Synthesis of 3-((2,4-dichlorophenoxy)methyl)-1,2,4-triazolo(thiadiazoles and thiadiazines) as anti-inflammatory and molluscicidal agents

Molluscicidal and Schistosomicidal Activities of 2-(1H-Pyrazol-1-yl)-1,3,4-thiadiazole Derivatives

Background/objectives: Schistosomiasis is caused by flatworms of the genus Schistosoma, for which mollusks of the genus Biomphalaria are intermediate hosts. Niclosamide (NCL) is a molluscicide recommended by the World Health Organization (WHO) for control of Biomphalaria. Although effective, it is expensive and environmentally toxic, which raises concerns regarding its widespread use. As a result, we explored new synthetic substances as alternative strategies for controlling Biomphalaria glabrata. We evaluated the molluscicidal activity of 2-(1H-py-razol-1-yl)-1,3,4-thiadiazole and 2-(4,5-dihydro-1H-pyrazol-1-yl)-1,3,4-thiadiazole derivatives against B. glabrata snails and embryos, as well as Schistosoma cercariae (infective larvae). Methods: Adult and young snails were added to 24-well plates containing 20 synthetic compounds from the PDAN series for initial screening over 96 h at a concentration of 100 ppm. Water and NCL (2 ppm) were used as the negative and positive controls, respectively. Active compounds in the adult B. glabrata assay were selected for the tests vs. embryos and cercariae. Results: In the initial screen, only PDAN 52 (63 ± 4%) and 79 (12 ± 3%) showed molluscicidal activity at a concentration of 100 ppm up to 48 h. Consequently, we selected only PDAN 52. The LC50 value found in the tests on embryos after 24 h of treatment was 20 ± 2 ppm and, after 48 h, it was 4 ± 0.5 ppm. Against cercariae, we measured an LC50 value of 68 ± 5 ppm after 4 h of treatment. PDAN 52 did not induce marked toxicity against a second mollusk, Physella acuta, after 48 h of exposure. Conclusions: We highlight the promising molluscicidal activity of PDAN 52 against different developmental stages of the mollusk, B. glabrata, as well the infective larvae of Schistosoma mansoni.

Urease inhibitory potential of pyridine-containing triazolothiadiazole and triazolothiadiazine scaffolds for the treatment of ulceration and kidney stone: in vitro screening, kinetics mechanism, and in silico computational analysis

The hyperactivity of urease enzyme leads to various complications including gastritis and peptic ulcer. A diverse variety of natural and synthetic inhibitors have shown a tremendous potential to inhibit the urease enzyme, thus decreasing the hyperactivity and reducing the risk for the development of urinary calculi and other similar problems. Therefore, we herein report a family of fused heterocycles such as triazolothiadiazoles (4a-h, 5a-f) and triazolothiadiazines (6a-h) as potential antiurease agents with IC50 values in the range 10.41-41.20 µM. Several compounds were identified as potential lead candidates. Among them, compounds 4e and 4f from triazolothiadiazole series showed the highest inhibitory potential with IC50 values of 11.62 ± 0.34 and 10.35 ± 0.14 µM), respectively, whereas 6e from triazolothiadiazine series emerged as the most potent inhibitor with an IC50 value of 10.41 ± 0.13 µM. These compounds exhibited two-fold strong inhibitory efficacy against urease as compared to standard inhibitor, thiourea (IC50 = 22.48 ± 0.67 µM). The mechanistic insights from kinetics experiments for compounds 4e, 4f, and 6e revealed the competitive mode of inhibition with Ki values of 8.65 ± 0.004, 7.04 ± 0.012, and 8.31 ± 0.007 µM, respectively. The in vitro results were further explored through in silico computational docking analysis which reflects that binding of ligands with Ni ions and His492 play a crucial role in urease inhibition. In silico predicted physicochemical properties and ADME profile reflect drug-like nature of these molecules.Communicated by Ramaswamy H. Sarma.

Chemistry and Biological Activity of Thieno[3,4-b]quinoline, Thieno[3,4-c] quinolone, Thieno[3,2-g]quinoline and Thieno[2,3-g]quinoline Derivatives: A Review (Part IX)

Abstract:

Over the previous decades, thieno-quinoline derivatives have acquired great interest due to their synthetic and biological applications. These reports have been disclosed on Thienoquinoline synthesis such as thieno[3,4-b]quinoline; thieno[3,4-c]quinolone; thieno [3,2-g]quinoline; thieno[2,3- g] quinoline; spiro-thieno[2,3-g]quinoline; benzo[b]thiophen-iso- quinoline derivatives, and therefore in the existent review, we provided an inclusive update on the synthesis of thienoquinolines. Characterization of the preparation methods and reactivity is categorized based on their types of reactions as addition, alkylation, chlorination, acylation, oxidation, reduction, cyclization and cyclo-condensation. Hence, this study will help the researchers to obtain knowledge from the last literature research to conquer their resolve problems in designing new compounds and processes.

Caffeine and Purine Derivatives: A Comprehensive Review on the Chemistry, Biosynthetic Pathways, Synthesis-Related Reactions, Biomedical Prospectives and Clinical Applications

Caffeine and purine derivatives represent interesting chemical moieties, which show various biological activities. Caffeine is an alkaloid that belongs to the family of methylxanthine alkaloids and it is present in food, beverages, and drugs. Coffee, tea, and some other beverages are a major source of caffeine in the human diet. Caffeine can be extracted from tea or coffee using hot water with dichloromethane or chloroform and the leftover is known as decaffeinated coffee or tea. Caffeine and its derivatives were synthesized via different procedures on small and large scales. It competitively antagonizes the adenosine receptors (ARs), which are G protein-coupled receptors largely distributed in the human body, including the heart, vessels, brain, and kidneys. Recently, many reports showed the effect of caffeine derivatives in the treatment of many diseases such as Alzheimer's, asthma, parkinsonism, and cancer. Also, it is used as an antioxidant, anti-inflammatory, analgesic, and hypocholesterolemic agent. The present review article discusses the synthesis, reactivity, and biological and pharmacological properties of caffeine and its derivatives. The biosynthesis and biotransformation of caffeine in coffee and tea leaves and the human body were summarized in the review.

Synthesis and Reactions of Thieno[2,3-c]quinolines from Arylaldehyde and Arylamine Derivatives: A Review (Part VIII)

Abstract:

In this review article, many thieno[2,3-c]quinoline derivatives are shown from many aspects, including different preparation and processing methods, by the use of recent systems and high technology. This review includes many chemical reactions that show the preparation of thieno[2,3- c]quinoline derivatives from aryl-aldehyde, arylamine derivatives, and other chemical reagents. Several synthesized thieno[2,3-c]quinoline derivatives are described in this review article, including: benzothieno[ 2,3-c]quinoline; 1,2,4-triazolo[4,3-a]quinoline; benzothieno [2,3-c]tetrazolo[1,5-a]quinoline; acetyl-amino-benzothieno[2,3-c]quinolinones; methoxythieno[3',2': 4,5]thieno[2,3-c]quinoline; amino- thieno-thieno[2,3-c]quinoline-methaniminium chloride; thieno [3',2':4,5]thieno[2,3-c]quinolineimidazole; thieno[2,3-c]phenanthroline; naphtho[1,2-f]thieno [3',2':4,5]thieno[2,3- c][1,2,4]triazolo[4,3-a]quinoline; naphtho-tetrazolo[1,5-a]thieno[3',2':4,5] thieno[2,3-c]quinoline; and benzo[4,5]thieno[2,3-c]quinoline-2-carbonitrile.

Exploration of antiproliferative potential of modified triazole-benzohydrazone scaffold: Multitarget approach

A novel series of triazole-benzohydrazone hybrids was efficiently designed and synthesized as antiproliferative agents, targeting different kinases. All compounds were screened via the National Cancer Institute (NCI) against 60 cancer cell lines, where compounds 16, 17, and 18 exhibited growth inhibition percent (GI%) of various leukemia subpanels with values of 70.33%, 64.13%, and 76.03%, respectively. Compound 18 showed broad-spectrum antiproliferative efficacy toward most cancer cells, with outstanding potency regarding melanoma (MALME-3M GI% = 101.82%) and breast cancer cell lines (MCF7 GI% = 85.87%), while proving safe toward the WI-38 normal cell line, compared to doxorubicin. Multikinase investigation including vascular endothelial growth factor receptor 2 (VEGFR-2), mesenchymal epithelial transition factor (c-Met), proto-oncogene B-Raf, mitogen-activated protein kinase kinase, extracellular signal-regulated kinase, and phosphoinositide 3-kinase was accomplished to reveal its plausible mechanism of action, giving the ultimate potency against both VEGFR-2 and c-Met with IC50 values of 0.055 and 0.042 μM, respectively, while displaying moderate to good inhibition concerning the remaining kinases. DNA binding capability was excluded using the methyl green colorimetric assay. Further, it exhibited both early and late apoptotic induction by about 16- and 9.4-fold over the control, respectively, triggering cell cycle arrest in the G2/M phase. Physicochemical properties and bioavailability radar plot inferred drug-likeness characteristics for compound 18. The molecular docking study assessed the binding pattern with the active sites of c-Met and VEGFR-2.

Synthesis of tetrazoles through a domino reaction: A molecular electron density theory study of energetics, selectivities, and molecular mechanistic aspects

This study corresponds to a molecular electron density theory (MEDT) investigation to shed light on the energetics, selectivities, and molecular mechanistic aspects of an experimental domino reaction. Theoretical evidences at the M06-2X/6-31G(d) level indicates that this domino reaction includes three different successive steps and is initialized by a stepwise HCl elimination from precursor chlorohydrazone NPCH to yield nitrile imine NI-2. A subsequent stepwise and highly regioselective [3 + 2] cycloaddition (32CA) reaction of NI-2 toward tetramethylguanidine TMG-3 affords corresponding formal [3 + 2] cycloadduct CA-1 as the sole product. Finally, a stepwise HNMe2 elimination experienced by CA-1 leads to amino triazole ATA as an aromatic five-membered target product. Computed rate constants reveal that the HCl elimination step should be considered as the bottleneck of this domino reaction. However, a topological analysis of electron localization function (ELF) of NI-2 demonstrates a zwitterionic type (zw-type) 32 C A reaction is expected between NI-2 and TMG-3. This 32CA reaction also displays an almost noticeable polar character arising from moderate electrophilicity and strong nucleophilicity of NI-2 and TMG-3, respectively. The regioselectivity of 32CA reaction can be explained via analysis of Parr functions values calculated at the reactive sites of reagents. The molecular mechanism of the 32CA reaction was explored through portraying bond forming/breaking patterns involved in this polar, stepwise, and zw-type reaction by means of the ELF analysis. Indeed, formation of both C-N single bonds along the first and second steps takes place through coupling of the corresponding pseudoradical centers.

Synthesis, design, and antimicrobial activity of pyrido[2,3‐d][1,2,4]triazolo[4,3‐a]pyrimidinones based on quinoline derivatives

The pyrido[2,3‐d]pyrimidine moieties are one of the most biologically widespread heterocyclic compounds as antimicrobial, antioxidant, antitubercular, antiviral and anti‐inflammatory. Hence, we synthesized an efficient new series of 2‐thioxo‐pyrido[2,3‐d]pyrimidinone, 2‐hydrazinyl‐(quinolin‐2‐yl)pyrido[2,3‐d]pyrimidinone,N′‐(quinolin‐2‐yl)‐pyrido[2,3‐d]pyrimidine‐(formo/aceto)‐hydrazide and substituted‐(quinolin‐2‐yl)pyrido[2,3‐d][1,2,4]triazolo[4,3‐a]pyrimidinone derivatives. The characterization of new compounds was corresponded by using spectroscopic techniques, IR, NMR and Mass spectra. In vitro, all compounds were evaluated as antimicrobial activity compared with cefotaxime sodium and nystatin as the standard drug. This work deals with the exploration of the new heterocyclic compounds and medicinal diversity of quinoline‐pyrido[2,3‐d][1,2,4]triazolo[4,3‐a]pyrimidine derivatives that might pave the way for long in the discovery of therapeutic medicine for future drug design.

Vision on Synthetic and Medicinal Facets of 1,2,4-Triazolo[3,4-b][1,3,4]thiadiazine Scaffold

The present review article strives to compile the latest synthetic approaches for the synthesis of triazolothiadiazine and its derivatives, along with their diverse pharmacological activities, viz. anticancer, antimicrobial, analgesic and anti-inflammatory, antioxidant, antiviral, enzyme inhibitors (carbonic anhydrase inhibitors, cholinesterase inhibitors, alkaline phosphatase inhibitors, anti-lipase activity, and aromatase inhibitors) and antitubercular agents. The review focuses particularly on the structure–activity relationship of biologically important 1,2,4-triazolo[3,4-b][1,3,4]thiadiazines, which have profound importance in drug design, discovery and development. In silico pharmacokinetic and molecular modeling studies have also been summarized. It is hoped that this review article will be of help to researchers engaged in the development of new biologically active entities for the rational design and development of new target-oriented 1,2,4-triazolo[3,4-b][1,3,4]thiadiazine-based drugs for the treatment of multifunctional diseases.

Molluscicides against the snail-intermediate host of Schistosoma: a review

Schistosomiasis, a neglected tropical disease (NTD), is one of the most prevalent parasitoses in the World. Certain freshwater snail species are the intermediate host in the life cycle of schistosome species. Controlling snails employing molluscicides is an effective, quick, and convenient intervention strategy to prevent the spread of Schistosoma species in endemic regions. Advances have been made in developing both synthetic molluscicides and molluscicides derived from plants. However, at present, the development of molluscicides is not adapted to the actual demand for snails and schistosoma controlling. We undertake a systematic review of exploitation and application of synthetic molluscicides and molluscicides derived from plants to combat intermediate host snails. The detailed molluscicidal activity, structure–activity relationship, structural feature, and possible mechanism of some molluscicides are also highlighted, which may afford an important reference for the design of new, more effective molluscicides with low environmental impact and realize the aim of controlling schistosome at transmission stages.

Synthesis, 3D-QSAR, and Molecular Modeling Studies of Triazole Bearing Compounds as a Promising Scaffold for Cyclooxygenase-2 Inhibition

Targeting of cyclooxygenase-2 (COX-2) has emerged as a powerful tool for therapeutic intervention because the overexpression of this enzyme is synonymous with inflammation, cancer, and neurodegenerative diseases. Herein, a new series of 1,2,4-triazole Schiff bases scaffold with aryl and heteroaryl systems 9a–12d were designed, synthesized, structurally elucidated, and biologically evaluated as a potent COX-2 blocker. The rationale beyond the current study is to increase the molecule bulkiness allowing a selective binding to the unique hydrophobic pocket of COX-2. Among the triazole–thiazole hybrids, the one with the para-methoxy moiety linked to a phenyl ring 12d showed the highest In vitro selectivity by COX-2 inhibition assay (IC₅₀ of 0.04 μM) and in situ anti-inflammatory activity when evaluated using the protein denaturation assay (IC₅₀ of 0.88 μM) in comparison with commercially available selective COX-2 inhibitor, Celecoxib (IC₅₀ of 0.05 μM). Towards the COX-2 selectivity, ligand-based three dimensional quantitative structures activity relationship (3D-QSAR) employing atomic-based and field-based approaches were performed and resulted in the necessity of triazole and thiazole/oxazole scaffolds for COX-2 blocking. Furthermore, the molecular modeling study indicated a high selectivity and promising affinity of our prepared compounds to COX-2, especially the hydrophobic pocket and the mouth of the active site holding hydrogen-bonding, hydrophobic, and electrostatic interactions. In Silico absorption, delivery, metabolism, and excretion (ADME) predictions showed that all the pharmacokinetic and physicochemical features are within the appropriate range for human use.

An insight on medicinal attributes of 1,2,4-triazoles

The present review aims to summarize the pharmacological profile of 1,2,4-triazole, one of the emerging privileged scaffold, as antifungal, antibacterial, anticancer, anticonvulsant, antituberculosis, antiviral, antiparasitic, analgesic and anti-inflammatory agents, etc. along with structure-activity relationship. The comprehensive compilation of work carried out in the last decade on 1,2,4-triazole nucleus will provide inevitable scope for researchers for the advancement of novel potential drug candidates having better efficacy and selectivity.

Novel 1,2,4-triazole derivatives as apoptotic inducers targeting p53: Synthesis and antiproliferative activity

A series of novel thiazolo[3,2-b][1,2,4]-triazoles 3a-n has been synthesized and evaluated in vitro as potential antiproliferative. Compounds 3b-d exhibited significant antiproliferative activity. Compound 3b was the most potent with Mean GI₅₀ 1.37 µM comparing to doxorubicin (GI₅₀ 1.13 µM). The transcription effects of 3b, 3c and 3d on the p53 were assessed and compared with the reference doxorubicin. The results revealed an increase of 15-27 in p53 level compared to the test cells and that p53 protein level of 3b, 3c and 3d was significantly inductive (1419, 571 and 787 pg/mL, respectively) in relation to doxorubicin (1263 pg/mL). The docking study of the new compounds 3a-n revealed high binding scores for the new compounds toward p53 binding domain in MDM2. The docking analyses revealed the highest affinities for compounds 3b-d which induced p53 activity in MCF-7 cancer cells. Compound 3b which exhibited the highest antiproliferative activity and induced the highest increase in p53 level in MCF-7 cells showed also the highest affinity to MDM2.

The different modes of chiral [1,2,3]triazolo[5,1-b][1,3,4]thiadiazines: crystal packing, conformation investigation and cellular activity

The crystal structures of four new chiral [1,2,3]triazolo[5,1-b][1,3,4]thiadiazines are described, namely, ethyl 5'-benzoyl-5'H,7'H-spiro[cyclohexane-1,6'-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine]-3'-carboxylate, C₁₉H₂₂N₄O₃S, ethyl 5'-(4-methoxybenzoyl)-5'H,7'H-spiro[cyclohexane-1,6'-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine]-3'-carboxylate, C₂₀H₂₄N₄O₄S, ethyl 6,6-dimethyl-5-(4-methylbenzoyl)-6,7-dihydro-5H-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine-3-carboxylate, C₁₇H₂₀N₄O₃S, and ethyl 5-benzoyl-6-(4-methoxyphenyl)-6,7-dihydro-5H-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine-3-carboxylate, C₂₁H₂₀N₄O₄S. The crystallographic data and cell activities of these four compounds and of the structures of three previously reported similar compounds, namely, ethyl 5'-(4-methylbenzoyl)-5'H,7'H-spiro[cyclopentane-1,6'-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine]-3'-carboxylate, C₁₉H₂₂N₄O₃S, ethyl 5'-(4-methoxybenzoyl)-5'H,7'H-spiro[cyclopentane-1,6'-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine]-3'-carboxylate, C₁₉H₂₂N₄O₄S, and ethyl 6-methyl-5-(4-methylbenzoyl)-6-phenyl-6,7-dihydro-5H-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine-3-carboxylate, C₂₂H₂₂N₄O₃S, are contrasted and compared. For both crystallization and an MTT assay, racemic mixtures of the corresponding [1,2,3]triazolo[5,1-b][1,3,4]thiadiazines were used. The main manner of molecular packing in these compounds is the organization of either enantiomeric pairs or dimers. In both cases, the formation of two three-centre hydrogen bonds can be detected resulting from intramolecular N-H...O and intermolecular N-H...O or N-H...N interactions. Molecules of different enantiomeric forms can also form chains through N-H...O hydrogen bonds or form layers between which only weak hydrophobic contacts exist. Unlike other [1,2,3]triazolo[5,1-b][1,3,4]thiadiazines, ethyl 5'-benzoyl-5'H,7'H-spiro[cyclohexane-1,6'-[1,2,3]triazolo[5,1-b][1,3,4]thiadiazine]-3'-carboxylate contains molecules of only the (R)-enantiomer; moreover, the N-H group does not participate in any significant intermolecular interactions. Molecular mechanics methods (force field OPLS3e) and the DFT B3LYP/6-31G+(d,p) method show that the compound forming enantiomeric pairs via weak N-H...N hydrogen bonds is subject to greater distortion of the geometry under the influence of the intermolecular interactions in the crystal. For intramolecular N-H...O and S...O interactions, an analysis of the noncovalent interactions (NCIs) was carried out. The cellular activities of the compounds were tested by evaluating their antiproliferative effect against two normal human cell lines and two cancer cell lines in terms of half-maximum inhibitory concentration (IC₅₀). Some derivatives have been found to be very effective in inhibiting the growth of Hela cells at nanomolar and submicromolar concentrations with minimal cytotoxicity in relation to normal cells.

Design, Synthesis, and Biological Evaluation of 1,2,4-Thiadiazole-1,2,4-Triazole Derivatives Bearing Amide Functionality as Anticancer Agents

A novel library of amide functionality having 1,2,4-thiadiazole-1,2,4-triazole (8a–j) analogs was designed, synthesized, and structures were characterized by ¹H NMR, ¹³C NMR, and mass (ESI–MS) spectral data. Further, all compounds were evaluated for their anticancer activities against four different cancer cell lines including breast cancer (MCF-7, MDA MB-231), lung cancer (A549), and prostate cancer (DU-145) by MTT reduction assay method, and etoposide acts as a standard drug. The results confirmed that majority of the synthesized compounds showed moderate to potent anticancer activities aligned with four cell lines. Among the synthesized compounds, 8b, 8c, 8d, 8e, 8g and 8i displayed more potent activity along with inhibitory concentration values ranging from 0.10 ± 0.084 to 11.5 ± 6.49 µM than the standard IC₅₀ values, which ranges from 1.91 ± 0.84 to 3.08 ± 0.135 µM, respectively.

Molecular docking studies, biological evaluation and synthesis of novel 3-mercapto-1,2,4-triazole derivatives

Synthesis of bioactive heterocyclic compounds having effective biological activity is an essential research area for wide-ranging applications. In this study, a conventional methodology has been developed for the synthesis of a series of new 3-mercapto-1,2,4-triazole derivatives 4a-f. The purity and structure of the synthesized molecules were confirmed by ¹H NMR, ¹³C NMR and elemental analysis. In addition, the prepared compounds were screened for their anti-proliferative activity against three human cancer cell lines including A549 (lung cancer), MCF7 (breast cancer) and SKOV3 (ovarian cancer) using MTT reduction assay. All the tested compounds demonstrated remarkable cytotoxic activity with IC₅₀ values ranging from 3.02 to 15.37 µM. The heterocyclic compound bearing 3,4,5-trimethoxy moiety was found to be the most effective among the series displaying an IC₅₀ of 3.02 µM specifically against the ovarian carcinoma cancer cell line (SKOV3). Moreover, Annexin V-FITC/propidium iodide staining assay indicated that this compound can induce apoptosis in SKOV3 cells. Furthermore, cell cycle assay showed a significant cell cycle arrest at the G2/M phase in a dose-dependent manner for this compound. The molecular docking results was showed binding modes of potent compound 4d perfectly corroborated the suggestion of binding to the colchicine site. The entire results conclude that 3-mercapto-1,2,4-triazole derivatives can be synthesized by a green method for biological and pharmacological applications. New analogs of 3-mercapto-1,2,4-triazole potential derivatives for anti-proliferative activity were synthesized. Cytotoxic activity of all synthesized compounds was evaluated against tree human cancer cell lines: lung (A549), breast (MCF7) and ovarian (SKOV3).

Synthesis of Novel Benzodifuranyl; 1,3,5-Triazines; 1,3,5-Oxadiazepines; and Thiazolopyrimidines Derived from Visnaginone and Khellinone as Anti-Inflammatory and Analgesic Agents

Novel (4-methoxy or 4,8-dimethoxy)-3-methyl-N-(6-oxo-2-thioxo-1,2,3, 6-tetrahydro- pyrimidin-4-yl) benzo [1,2-b: 5, 4-b'] difuran-2-carboxamide (5a-b) has been synthesized by the reaction of visnagenone-ethylacetate (2a) or khellinone-ethylacetate (2b) with 6-aminothiouracil in dimethylformamide or refluxing of benzofuran-oxy-N-(2-thioxopyrimidine) acetamide (4a-b) in sodium ethoxide to give the same products (5a,b) in good yields. Thus, compounds 5a-b are used as an initiative to prepare many new heterocyclic compounds such as 2-(4-(3-methylbenzodifuran- 2-carbox-amido) pyrimidine) acetic acid (6a-b), N-(thiazolo[3, 2-a]pyrimidine)-3-methylbenzo- difuran-2-carboxamide (7a-b), N-(2-thioxopyrimidine)-methylbenzodifuran-2-carbimidoylchloride (8a-b), N-(2-(methyl-thio) pyrimidine)-3-methylbenzodifuran-2-carbimidoylchloride (9a-b), N-(2, 6 -di(piperazine or morpholine)pyrimidine)-1-(3-methylbenzodifuran)-1-(piperazine or morpholine) methanimine(10a-d), 8-(methylbenzodifuran)-thiazolopyrimido[1,6-a][1,3,5]triazine-3,5-dione (11a -b), 8-(3-methyl benzodifuran)-thiazolopyrimido[6,1-d][1,3,5]oxadiazepine-trione (12a-b), and 2,10 -di(sub-benzylidene)-8-(3-methylbenzodifuran)-thiazolopyrimido[6,1-d][1,3,5]oxadiazepine-3,5,11- trione (13a-f). All new chemical structures were illustrated on the basis of elemental and spectral analysis (IR, NMR, and MS). The new compounds were screened as cyclooxygenase-1/ cyclooxygenase-2 (COX-1/COX-2) inhibitors and had analgesic and anti-inflammatory activities. The compounds 10a-d and 13a-f had the highest inhibitory activity on COX-2 selectivity, with indices of 99-90, analgesic activity of 51-42% protection, and anti-inflammatory activity of 68%-59%. The inhibition of edema for the same compounds, 10a-d and 13a-f, was compared with sodium diclofenac as a standard drug.

Synthesis, Anti-inflammatory, Antimicrobial Potential and Molecular Docking Studies of 4,5-Disubstituted-1,2,4-Triazole Thioacetate Derivatives

Background:

In the present study synthesis and biological assessment of nine new ethyl [(4,5-disubstituted- 4H-1,2,4-triazol-3-yl)sulfanyl]acetate derivatives 2(a-i) is performed.

Methods:

The title compounds were characterized by their analytical and spectral data. All the synthesized compounds were screened for their in vivo anti-inflammatory activity using carrageenaninduced rat paw oedema method and in vitro antimicrobial activity. All the compounds exhibited good anti-inflammatory activity; especially compound 2h produced the maximum effect i.e., 62.5 % comparable to that of standard, diclofenac. The antimicrobial screening results indicated that some of the newly synthesized compounds showed good antibacterial activity, especially against Escherichia coli.

Results:

All the synthesized thioacetate derivatives of triazoles were also studied for their interactions with the enzymes COX-I and COX-II, two important targets of inflammation pathway, through docking analysis. All the compounds showed good binding affinities with both the enzymes with a maximum value of -8.1 for 2e kcal/mol against COX-I.

Conclusion:

Docking analysis predicted that our compounds reduce inflammation nonselectively by inhibiting both COX-I and COX-II of inflammatory pathway just like other nonselactive NSAIDS.

Cytotoxic, DNA Cleavage and Pharmacokinetic Parameter Study of Substituted Novel Furan C-2 Quinoline Coupled 1, 2, 4-Triazole and Its Analogs

BACKGROUND

Furan, quinoline and triazoles are known for their wide spectrum biologically active molecules. A series of novel furan C-2 quinoline and 1, 2, 4-triazole (FQT) coupled hybrids were designed and synthesized to evaluate for their DNA cleavage and cytotoxic studies.

OBJECTIVES

In this work we describe the synthesis and biological evaluation of furan C-2 quinoline coupled triazoles exposed for cytotoxic and DNA cleavage study.

METHODS

The electrophoretic DNA cleavage studies on λ-DNA (Eco-RI/Hinda-III double digest) using agarose gelelectrophoresis and the cytotoxic activity were carried out by MTT assay method.

RESULTS

The results revealed that, the molecules 7(a-o) did cleave the DNA completely with no trace of fragments at 100 µg concentration, on the other hand, cytotoxic assay was achieved by two different human cancer cell lines (melanoma cell line-A375 and breast cancer cell line MDA-MB 231). Among the synthesized compounds 7a, 7b, 7c and 7k exhibited potent cytotoxic activity with IC50 values ranging from 2.9, 4.0, 7.8 and 5.1 µg/ml against A375 and 6.2, 9.5, 11.3 and 7.3 µg/ml against, MDA-MB 231, respectively.

CONCLUSION

In synthesized compounds 7(a-o) exhibited complete DNA cleavage at 100 µg/ml and the compounds 7a, 7b, 7c and 7k showed very less cytotoxic in nature. The structure activity relationship revealed that, the presence of halogen group/atoms at para position of phenyl ring remarkably enhanced the DNA cleavage and cytotoxic activities among the synthesized compounds.

Synthesis and characterisation of new 3-methyl-6-[1-(pyrimidin-4-yl)ethyl]-5H-pyrimido[5,4-e][1,2,4]triazolo[3,4-b][1,3,4]thiadiazine derivatives

A new series of 3-methyl-6-[1-(pyrimidin-4-yl)ethyl]-5 H-pyrimido[5,4- e][1,2,4]triazolo[3,4- b][1,3,4]thiadiazine derivatives was synthesised through the condensation reaction of 5-bromo-4-[1-(5-bromo-2,6-dichloropyrimidin-4-yl)ethyl]-2-chloro-6-methylpyrimidine and 4-amino-5-methyl-4 H-1,2,4-triazole-3-thiol.

Antileishmanial potential of fused 5-(pyrazin-2-yl)-4H-1,2,4-triazole-3-thiols: Synthesis, biological evaluations and computational studies

A series of newer 1,2,4-triazole-3-thiol derivatives 5(a-m) and 6(a-i) containing a triazole fused with pyrazine moiety of pharmacological significance have been synthesized. All the synthesized compounds were screened for their in vitro antileishmanial and antioxidant activities. Compounds 5f (IC₅₀=79.0µM) and 6f (IC₅₀=79.0µM) were shown significant antileishmanial activity when compared with standard sodium stibogluconate (IC₅₀=490.0µM). Compounds 5b (IC₅₀=13.96µM) and 6b (IC₅₀=13.96µM) showed significant antioxidant activity. After performing molecular docking study and analyzing overall binding modes it was found that the synthesized compounds had potential to inhibit L. donovani pteridine reductase 1 enzyme. In silico ADME and metabolic site prediction studies were also held out to set an effective lead candidate for the future antileishmanial and antibacterial drug discovery initiatives.

Pharmacologic Evaluation of Antidepressant Activity and Synthesis of 2-Morpholino-5-phenyl-6H-1,3,4-thiadiazine Hydrobromide

Substituted thiadiazines exert a reliable therapeutic effect in treating stress, and a schematic description of their ability to influence all aspects of a stress response has been depicted. This study was conducted to pharmacologically evaluate compound L-17, a substituted thiadiazine, (2-morpholino-5-phenyl-6H-1,3,4-thiadiazine, hydrobromide) for possible anti-psychotic/antidepressant activity. Compound L-17 was synthesized by cyclocondensation of α-bromoacetophenone with the original morpholine-4-carbothionic acid hydrazide. Pharmacologic evaluations were conducted using methods described by E.F. Lavretskaya (1985), and in accordance with published guidelines for studying drugs for neuroleptic activity. Compound L-17 was evaluated for various possible mechanisms of action, including its effects on cholinergic system agonists/antagonists, dopaminergic neurotransmission, the adrenergic system, and 5-HT3 serotonin receptors. One or more of these mechanisms may be responsible for the beneficial effects shown by thiadiazine compounds in experiments conducted to evaluate their activity in models of acute stress and acute myocardial infarction.