Potent and selective ibuprofen derivatives can be successively obtained by extending the length of the carboxylic acid moiety in ibuprofen and adding more bulky rigid groups as well as bulky groups with H-bonding functions.

Design, Synthesis, and Biological Evaluation of Novel Triazolothiadiazoles Derived From NSAIDs as Anticancer Agents

BACKGROUND

Although transplantation, surgical resection, and tumor ablation are treatment options available following early diagnosis of HCC, their efficacy is restricted due to poor prognosis and high recurrence rates. Hence, small molecules with high selectivity and bioactivity are urgently required.

OBJECTIVE

This study presents the synthesis of a series of new triazolothiadiazole derivatives (1a-3j) with NSAID moieties and their cytotoxic bioactivities.

METHODS

The new synthetic derivatives (1-3; 1a-3j) and NSAIDs ibuprofen, naproxen, and flurbiprofen that commonly used in clinics were screened against human liver (Huh7), breast (MCF7), and colon (HCT116) carcinoma cell lines under in vitro conditions via NCI-sulforhodamine B assay.

RESULTS

The 4-methoxyphenyl substituted condensed derivatives 1h, 2h, and 3h were the most active compounds. Based on its high potency, compound 3h was selected for the further biological evaluation of hepatocellular carcinoma cell lines, and the mechanisms underlying cell death induced by 3h were determined. The results revealed that compound 3h induced apoptosis and cell cycle arrest in the sub G1 phase in human liver cancer cells.

CONCLUSION

These new small molecules may be used for the development of new lead compounds.

Immobilization and Release Studies of Triazole Derivatives from Grafted Copolymer Based on Gellan-Carrying Betaine Units

New polymer-bioactive compound systems were obtained by immobilization of triazole derivatives onto grafted copolymers and grafted copolymers carrying betaine units based on gellan and N-vinylimidazole. For preparation of bioactive compound, two new types of heterocyclic thio-derivatives with different substituents were combined in a single molecule to increase the selectivity of the biological action. The 5-aryl-amino-1,3,4 thiadiazole and 5-mercapto-1,2,4-triazole derivatives, each containing 2-mercapto-benzoxazole nucleus, were prepared by an intramolecular cyclization of thiosemicarbazides-1,4 disubstituted in acidic and basic medium. The structures of the new bioactive compounds were confirmed by elemental and spectral analysis (FT-IR and 1H-NMR). The antimicrobial activity of 1,3,4 thiadiazoles and 1,2,4 triazoles was tested on gram-positive and gram-negative bacteria. The triazole compound was chosen to be immobilized onto polymeric particles by adsorption. The Langmuir, Freundlich, and Dubinin-Radushkevich adsorption isotherm were used to describe the adsorption equilibrium. Also, the pseudo-first and pseudo-second models were used to elucidate the adsorption mechanism of triazole onto grafted copolymer based on N-vinylimidazole and gellan (PG copolymer) and grafted copolymers carrying betaine units (PGB1 copolymer). In vitro release studies have shown that the release mechanism of triazole from PG and PGB1 copolymers is characteristic of an anomalous transport mechanism.

Novel (+)-Neoisopulegol-Based O-Benzyl Derivatives as Antimicrobial Agents

Discovery of novel antibacterial agents with new structures, which combat pathogens is an urgent task. In this study, a new library of (+)-neoisopulegol-based O-benzyl derivatives of aminodiols and aminotriols was designed and synthesized, and their antimicrobial activity against different bacterial and fungal strains were evaluated. The results showed that this new series of synthetic O-benzyl compounds exhibit potent antimicrobial activity. Di-O-benzyl derivatives showed high activity against Gram-positive bacteria and fungi, but moderate activity against Gram-negative bacteria. Therefore, these compounds may serve a good basis for antibacterial and antifungal drug discovery. Structure-activity relationships were also studied from the aspects of stereochemistry of the O-benzyl group on cyclohexane ring and the substituent effects on the ring system.

Anticancer Activity of Triazolo-Thiadiazole Derivatives and Inhibition of AKT1 and AKT2 Activation

The fusion of 1,2,4-triazole and 1,3,4-thiadiazole rings results in a class of heterocycles compounds with an extensive range of pharmacological properties. A series of 1,2,4-triazolo[3,4-b]-1,2,4-thiadiazoles was synthesized and tested for its enzyme inhibition potential and anticancer activity. The results show that 1,2,4-triazolo[3,4-b]-1,2,4-thiadiazoles display potent anticancer properties in vitro against a panel of cancer cells and in vivo efficacy in HT-29 human colon tumor xenograft in CB17 severe combined immunodeficient (SCID) mice. Preliminary mechanistic studies revealed that KA25 and KA39 exhibit time- and concentration-dependent inhibition of Akt Ser-473 phosphorylation. Molecular modeling experiments indicated that 1,2,4-triazolo[3,4-b]-1,2,4-thiadiazoles bind well to the ATP binding site in Akt1 and Akt2. The low acute toxicity combined with in vitro and in vivo anticancer activity render triazolo[3,4-b]thiadiazoles KA25, KA26, and KA39 promising cancer therapeutic agents.

THE SEARCH FOR NEUROPROTECTIVE COMPOUNDS AMONG NEW ETHYLTHIADIAZOLE DERIVATIVES

The aim of the study is to search compounds with neuroprotective properties among new ethylthiadiazole derivatives in simulated traumatic brain injury.

Materials and methods. The experiment was carried out on 78 white male rats 270±20 g line “Wistar” 5–6 months of age and 120 outbred sexually mature mice weighing 20±2 grams. The article describes the search for compounds with neuroprotective properties among new ethylthiadiazole derivatives under the codes LKHT 4–15, LKHT 10–18, LKHT 11–18, and LKHT 12–18 in experimental traumatic brain injury in rats. Acute toxicity of the compounds was studied. Pharmacological screening was performed using behavioral and neurological research methods. The McGraw stroke score scale modified by I.V. Gannushkina and the mNSS psychometric scale were used in the study. The open field and Rota-rod tests were used to assess the behavioral status of the animals.

Results. The compound-LKHT 12–18 at a dose of 50 mg/kg was detected as a leader. In pharmacological correction of pathology, this compound had the lowest percentage of fatality among the studied compounds (8%), the severity of neurological deficit was significantly reduced, the lowest scores and a higher level of motor activity of the limbs were registered. The number of rearing in the group of animals receiving the compound LKHT 12–18 at the dose of 50 mg/kg increased by 1.5 times, statistically significant (p<0.05) in comparison with the control group. Based on the results of the “Rota-rod” test, the total time of holding animals on the rod for 3 attempts was statistically significantly different in the groups administered with LKHT 12–18 derivatives (1.5 times longer) at the dose of 50 mg/kg compared with the control (p<0.05).

Conclusion. Based on the results obtained in this study, it is planned to study in more detail the compound LKHT 12–18 at the dose of 50 mg/kg.

Hassan A, Makhlouf MM, Bräse S. Chemistry and Biological Activities of 1,2,4-Triazolethiones-Antiviral and Anti-Infective Drugs

Mercapto-substituted 1,2,4-triazoles are very interesting compounds as they play an important role in chemopreventive and chemotherapeutic effects on cancer. In recent decades, literature has been enriched with sulfur- and nitrogen-containing heterocycles which are used as a basic nucleus of different heterocyclic compounds with various biological applications in medicine and also occupy a huge part of natural products. Therefore, we shed, herein, more light on the synthesis of this interesting class and its application as a biologically active moiety. They might also be suitable as antiviral and anti-infective drugs.

Two decades of the synthesis of mono- and bis-aminomercapto[1,2,4]triazoles

4-Amino-5-mercapto[1,2,4]triazole and its 3-substituted derivatives have proven to be of biological interest and provide access to a new class of biologically active heterocyclic compounds for biomedical applications. This study will be helpful for scientific researchers interested in the chemistry of bifunctional versatile compounds as it provides a collection of all the methods for the preparation of 3-substituted-4-amino-5-mercapto[1,2,4]triazoles with aliphatic, aromatic, and heterocyclic moieties during the period from 2000 to mid-2020.

New aryl Schiff bases of thiadiazole derivative of ibuprofen as DNA binders and potential anticancer drug candidates

The work presented in this paper describes the synthesis of two new aryl Schiff bases [(E)-N-(4-(benzyloxy)-3-methoxybenzylidene)-5-(1-(4-isobutylphenyl)ethyl)-1,3,4-thiadiazol-2-amine] (ASB-1) and [(E)-N-(4-(benzyloxy)benzylidene)-5-(1-(4-isobutylphenyl)ethyl)-1,3,4-thiadiazol-2-amine] (ASB-2). These compounds were characterized by different analytical techniques and then studied for DNA binding. Binding studies were carried out at neutral pH (7.0) and at 37 °C by theoretical and experimental methods including DFT, molecular docking, spectroscopy (UV-visible, fluorescence), cyclic voltammetry (CV) and viscometry. Further investigations of these compounds were done on hepatocellular carcinoma; Huh-7 cancer cell line. Binding constant, free energy change and binding site size, i.e. K_b, ΔG and n were evaluated which indicated that both ASB-1 and ASB-2 bind significantly and spontaneously with the DNA. However, data revealed relatively greater binding of ASB-1 with DNA. Spectral and voltammetric results were found supportive of each other. Binding site sizes and viscosity measurements verified the mixed binding mode of interactions as observed in molecular docking analysis, i.e. intercalation with groove binding. DNA binding studies were very well correlated with the in-vitro studies performed on Huh-7 cell line as well as normal HEK-293 cell lines. The compound ASB-1 not only showed greater binding affinity toward DNA but also showed greater anticancer potency with least IC₅₀ value as compared to ASB-2.

Synthesis of Schiff and Mannich bases of news-triazole derivatives and their potential applications for removal of heavy metals from aqueous solution and as antimicrobial agents

An efficient synthesis of Schiff and Mannich bases of news-triazole derivatives under mild conditions has been developed for the removal of Pb²⁺, Cd²⁺, Ca²⁺, and Mg²⁺from aqueous solutions and as antimicrobial agents.

Alpha-glucosidase and amylase inhibitory effects of Eruca vesicaria subsp. longirostris essential oils: synthesis of new 1,2,4-triazole-thiol derivatives and 1,3,4-thiadiazole with potential inhibitory activity

Context: The substantial increase in the number of diabetics has encouraged the search for new pharmacological strategies to face this problem. In this regard, triazole and its derivatives have attracted considerable attention for the past few decades due to their pharmacological significance. Objective: Evaluation of the inhibitory activity of α-glucosidase and α-amylase in essential oils extracted from plant Eruca vesicaria (L) Cav. subsp. longirostris (Brassicaceae) (EVL) and to verify whether the triazoles and thiadiazol bearing the lipophilic 4-methylthiobutyl group synthesized from the essential oil contribute to this activity. Materials and methods: The essential oils were extracted by hydrodistillation from leaf, stem, root, and fruit of EVL, and their chemical compositions were analyzed by gas chromatography and gas chromatography-mass spectrometry. We present here the synthesis of three new types of 1,2,4-triazole-thiol and 1,3,4-thiadiazol and the structures were confirmed by NMR, mass spectrometry. The α-glucosidase and α-amylase inhibitory activities were investigated in vitro. Results: The main compound in fruit, stem, and root was erucin (96.6, 85.3, and 83.7%, respectively). The three essential oils of the fruit, stem, and root have strong inhibitory activity on α-glucosidase and α-amylase; IC₅₀ values of roots were 0.81 ± 0.02 μg/mL and 0.13 ± 0.01 μg/mL, respectively. Derivatives 1 b, 2 b, 3 b, and 2c showed remarkable inhibitory activity against α-glucosidase with potencies better than that of acarbose with IC₅₀ values ranging between 0.49 and 1.43 μM. Conclusions: Current results indicate that ECL fruit essential oil can be used as a natural precursor for the synthesis of triazoles as potential hypoglycemic agents.

Design, synthesis and biological evaluation of benzoxazolinone-containing 1,3,4-thiadiazoles as TNF-α inhibitors

A library of nineteen benzoxazolinone-based 1,3,4-thiadiazoles has been synthesized and screened for their anti-inflammatory activity. The compound 1f exhibited a potent anti-inflammatory activity with an inhibition of 65.83% and 32.50% after 3 h and 5 h respectively. It also exhibited a significant in vitro (p < 0.01), TNF- α inhibitory activity with 51.44 % inhibition. The compound 1f showed hydrogen bonding with GLN 61 and interactions with TYR 119, TYR 151 and GLY 121. The histopathology report showed that none of the compounds caused gastric ulceration. The results from the in vivo & in vitro antiinflammatory activity along with In Silico studies exhibit that benzoxazolinone-based 1,3,4-thiadiazoles may be used in the future development of anti-inflammatory drugs.

Synthesis, Characterization and Anticonvulsant Activity of Novel Fused 1,2,4-Triazolo-1,3,4-Thiadiazoles

A novel category of 1,2,4-triazolo-1,3,4-thiadiazoles were ready by the utilization of 3-amino-4-hydroxybenzoate as the beginning material. Spectral information results were used for the establishing of prepared compounds. Compounds were screened anticonvulsant activity for obtaining better results by MES test and scPTZ methods. The rotarod method was used for neurotoxicity analysis. Majority of the compounds displayed distinguished anticonvulsant impact practically identical to standard drugs (phenytoin and carbamazepine) with slight neurotoxicity.

Design and synthesis of 2,6-di(substituted phenyl)thiazolo[3,2-b]-1,2,4-triazoles as α-glucosidase and α-amylase inhibitors, co-relative Pharmacokinetics and 3D QSAR and risk analysis

Ten fused heterocyclic derivatives bearing the 2,6-di(subsituted phenyl)thiazolo[3,2-b]-1,2,4-triazoles as central rings were synthesized and structures of the compounds were established by analytical and spectral data using FTIR, EI-MS, ¹H NMR and ¹³C NMR techniques. In vitro inhibitory activities of synthesized compounds on α-amylase, α-glucosidase and α-burylcholinesterase (α-BuChE) were evaluated using a purified enzyme assays. Compound 5c demonstrated strong and selective α-amylase inhibitory activity (IC₅₀=1.1μmol/g). 5g exhibited excellent inhibition against α-glucosidase (IC₅₀=1.2μmol/g) when compared with acarbose (IC₅₀=4.7μmol/g) as a positive reference. Compound 5i was found to be most potent derivative against α-BuChE with the IC₅₀ of 1.5μmol/g which was comparable to the value obtained for (4.7μmol/g) positive control (i.e. galantamine hydrobromide). Molecular dockings of synthesized compounds into the binding sites of human pancreatic α-amylase, intestinal maltase-glucoamylase and neuronal α-butrylcholinesterase allowed to shed light on the affinity and binding mode of these novel inhibitors. Preliminary structure-activity relationship (SAR) studies were carried out to understand the relationship between molecular structural features and inhibition activities of synthesized derivatives. These data suggested that compounds 5c, 5g and 5i are promising candidates for hitto- lead follow-up in the drug-discovery process for the treatment of Alzheimer's disease and hyperinsulinamia.

Synthesis, characterization and pharmacological evaluation of pyrazolyl urea derivatives as potential anti-inflammatory agents

p38α mitogen activated protein kinase (MAPK) inhibitors provide a novel approach for the treatment of inflammatory disorders. A series of fifteen pyrazolyl urea derivatives (3a—o) were synthesized and evaluated for their p38α MAPK inhibition and antioxidant potential. Compounds 3a—e, 3g and 3h showed low micromolar range potency (IC₅₀ values ranging from 0.037 ± 1.56 to 0.069 ± 0.07 µmol/L) compared to the standard inhibitor SB 203580 (IC₅₀ = 0.043 ± 3.62 µmol/L) when evaluated for p38α MAPK inhibition by an immunosorbent-based assay. Antioxidant activity was measured by a 2,2′-diphenyl-1-picryl hydrazyl radical (DPPH) free radical scavenging method and one of the compounds, 3c, showed better percentage antioxidant activity (75.06%) compared to butylated hydroxy anisole (71.53%) at 1 mmol/L concentration. Compounds 3a—e, 3g and 3h showed promising in vivo anti-inflammatory activity (ranging from 62.25% to 80.93%) in comparison to diclofenac sodium (81.62%). The ulcerogenic liability and lipid peroxidation activity of these compounds were observed to be less in comparison to diclofenac sodium. These compounds also potently inhibited the lipopolysaccharide (LPS)-induced TNF-α release in mice (ID₅₀ of 3a—c = 19.98, 11.32 and 9.67 mg/kg, respectively). Among the screened compounds, derivative 3c was found to be the most potent and its binding mode within the p38α MAPK is also reported.

In Vitro Interactions between Non-Steroidal Anti-Inflammatory Drugs and Antifungal Agents against Planktonic and Biofilm Forms of Trichosporon asahii

Increasing drug resistance has brought enormous challenges to the management of Trichosporon spp. infections. The in vitro antifungal activities of non-steroidal anti-inflammatory drugs (NSAIDs) against Candida spp. and Cryptococcus spp. were recently discovered. In the present study, the in vitro interactions between three NSAIDs (aspirin, ibuprofen and diclofenac sodium) and commonly used antifungal agents (fluconazole, itraconazole, voriconazole, caspofungin and amphotericin B) against planktonic and biofilm cells of T. asahii were evaluated using the checkerboard microdilution method. The spectrophotometric method and the XTT reduction assay were used to generate data on biofilm cells. The fractional inhibitory concentration index (FICI) and the ΔE model were compared to interpret drug interactions. Using the FICI, the highest percentages of synergistic effects against planktonic cells (86.67%) and biofilm cells (73.33%) were found for amphotericin B/ibuprofen, and caspofungin/ibuprofen showed appreciable percentages (73.33% for planktonic form and 60.00% for biofilm) as well. We did not observe antagonism. The ΔE model gave consistent results with FICI (86.67%). Our findings suggest that amphotericin B/ibuprofen and caspofungin/ibuprofen combinations have potential effects against T. asahii. Further in vivo and animal studies to investigate associated mechanisms need to be conducted.