Synthesis and biological evaluation of newer analogues of 2,5-disubstituted 1,3,4-oxadiazole containing pyrazole moiety as antimicrobial agents

2,5-Bis(2,2,2-trifluoroethoxy)phenyl-tethered 1,3,4-Oxadiazoles Derivatives: Synthesis, In Silico Studies, and Biological Assessment as Potential Candidates for Anti-Cancer and Anti-Diabetic Agent

In the present work, a series of new 1-{5-[2,5-bis(2,2,2-trifluoroethoxy)phenyl]-1,3,4-oxadiazol-3-acetyl-2-aryl-2H/methyl derivatives were synthesized through a multistep reaction sequence. The compounds were synthesized by the condensation of various aldehydes and acetophenones with the laboratory-synthesized acid hydrazide, which afforded the Schiff's bases. Cyclization of the Schiff bases yielded 1,3,4-oxadiazole derivatives. By spectral analysis, the structures of the newly synthesized compounds were elucidated, and further, their anti-cancer and anti-diabetic properties were investigated. To examine the dynamic behavior of the candidates at the binding site of the protein, molecular docking experiments on the synthesized compounds were performed, followed by a molecular dynamic simulation. ADMET (chemical absorption, distribution, metabolism, excretion, and toxicity) prediction revealed that most of the synthesized compounds follow Lipinski's rule of 5. The results were further correlated with biological studies. Using a cytotoxic assay, the newly synthesized 1,3,4-Oxadiazoles were screened for their in vitro cytotoxic efficacy against the LN229 Glioblastoma cell line. From the cytotoxic assay, the compounds 5b, 5d, and 5m were taken for colony formation assay and tunnel assay have shown significant cell apoptosis by damaging the DNA of cancer cells. The in vivo studies using a genetically modified diabetic model, Drosophila melanogaster, indicated that compounds 5d and 5f have better anti-diabetic activity among the different synthesized compounds. These compounds lowered the glucose levels significantly in the tested model.

Novel 2,5-disubstituted-1,3,4-oxadiazole derivatives as MAO-B inhibitors: Synthesis, biological evaluation and molecular modeling studies

Thirty novel 2,5-disubstituted-1,3,4-oxadiazole derivatives bearing urea moiety were designed and synthesized. IR, ¹H-NMR, ¹³C-NMR and mass spectroscopic methods and elemental analysis were used to confirm the structures of the compounds. Their monoamine oxidase inhibitory activity was determined against the MAO-A and MAO-B isoforms. None of the compounds showed the potent MAO-A inhibitory activity, while the MAO-B inhibition was significantly found in the range of 62 to 98%. Among them, the compounds H8, H9 and H12 bearing chloro substituent at the fourth position of phenylurea were found to show potent monoamine oxidase B inhibitory activity with IC₅₀ values 0.039-0.066 µM. To define and evaluate the interaction mechanism between compound H8 and monoamine oxidase B, molecular docking studies have been made.

Evaluation of antioxidant activity and toxicity of sulfur- or selenium-containing 4-(arylchalcogenyl)-1H-pyrazoles

Pyrazoles represent a significant class of heterocyclic compounds that exhibit pharmacological properties. The present study aimed to investigate the antioxidant potential of pyrazol derivative compounds in brain of mice in vitro and the effect of pyrazol derivative compounds in the oxidative damage and toxicity parameters in mouse brain and plasma of mice. The compounds tested were 3,5-dimethyl-1-phenyl-4-(phenylselanyl)-1H-pyrazol (1a), 3,5-dimethyl-4-(phenylselanyl)-1H-pyrazole (2a), 4-((4-methoxyphenyl)selanyl)-3,5-dimethyl-1-phenyl-1H-pyrazole (3a), 4-((4-chlorophenyl)selanyl)-3,5-dimethyl-1-phenyl-1H-pyrazole (4a), 3,5-dimethyl-1-phenyl-4-(phenylthio)-1H-pyrazole (1b), 3,5-dimethyl-4-(phenylthio)-1H-pyrazole (2b), 4-((4-methoxyphenyl)thio)-3,5-dimethyl-1-phenyl-1H-pyrazole (3b), 4-((4-chlorophenyl)thio)-3,5-dimethyl-1-phenyl-1H-pyrazole (4b), and 3,5-dimethyl-1-phenyl-1H-pyrazole (1c). In vitro, 4-(arylcalcogenyl)-1H-pyrazoles, at low molecular range, reduced lipid peroxidation and reactive species in mouse brain homogenates. The compounds also presented ferric-reducing ability as well nitric oxide-scavenging activity. Especially compounds 1a, 1b, and 1c presented efficiency to 1,1-diphenyl-2-picryl-hydrazyl-scavenging activity. Compounds 1b and 1c presented 2,20 -azino-bis(3-ethylbenzthiazoline-6-sulfonic acid)-scavenging activity. In vivo assays demonstrated that compounds 1a, 1b, and 1c (300 mg/kg, intragastric, a single administration) did not cause alteration in the of δ-aminolevulinic acid dehydratase activity, an enzyme that exhibits high sensibility to prooxidants situations, in the brain, liver, and kidney of mice. Compound 1c reduced per se the lipid peroxidation in liver and brain of mice. Toxicological assays demonstrate that compounds 1a, 1b, and 1c did not present toxicity in the aspartate aminotransferase, alanine aminotransferase, urea, and creatinine levels in the plasma. In conclusion, the results demonstrated the antioxidant action of pyrazol derivative compounds in in vitro assays. Furthermore, the results showed low toxicity of compounds in in vivo assays.

Synthesis and in Vitro Antimicrobial Activity Screening of New 3-Acetyl-2,5-disubstituted-1,3,4-oxadiazoline Derivatives

Thirteen new 3-acetyl-2,5-disubstituted-1,3,4-oxadiazoline derivatives were synthesized from corresponding hydrazide-hydrazones of isonicotinic acid in the reaction with acetic anhydride. The obtained compounds were identified with the use of spectral methods (IR, ¹ H-NMR, ¹³ C-NMR, MS). In vitro antimicrobial activity screening of synthesized compounds against a panel of bacteria and fungi revealed interesting antibacterial and antifungal activity of tested 1,3,4-oxadiazoline derivatives, which is comparable to that of commonly used antimicrobial agents.

A Review Exploring Therapeutic Worth of 1,3,4-Oxadiazole Tailored Compounds

1,3,4-Oxadiazole, a five-membered aromatic ring can be seen in a number of synthetic molecules. The peculiar structural feature of 1,3,4-oxadiazole ring with pyridine type of nitrogen atom is beneficial for 1,3,4-oxadiazole derivatives to have effective binding with different enzymes and receptors in biological systems through numerous weak interactions, thereby eliciting an array of bioactivities. Research in the area of development of 1,3,4-oxadiazole-based derivatives has become an interesting topic for the scientists. A number of 1,3,4-oxadiazole based compounds with high therapeutic potency are being extensively used for the treatment of different ailments, contributing to enormous development value. This work provides a systematic and comprehensive review highlighting current developments of 1,3,4-oxadiazole based compounds in the entire range of medicinal chemistry such as anticancer, antifungal, antibacterial, antitubercular, anti-inflammatory, antineuropathic, antihypertensive, antihistaminic, antiparasitic, antiobesity, antiviral, and other medicinal agents. It is believed that this review will be of great help for new thoughts in the pursuit for rational designs for the development of more active and less toxic 1,3,4-oxadiazole based medicinal agents.

Efficient Synthesis and in Silico Studies of the Benzimidazole Hybrid Scaffold with the Quinolinyloxadiazole Skeleton with Potential α-Glucosidase Inhibitory, Anticoagulant, and Antiplatelet Activities for Type-II Diabetes Mellitus Management and Treating Thrombotic Disorders

The current study evaluates antidiabetic, anticoagulant, and antiplatelet activity of novel benzimidazole-containing quinolinyl oxadiazoles. These derivatives are synthesized and characterized using spectroscopy (FT-IR, ¹H NMR, and mass spectroscopy) and single-crystal X-ray diffraction methods. The inhibitory effects of these compounds were evaluated by the α-glucosidase inhibitory assay and shows the activity in the range of IC₅₀ = 0.66 ± 0.05 to 3.79 ± 0.46 μg/mL. In addition, molecular docking studies revealed that benzimidazole-containing quinolinyl oxadiazoles can correctly dock into the target receptor protein of the human intestinal α-glucosidase, while their bioavailability/drug-likeness was predicted to be acceptable but requires further optimization. On the other hand, compound 8a and 8d showed anticoagulant activity as they enhanced the clotting time from control 180-410 and 180-390 s, respectively, in platelet rich plasma and 230-460 and 230-545 s in platelet poor plasma. Furthermore, only 8a showed antiplatelet activity by inhibiting epinephrine-induced platelet aggregation, and the observed aggregation inhibition was found to be 93.4%. Compounds 8a-f show nontoxic properties because of the non-hydrolyzing properties in the RBC cells. In addition, 8a and 8d show anti-edema and anti-hemorrhagic properties in the experimental mice. These findings reveal that benzimidazole-containing quinolinyl oxadiazoles act as α-glucosidase inhibitors to develop novel therapeutics for treating type-II diabetes mellitus and can act as lead molecules in drug discovery as potential antidiabetic and antithrombotic agents.

Photophysical Properties of some 1,3,4-Oxadiazole Derivatives Containing Phenolphtalein, Fluorene and Bisphenol A Units

The photophysical properties of the three 1,3,4-oxadiazole derivatives containing fluorene (Ox-FL); fluorene and phenolphtaleine (Ox-FL-FF); or fluorene and bisphenol A (Ox-FL-BPA) moieties in the main chain were investigated by the fluorescence and absorption spectroscopy in different solvents and in the solid state. The electronic absorption spectra included a strong absorption band located in the 270-395 nm region, with a maxima around at 302 nm. The fluorescence excitation spectra were also characterized by one broad band, appearing in the wavelength range of 220-340 nm. All samples displayed the emission bands around 356-373 nm and exhibit high quantum yields ranged from 31.61 to 90.77%, in chloroform solution. The sensitivity of the emission spectra on medium characteristics (polarity, acidity and basicity) were evaluated by using the Catalan solvent scale and the fluorescence titration with a dilute acid solution.

Synthesis and Pharmacological Activities of Pyrazole Derivatives: A Review

Pyrazole and its derivatives are considered a pharmacologically important active scaffold that possesses almost all types of pharmacological activities. The presence of this nucleus in pharmacological agents of diverse therapeutic categories such as celecoxib, a potent anti-inflammatory, the antipsychotic CDPPB, the anti-obesity drug rimonabant, difenamizole, an analgesic, betazole, a H2-receptor agonist and the antidepressant agent fezolamide have proved the pharmacological potential of the pyrazole moiety. Owing to this diversity in the biological field, this nucleus has attracted the attention of many researchers to study its skeleton chemically and biologically. This review highlights the different synthesis methods and the pharmacological properties of pyrazole derivatives. Studies on the synthesis and biological activity of pyrazole derivatives developed by many scientists around the globe are reported.

Synthesis and Pharmacological Activities of Pyrazole Derivatives: A Review

Pyrazole and its derivatives are considered a pharmacologically important active scaffold that possesses almost all types of pharmacological activities. The presence of this nucleus in pharmacological agents of diverse therapeutic categories such as celecoxib, a potent anti-inflammatory, the antipsychotic CDPPB, the anti-obesity drug rimonabant, difenamizole, an analgesic, betazole, a H2-receptor agonist and the antidepressant agent fezolamide have proved the pharmacological potential of the pyrazole moiety. Owing to this diversity in the biological field, this nucleus has attracted the attention of many researchers to study its skeleton chemically and biologically. This review highlights the different synthesis methods and the pharmacological properties of pyrazole derivatives. Studies on the synthesis and biological activity of pyrazole derivatives developed by many scientists around the globe are reported.

Synthesis, characterization and biological evaluation of novel 2,5 substituted-1,3,4 oxadiazole derivatives

In the present study, a series of 3-(5-cyclohexyl-1,3,4-oxadiazol-2-yl)-N-substituted aniline have been synthesized by multistep reaction scheme. Benzohydrazide was used as the starting material. The structures of all synthesized compounds are characterized and confirmed by FT-IR, 1H and C13 NMR and mass spectral studies with the intention of developing the novel biologically active compounds. All title synthetic compounds were screened for their antidiabetic, anti-inflammatory and anticancer activities.