Synthesis and anti-microbial activity of some 1- substituted amino-4,6-dimethyl-2-oxo-pyridine-3-carbonitrile derivatives

Antifungal and antibiofilm activities of chromones against nine Candida species

IMPORTANCE

The persistence of Candida infections is due to its ability to form biofilms that enable it to resist antifungals and host immune systems. Hence, inhibitions of the biofilm formation and virulence characteristics of Candida sp. provide potential means of addressing these infections. Among various chromone derivatives tested, four chromone-3-carbonitriles showed antifungal, antibiofilm, and antivirulence activities against several Candida species. Their mode of action has been partially revealed, and their toxicity is reported here using nematode and plant models.

Phthalimide as a versatile pharmacophore scaffold: Unlocking its diverse biological activities

Phthalimide, a pharmacophore exhibiting diverse biological activities, holds a prominent position in medicinal chemistry. In recent decades, numerous derivatives of phthalimide have been synthesized and extensively studied for their therapeutic potential across a wide range of health conditions. This comprehensive review highlights the latest developments in medicinal chemistry, specifically focusing on phthalimide-based compounds that have emerged within the last decade. These compounds showcase promising biological activities, including anti-inflammatory, anti-Alzheimer, antiepileptic, antischizophrenia, antiplatelet, anticancer, antibacterial, antifungal, antimycobacterial, antiparasitic, anthelmintic, antiviral, and antidiabetic properties. The physicochemical profiles of the phthalimide derivatives were carefully analyzed using the online platform pkCSM, revealing the remarkable versatility of this scaffold. Therefore, this review emphasizes the potential of phthalimide as a valuable scaffold for the development of novel therapeutic agents, providing avenues for the exploration and design of new compounds.

Antiproliferative activity of antimicrobial peptides and bioactive compounds from the mangrove Glutamicibacter mysorens

The Glutamicibacter group of microbes is known for antibiotic and enzyme production. Antibiotics and enzymes produced by them are important in the control, protection, and treatment of chronic human diseases. In this study, the Glutamicibacter mysorens (G. mysorens) strain MW647910.1 was isolated from mangrove soil in the Mangalore region of India. After optimization of growth conditions for G. mysorens on starch casein agar media, the micromorphology of G. mysorens was found to be spirally coiled spore chain, each spore visualized as an elongated cylindrical hairy appearance with curved edges visualized through Field Emission Scanning Electron Microscopy (FESEM) analysis. The culture phenotype with filamentous mycelia, brown pigmentation, and ash-colored spore production was observed. The intracellular extract of G. mysorens characterized through GCMS analysis detected bioactive compounds reported for pharmacological applications. The majority of bioactive compounds identified in intracellular extract when compared to the NIST library revealed molecular weight ranging below 1kgmole^-1. The Sephadex G-10 could result in 10.66 fold purification and eluted peak protein fraction showed significant anticancer activity on the prostate cancer cell line. Liquid Chromatography-Mass Spectrometry (LC-MS) analysis revealed Kinetin-9-ribose and Embinin with a molecular weight below 1 kDa. This study showed small molecular weight bioactive compounds produced from microbial origin possess dual roles, acting as antimicrobial peptides (AMPs) and anticancer peptides (ACPs). Hence, the bioactive compounds produced from microbial origin are a promising source of future therapeutics.

The Synthesis, Antimicrobial Activity, and Molecular Docking of New 1, 2, 4-Triazole, 1, 2, 4-Triazepine, Quinoline, and Pyrimidine Scaffolds Condensed to Naturally Occurring Furochromones

This study aims to synthesize a new series of furochromone derivatives, evaluate their antimicrobial properties, and improve the permeability of potent compounds to inhibit different types of bacteria and fungi. Hence, Substituted furo[3,2-g]chromene-6-carbonitrile (3a,b) readily form 7-amino-5-methyl-furo [3,2-g]chromene-6-carbonitrile (4a,b) via reduction using sodium borohydride in methanol. The same compounds of (4a,b) were used as starting materials for the synthesis of new furochromone derivatives such as furochromeno [2,3-d]pyrimidines, N- (6-cyano- 5-methyl-furochromene) acetamide, N-(6-cyano-5-methyl-furo chromene)-2-phenyl acetamide, N- (6-cyano-5-methyl-furochromene) formimidate, furochromeno[1,2,4]triazepin-5-amine, furochrom ene-6-carboxamide, furochromeno[1,2,4]triazolopyrimidines, and furochromeno[2,3-b]quinolin- 6-amine. The structures of the new compounds were determined using spectroscopy: Nuclear Magnetic Resonance (¹H, ¹³C), Mass spectra, Infrared, and elemental analysis. Molecular docking studies were conducted to investigate the binding patterns of the prepared compounds against DNA-gyrase (PDB 1HNJ). The results displayed that compounds furochromenotriazolopyrimidine (20a,b), furochromenoquinolin-6-amine (21a,b), furochromenotriazepin-amine (9a,b), and furo- chromenopyrimidine-amine (19a,b) were excellent antimicrobials.

Synthesis, Molecular Docking Study, and Cytotoxicity Evaluation of Some Novel 1,3,4-Thiadiazole as Well as 1,3-Thiazole Derivatives Bearing a Pyridine Moiety

Pyridine, 1,3,4-thiadiazole, and 1,3-thiazole derivatives have various biological activities, such as antimicrobial, analgesic, anticonvulsant, and antitubercular, as well as other anticipated biological properties, including anticancer activity. The starting 1-(3-cyano-4,6-dimethyl-2-oxopyridin-1(2H)-yl)-3-phenylthiourea (2) was prepared and reacted with various hydrazonoyl halides 3a–h, α-haloketones 5a–d, 3-chloropentane-2,4-dione 7a and ethyl 2-chloro-3-oxobutanoate 7b, which afforded the 3-aryl-5-substituted 1,3,4-thiadiazoles 4a–h, 3-phenyl-4-arylthiazoles 6a–d and the 4-methyl-3- phenyl-5-substituted thiazoles 8a,b, respectively. The structures of the synthesized products were confirmed by spectral data. All of the compounds also showed remarkable anticancer activity against the cell line of human colon carcinoma (HTC-116) as well as hepatocellular carcinoma (HepG-2) compared with the Harmine as a reference under in vitro condition. 1,3,4-Thiadiazole 4h was found to be most promising and an excellent performer against both cancer cell lines (IC₅₀ = 2.03 ± 0.72 and 2.17 ± 0.83 µM, respectively), better than the reference drug (IC₅₀ = 2.40 ± 0.12 and 2.54 ± 0.82 µM, respectively). In order to check the binding modes of the above thiadiazole derivatives, molecular docking studies were performed that established a binding site with EGFR TK.

Synthesis of a Pyridone-Based Phthalimide Fleximer and Its Characterization and Supramolecular Property Evaluation

In this study, a novel pyridone-based phthalimide fleximer, that is, ethyl 5-cyano-6-(3-(1,3-dioxoisoindolin-2-yl)propoxy)-4-(3-methoxyphenyl)-2-methylnicotinate, was synthesized, and its structure was established by the single-crystal X-ray diffraction method. The supramolecular self-assembly of the titled compound through noncovalent interactions was then investigated thoroughly. The titled compound crystallized with two symmetry-independent molecules (A and B, Z' = 2). In agreement with experimental observations, our density functional theory calculations also showed that the titled compound has a flexible motif and can occur in various conformations, including molecules A and B. The investigation of the supramolecular framework revealed that the molecules are notably bound by the nonclassical C-H···O and C-H···N hydrogen bonds and C-H···π interactions. Hirshfeld surface analysis was carried out to quantify the various intermolecular interactions. The dual anti-inflammatory activity of the tilted compound was also explored by molecular docking in the active sites of 5-LOX and COX-2 receptors, which revealed good binding affinities of -9.0 and -8.6 kcal/mol, respectively.

Preparation, DFT calculations, docking studies, antioxidant, and anticancer properties of new pyrazole and pyridine derivatives

Seven novel pyrazole derivatives (4a-g) and four novel starting compounds incorporating substituted pyridine moieties were synthesized successfully. Cell viability assay for the tested compounds was performed, and the inhibitory concentrationlogarithmic 50 (LogIC₅₀ ) values of the compounds were calculated after a 24-h treatment. Four of the examined compounds (3d, 3g, 4f, and 4g) showed comparable cytotoxic activity against CaCo-2 compared to the standard drug docetaxel at 0.1 and 1 μM concentrations. Although the LogIC₅₀  of docetaxel was -0.678 μM for CaCo-2 cells at 24 h, the LogIC₅₀ values of compounds were -0.794, -0.567, -0.657, and -0.498 μM, respectively. Five of the compounds (2d, 2g, 3d, 3g, and 4e) showed comparable cytotoxic activity against MCF-7 at 0.1 μM concentration compared to docetaxel (p < 0.05). Docking studies revealed the compounds have a good affinity to the active site of the human topoisomerase II β enzyme. The antioxidant capacities of all compounds were determined using both 1,1-diphenyl-2-picrylhydrazyl and metal chelation methods. Although the compounds did not show significant antioxidant activity, relatively effective are compounds 3c, 3d, and 3g, which are hydrazine derivatives with approximately 50% antioxidant activity of standard antioxidants at concentrations of 62.5 and 125 μg/ml.

Oxadiazole: A highly versatile scaffold in drug discovery

As a pharmacologically important heterocycle, oxadiazole paved the way to combat the problem associated with the confluence of many commercially available drugs with different pharmacological profiles. The present review focuses on the potential applications of five-membered heterocyclic oxadiazole derivatives, especially 1,2,4-oxadiazole, 1,2,5-oxadiazole, and 1,3,4-oxadiazole, as therapeutic agents. Designing new hybrid molecules containing the oxadiazole moiety is a better solution for the development of new drug molecules. The designed molecules may accumulate a biological profile better than those of the drugs currently available on the market. The present review will guide the way for researchers in the field of medicinal chemistry to design new biologically active molecules based on the oxadiazole nucleus. Antitubercular, antimalarial, anti-inflammatory, anti-HIV, antibacterial, and anticancer activities of various oxadiazoles have been reviewed extensively here.

Phthalimide Analogs Enhance Genotoxicity of Cyclophosphamide and Inhibit Its Associated Hypoxia

Cyclophosphamide (CP) is a mutagen that is used in cancer chemotherapy, due to its genotoxicity and as an immunosuppressive agent. Thalidomide (TH) is another cancer chemotherapeutic drug. In this study, the cytogenotoxicity and hypoxia modulatory activities of two phthalimide analogs of TH have been evaluated with/without CP. Both analogs have increased CP-stimulated chromosomal aberrations than those induced by TH, including gaps, breaks/fragments, deletions, multiple aberrations, and tetraploidy. The analogs have elevated the cytotoxic effect of CP by inhibiting the mitotic activity, in which analog 2 showed higher mitosis inhibition. CP has induced binucleated and polynucleated bone marrow cells (BMCs), while micronuclei (MN) are absent. TH and analogs have elevated the CP-stimulated binucleated BMCs, while only analogs have increased the CP-induced polynucleated BMCs and inhibited the mononucleated BMCs. MN-BMCs were shown together with mononucleated, binucleated, and polynucleated cells in the CP group. Both analogs have elevated mononucleated and polynucleated MN-BMCs, whereas in presence of CP, TH and analogs have enhanced mononucleated and binucleated MN-BMCs. The analogs significantly induce DNA fragmentation in a comet assay, where analog 1 is the strongest inducer. The treatment of mice with CP has resulted in a high hypoxia status as indicated by high pimonidazole adducts and high HIF-1α and HIF-2α concentrations in lymphocytes. Analogs/CP-treated mice showed low pimonidazole adducts. Both analogs have inhibited HIF-1α concentration but not HIF-2α. Taken together, the study findings suggest that both analogs have a higher potential to induce CP-genotoxicity than TH and that both analogs inhibit CP-hypoxia via the HIF-1α-dependent mechanism, in which analog 1 is a more potent anti-hypoxic agent than analog 2. Analog 1 is suggested as an adjacent CP-complementary agent to induce CP-genotoxicity and to inhibit CP-associated hypoxia.

Speculative assessment, molecular composition, PDOS, topology exploration (ELF, LOL, RDG), ligand-protein interactions, on 5-bromo-3-nitropyridine-2-carbonitrile

Computational calculations of 5-bromo-3-nitropyridine-2-carbonitrile (5B3N2C) on molecular structure and on energy are implemented using the 6-311++G(d,p) basis set by DFT/B3LYP method. The UV-Vis spectrum of 5B3N2C was obtained by TD-DFT with chloroform as a solvent. The analysis of molecular electrostatic potential (MEP) and frontier molecular orbital (FMO) were used to evaluate, the entire electron density and organic reactive sites of 5B3N2C. The electron-hole conversions were conjointly deliberated. Donor-acceptor interactions (NBO) analysis examines the intra-and intermolecular charge transfer, hyper conjugate interaction of the compound. The orbital molecular contributions are evaluated by density of states (DOS and PDOS). To discern the reactivity of the molecule, topology analyses were done. The biological prominence of the 5B3N2C molecule was investigated in a pertinent study of molecular docking with target protein 3CEJ exhibiting the centromere associated protein inhibitor property. Molecular Dynamics simulations were done to assess the stability of the complex. 5B3N2C physiochemical parameters were also compared to those of widely viable medications Ispinesib and Lonafarnib.

Synthesis, cytotoxic assessment, and molecular docking studies of 2,6-diaryl-substituted pyridine and 3,4- dihydropyrimidine-2(1H)-one scaffolds

Cancer is one of the main global health problems. In order to develop novel antitumor agents, we synthesized 3,4-dihydropyrimidine-2(1H)-one (DHPM) and 2,6-diaryl-substituted pyridine derivatives as potential antitumor structures and evaluated their cytotoxic effects against several cancer cell lines. An easy and convenient method is reported for the synthesis of these derivatives, employing cobalt ferrite (CoFe 2 O 4 @SiO 2 -SO 3 H) magnetic nanoparticles under microwave irradiation and solvent-free conditions. The structural characteristics of the prepared nanocatalyst were investigated by FTIR, XRD, SEM, and TGA techniques. In vitro cytotoxic effects of the synthesized products were assessed against the human breast adenocarcinoma cell line (MCF-7), gastric adenocarcinoma (AGS), and human embryonic kidney (HEK293) cells via MTT assay. The results indicated that compound 4r (DHPM derivative) was the most toxic molecule against the MCF-7 cell line (IC 50 of 0.17 μg/mL). Moreover, compounds 4j and 4r (DHPM derivatives) showed excellent cytotoxic activities against the AGS cell line, with an IC 50 of 4.90 and 4.97 μg/mL, respectively. Although they are pyridine derivatives, compounds 5g and 5m were more active against the MCF-7 cell line. Results showed that the candidate compounds exhibited low cytotoxicity against HEK293 cells. The kinesin Eg5 inhibitory potential of the candidate compounds was evaluated by molecular docking. The docking results showed that, among the pyridine derivatives, compound 5m had the most free energy of binding (-9.52 kcal/mol) and lowest Ki (0.105 μM), and among the pyrimidine derivatives, compound 4r had the most free energy of binding (-7.67 kcal/mol) and lowest Ki (2.39 μM). Ligand-enzyme affinity maps showed that compounds 4r and 5m had the potential to interact with the Eg5 binding site via H-bond interactions to GLU116 and GLY117 residues. The results of our study strongly suggest that DHPM and pyridine derivatives inhibit important tumorigenic features of breast and gastric cancer cells. Our results may be helpful in the further design of DHPMs and pyridine derivatives as potential anticancer agents.

Benzofuran derivatives and their anti-tubercular, anti-bacterial activities

Benzofuran is a fundamental structural unit in a variety of biologically active natural products, and its derivatives display various biological properties. Some benzofuran derivatives possess unique anti-tubercular and anti-bacterial action mechanism, and exhibit excellent in vitro and in vivo activities against both drug-sensitive and drug-resistant pathogens. Moreover, several benzofuran derivatives have already used in clinics for the treatment of various diseases. Thus, benzofuran is a useful pharmacophore to develop new anti-tubercular and anti-bacterial drugs. This review covers the recent advances of benzofuran derivatives as potential anti-tubercular and anti-bacterial agents, and the structure-activity relationship is also discussed to pave the way for the further rational development of this kind of derivatives.

L-Proline-Catalyzed Synthesis of Phthalimide Derivatives and Evaluation of Their Antioxidant, Anti-Inflammatory, and Lipoxygenase Inhibition Activities

A study was planned to synthesize the phthalimide derivatives as phthalimides have versatile biological activities. To synthesize the phthalimide derivatives, initially the reaction was optimized with various catalysts, and L-proline was found to be the best catalyst as it provided excellent yield. A series of phthalimide derivatives was synthesized by facile one-top reaction of phthalic acid with aryl amines under mild reaction conditions in the presence of L-proline as catalyst. Products were obtained in excellent yields and structurally characterized by 1H, 13C NMR, and mass spectral data. Products 1–7 were evaluated for antioxidant, anti-inflammatory, and lipoxygenase enzyme inhibition activities. Compounds 1 and 4 showed potent antioxidant activity under DPPH with IC50 values 27.3 and 25.0 μM when compared with the standard BHA (IC50 = 44.2 μM), respectively. Compounds 1 and 4 further showed strong lipoxygenase inhibition activity with IC50 values 21.34 and 20.45 μM when compared with standard baicalein (IC50 = 22.60 μM), respectively. Compound 2 was found to be promising and about equal to the used standard aspirin in the inhibition of bovine serum albumin denaturation, while other compounds showed weak-to-moderate % inhibition.

Preparation and Antibacterial Activity of Some New 4-(2-Heterylidenehydrazinyl)-7-chloroquinoline Derivatives

N-(4-Substituted phenyl)acetamides, which were prepared from acetic anhydride and p-substituted anilines, were utilized as precursors for reactions to Vilsmeier-Haack reagent to form 6-substituted-2-chloroquinoline-3-carbaldehydes 3a–c. Meanwhile, a similar reagent was applied to 1-[1-(4-substituted phenyl)ethylidene]-2-phenylhydrazines as substrates, which were synthesized from phenylhydrazine hydrochloride and p-substituted acetophenones, and 1,3-diarylpyrazole-4-carbaldehydes 3d–f were observed as a result. Reactions between the aldehydes 3a–f and 7-chloro-4-hydrazinylquinoline 2, obtained from reaction of 4,7-dichloroquinoline 1 and hydrazine hydrate, formed six new hydrazone compounds, namely, 4-{2-[(6-substituted-2-chloroquinolin-3-yl)methylidene]hydrazinyl}-7-chloroquinolines 4a–c and 4-(2-{[3-(4-substituted phenyl)-1-phenyl-1H-pyrazol-4-yl]methylene}hydrazinyl)-7-chloroquinolines 4d–f. The chemical structures of all synthesized compounds were elucidated by the analysis of IR, 1H, 13C-NMR, and HRMS spectral data. Additionally, all of the synthesized hydrazones were evaluated in terms of cytotoxic activity against four strains of bacteria and four strains of fungus at several concentrations of substrates. As a result, three of them, 4a–c, possess the good ability as growth inhibitor of Bacillus subtilis and Aspergillus niger at the concentration of 25 μg/mL and 50 μg/mL, respectively, while compound 4e only shows a cytotoxic activity against Aspergillus niger at the concentration of 25 μg/mL.

DMT efficiently inhibits hepatic gluconeogenesis by regulating the Gαq signaling pathway

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease with complicated pathogenesis and targeting gluconeogenesis inhibition is a promising strategy for anti-diabetic drug discovery. G protein-coupled receptors (GPCRs) are classified as distinct families by heterotrimeric G proteins, primarily including Gαs, Gαi and Gαq. Gαs-coupled GPCRs function potently in the regulation of hepatic gluconeogenesis by activating cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway and Gαi-coupled GPCRs exhibit inhibitory effect on adenylyl cyclase and reduce intracellular cAMP level. However, little is known about the regulation of Gαq-coupled GPCRs in hepatic gluconeogenesis. Here, small-molecule 2-(2,4-dimethoxy-3-methylphenyl)-7-(thiophen-2-yl)-9-(trifluoromethyl)-2,3-dihydropyrido[3',2':4,5]thieno[3,2-d]pyrimidin-4(1H)-one (DMT) was determined to suppress hepatic glucose production and reduce mRNA levels of gluconeogenic genes. Treatment of DMT in db/db mice decreased fasting blood glucose and hemoglobin A1C (HbA1c) levels, while improved glucose tolerance and pyruvate tolerance. Mechanism study demonstrated that DMT-inhibited gluconeogenesis by regulating the Gαq/phospholipase C (PLC)/inositol-1,4,5-triphosphate receptor (IP3R)-mediated calcium (Ca²⁺)/calmodulin (CaM)/phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (AKT)/forkhead box protein O1 (FOXO1) signaling pathway. To our knowledge, DMT might be the first reported small molecule able to suppress hepatic gluconeogenesis by regulating Gαq signaling, and our current work has also highlighted the potential of DMT in the treatment of T2DM.

Design, synthesis, and in vitro antituberculosis activity of benzo[6,7]cyclohepta[1,2-b]pyridine-1,3,4-oxadiazole derivatives

A new antitubercular agents, benzo[6,7]cyclohepta[1,2-b]pyridine-1,3,4- oxadiazole hybrids (6a-o), have been designed and synthesized involving oxidative cyclization of hydrazones by use of di(acetoxy)iodobenzene, characterized by IR,¹ H NMR,¹³ C NMR, and HRMS, and further confirmed by X-ray analysis. All the newly synthesized compounds 4a-o evaluated for their in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv (ATCC27294). Among the compounds tested, the compounds 4o (MIC: 1.56 μg/ml) and 4l, 4m (MIC: 3.125 μg/ml) are promising lead analogues and have shown lower cytotoxicity.

New Potential Antimalarial Agents: Design, Synthesis and Biological Evaluation of Some Novel Quinoline Derivatives as Antimalarial Agents

A novel series of dihydropyrimidines (DHPMs) 4a-j; 2-oxopyran-3-carboxylate 7a,b; 1-amino-1,2-dihydropyridine-3-carboxylate 8; and 1,3,4-oxadiazole derivatives 12 with quinolinyl residues have been synthesized in fairly good yields. The structure of the newly synthesized compounds was elucidated on the basis of analytical and spectral analyses. In vitro antimalarial evaluation of the synthesized quinoline derivatives against Plasmodium falciparum revealed them to possess moderate to high antimalarial activities, with IC50 values ranging from 0.014-5.87 μg/mL. Compounds 4b,g,i and 12 showed excellent antimalarial activity against to Plasmodium falciparum compared with the antimalarial agent chloroquine (CQ).

Synthesis, biological evaluation and molecular docking study of some novel indole and pyridine based 1,3,4-oxadiazole derivatives as potential antitubercular agents

A series of indole and pyridine based 1,3,4-oxadiazole derivatives 5a-t were synthesized and evaluated for their in vitro antitubercular activity against Mycobacterium tuberculosis H37Ra (MTB) and Mycobacterium bovis BCG both in active and dormant state. Compounds 5b, 5e, 5g and 5q exhibited very good antitubercular activity. All the newly synthesized compounds 5a-t were further evaluated for anti-proliferative activity against HeLa, A549 and PANC-1 cell lines using modified MTT assay and found to be noncytotoxic. On the basis of cytotoxicity and MIC values against Mycobacterium bovis BCG, selectivity index (SI) of most active compounds 5b, 5e, 5g and 5q was calculated (SI=GI50/MIC) in active and dormant state. Compounds 5b, 5e and 5g demonstrated SI values ⩾10 against all three cell lines and were found to safe for advance screening. Compounds 5a-t were further screened for their antibacterial activity against four bacteria strains to assess their selectivity towards MTB. In addition, the molecular docking studies revealed the binding modes of these compounds in active site of enoyl reductase (InhA), which in turn helped to establish a structural basis of inhibition of mycobacteria. The potency, low cytotoxicity and selectivity of these compounds make them valid lead compounds for further optimization.

Base-mediated synthesis of highly functionalized 2-aminonicotinonitriles from α-keto vinyl azides and α,α-dicyanoalkenes

A novel access to highly functionalized 2-aminonicotinonitriles via efficient annulations of α-keto vinyl azides and α,α-dicyanoalkenes is described.

Sulfamic acid-functionalized hydroxyapatite-encapsulated γ-Fe2O3 nanoparticles as a magnetically recoverable catalyst for synthesis of N-fused imidazole-quinoline conjugates under solvent-free conditions

γ-Fe₂O₃-HAp-(CH₂)₃-NHSO₃H was shown to be a powerful and reusable catalyst for the synthesis of N-fused imidazole-quinoline conjugates under solvent-free conditions.

Chemistry of Phosphorus Ylides: Part 41 Synthesis of Antimicrobial Agents from the Reaction of Aminoantipyrine, Coumarin- and Quinoline-carbaldehyde with Phosphacumulene and Phosphaallene Ylides

Pyrrolo-pyrazoles were obtained from the reaction between phosphacumulenes and aminoantipyrine, while the reaction with the phosphaallene (hexaphenylcarbodiphosphorane ylide) afforded the azaphosphole and pyrazolo-phosphanylidene. The aminocoumarin carbaldehyde gave the chromeno-phosphanylidene and the chromeno-pyridinone, when it was allowed to react with phosphacumulenes. The reaction of chloroquinoline carbaldehyde with the phosphacumulenes, gave chloroquinoline phosphanylidenecyclobutane, while the reaction with phosphaallene resulted in the formation of oxaphosphetane, phosphanylidene ethenyl- and oxaphosphetyl-quinoline. The structure of cyclobutanedione was confirmed by X-ray crystallography. The antimicrobial activity of the new compounds is also reported.

Synthesis of 4-aryl-6-indolylpyridine-3-carbonitriles and evaluation of their antiproliferative activity

A novel class of 6-indolypyridine-3-carbonitrilile derivatives were synthesized and evaluated for antiproliferative activities to establish structure-activity relationship. The synthesis was carried out through one-pot multicomponent reaction of 3-acetylindole, aromatic aldehydes, ethyl cyanoacetate, and ammonium acetate in the presence of piperidine as a catalyst, using a microwave irradiation method or a traditional thermal method. This was followed by chlorination for compounds 13a-e and subsequent nucleophilic substitution of the chlorine group by ethylenediamine at C₂ position of the pyridine ring. The antiproliferative activity of these new nicotinonitriles was evaluated against human ovarian adenocarcinoma (SK-OV-3), breast adenocarcinoma (MCF-7), and cervix adenocarcinoma (HeLa) cells. Among all compounds, 2-((2-aminoethyl)amino)-4-aryl-6-indolylnicotinonitriles series (15a, 15b, 15d, and 15e) exhibited higher antiproliferative activity cells with IC₅₀ values of 4.1-13.4 μM.

2-(4-Bromo-phen-yl)-4-(4-meth-oxy-phen-yl)-6,7,8,9-tetra-hydro-5H-cyclo-hepta-[b]pyridine

In the title compound, C₂₃H₂₂BrNO, the cyclo­heptane ring adopts a chair conformation. The pyridine ring makes dihedral angles of 58.63 (15) and 8.27 (16)° with the benzene rings. The dihedral angle between the benzene rings is 56.68 (17)°. The crystal packing features C—Br⋯π inter­actions [Br⋯centroid distances= 3.813 (2) and 3.839 (2) Å; C—Br⋯centroid = 126.25 (10) and 138.31 (10)°, respectively, forming a three dimensional supramolecular architecture.