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The synthesis of ethyl 4-oxo-1,4-dihydroquinoline-3-carboxylates (4, 5) was performed via the reaction of corresponding anilines with diethyl ethoxymethylenemalonate under conventional and also microwave promoted conditions. The treatment of 4 and 5 affor

Under CuBr·SMe2/PPh3 catalysis (5/10 mol-%) RMgCl (R = Me, Et, nPr, CH=CH2, nBu, iBu, nC5H11, cC6H11, Bn, CH2Bn, nC11H23) readily (–78 °C) undergo 1,4-addition to Cbz or Boc protected quinolin-4(1H)-ones to provide 2-alkyl-2,3-dihydroquinolin-4(1H)-ones (14 examples, 54–99 % yield). Asymmetric versions require AlEt3 to Boc-protected ethyl 6-substituted 4(1H)-quinolone-3-carboxylates (6-R group = all halogens, n/i/t-alkyls, CF3) and provide 61–91 % yield, 30–86 % ee; any halogen, Me, or CF3 provide the highest stereoselectivities (76–86 % ee). Additions of AlMe3 or Al(nC8H17)3 provide ≈ 45 and ≈ 75 % ee on addition to the parent (6-R = H). Ligand (S)-(BINOL)P–N(CHPh2)(cC6H11) provides the highest ee values engendering addition to the Si face of the 4(1H)-quinolone-3-carboxylate. Allylation and deprotection of a representative 1,4-addition product example confirm the facial selectivity (X-ray crystallography).

Human immunodeficiency virus type 1 (HIV-1) is a public health problem that affects over 38 million people worldwide. Although there are highly active antiretroviral therapies, emergence of antiviral resistant strains is a problem which leads to almost a million death annually. Thus, the development of new drugs is necessary. The viral enzyme reverse transcriptase (RT) represents a validated therapeutic target. Because the oxoquinolinic scaffold has substantial biological activities, including antiretroviral, a new series of 4-oxoquinoline ribonucleoside derivatives obtained by molecular hybridization were studied here. All synthesized compounds were tested against human immunodeficiency virus type 1 reverse transcriptase (HIV-1 RT), and 9a and 9d displayed the highest antiviral activities, with IC50 values of 1.4 and 1.6 μM, respectively. These compounds were less cytotoxic than AZT and showed CC50 values of 1486 and 1394 μM, respectively. Molecular docking studies showed that the most active compounds bound to the allosteric site of the enzyme, suggesting a low susceptibility to the development of antiviral resistance. In silico pharmacokinetic and toxicological evaluations reinforced the potential of the active compounds as anti-HIV candidates for further exploration. Overall, this work showed that compounds 9a and 9d are promising scaffold for future anti-HIV-1 RT drug design.

Background: Bovine herpesvirus type 5 is an important agent of meningoencephalitis in cattle and has been identified in outbreaks of bovine neurological disease in several Brazilian states. In recent years, oxoquinoline derivatives have become an important focus in antiviral drug research. Methods: The cytotoxicity and anti BoHV-5RJ42/01 activity of a set of synthetic 4-oxoquinoline derivatives 4a-k were assayed on Madin-Darby Bovine Kidney cell and antiviral activity by plaque reduction assay. Results: The most promising substance (4h) exhibited CC50 and EC50 values of 1,239 μM ±5.5 and 6.0 μM ±1.5, respectively, with an SI =206. Two other compounds 4j (CC50 = 35 μM ±2 and EC50 = 24 μM ±7.0) and 4k (CC50= 55 μM ±2 and EC50 = 24 μM ±5.1) presented similar inhibitory profile and selectivity indexes of 1.4 and 2.9, respectively. The results of the time-of-addition studies revealed expressive reduction of virus production (≥80%) in different stages of virus replication cycle except for compound 4h that slightly inhibited virus yield in the first 2 h post infection, but it showed expressive virus inhibition after this time. Conclusions: All three compounds slightly interact with the virus on the virucidal assay and they are not able to block virus attachment and penetration. Antiviral effect of oxoquinoline 4h was more prominent than acyclovir which leads us to suggest compound 4h as a promising molecule for further anti-BoHV-5 drug design.

Aurora kinases (AURKs) were identified as promising druggable targets for targeted cancer therapy. Aiming at the development of novel chemotype of dual AURKA/B inhibitors, herein we report the design and synthesis of three series of 4-anilinoquinoline derivatives bearing a sulfonamide moiety (5a-d, 9a-d and 11a-d). The percent inhibition of AURKA/B was determined for all target quinolines, then compounds showed more than 50percent inhibition on either of the enzymes, were evaluated further for their IC50 on the corresponding enzyme. In particular, compound 9d displayed potent AURKA/B inhibitory activities with IC50 of 0.93 and 0.09 μM, respectively. Also, 9d emerged as the most efficient anti-proliferative analogue in the US-NCI anticancer assay toward the NCI 60 cell lines panel, with broad spectrum activity against different cell lines from diverse cancer subpanels. Docking studies, confirmed that, the sulfonamide SO2 oxygen was involved in a hydrogen bond with Lys162 and Lys122 in AURKA and AURKB, respectively, whereas, the sulfonamide NH could catch hydrogen bond interaction with the surrounding amino acid residues Lys141, Glu260, and Asn261 in AURKA and Lys101, Glu177, and Asp234 in AURKB. Furthermore, N1 nitrogen of the quinoline scaffold formed an essential hydrogen bond with the hinge region key amino acids Ala213 and Ala173 in AURKA and AURKB, respectively.

Twenty-seven 3-(benzo[d]thiazol-2-yl)-4-aminoquinoline derivatives have been designed and synthesized as topoisomerase I inhibitors. The in vitro anti-proliferation evaluation against four human cancer cell lines (MGC-803, HepG-2, T24, and NCI-H460) and one normal cell line (HL-7702) indicated that most of them exhibited potent cytotoxicity. Among them, 5a was identified as the most promising candidate with a low IC50 value of about 2.20 ± 0.14 and was selected for further exploration. Spectroscopic analyses and agarose-gel electrophoresis assays indicated that 5a could interact with DNA and strongly inhibit topoisomerase I (Topo I). Further screening of the Topo I activity of compounds 5b, 5c, 5e, 5f, 5h, 5i, 5j, 5l, and 5n suggested that some of the compounds might exert quite a different cytotoxicity profile to that of 5a. Molecular modeling studies confirmed that 5a adopts a unique mode to interact with DNA and Topo I. Other molecular mechanistic studies suggested that the treatment of MGC-803 cells with 5a induces S phase arrest, up-regulates the pro-apoptotic protein, down-regulates the anti-apoptotic protein, activates caspase-3, and subsequently induces mitochondrial dysfunction so as to induce cell apoptosis. The in vivo efficiency of 5a was also evaluated on MGC-803 xenograft nude mice and the relative tumor growth inhibition was 42.4percent at 12 mg kg-1 without an obvious loss in the body weight. This journal is

The invention discloses a green efficient synthesis method of a quinolone compound. The method is as follows: Step 1, a dicarbonyl compound, triethyl orthoformate and an aniline compound react in theabsence of a solvent and a catalyst to obtain an enamine ester intermediate; and Step 2, the enamine ester intermediate is subjected to an intramolecular cyclization reaction under the action of a cyclization reagent diphenyl ether to obtain a quinolone parent ring compound. The purity of the product reaches up to 98.8%. the synthesis method of the invention has the following main beneficial effects: 1, the reaction in the Step 1 is efficient, and no catalyst or solvent is used so as to avoid generation of the three wastes and the yield is high; 2, the process in the step 2 is green, the cyclization reagent can be recycled and reused; and 3, the process is simple, the steps 1 and 2 can be carried out in the same reactor, and the quinolone compound is obtained after reaction and filtration.

Type-1 ryanodine receptor (RyR1) is a calcium-release channel localized on sarcoplasmic reticulum (SR) of the skeletal muscle, and mediates muscle contraction by releasing Ca2+ from the SR. Genetic mutations of RyR1 are associated with skeletal muscle diseases such as malignant hyperthermia and central core diseases, in which over-activation of RyR1 causes leakage of Ca2+ from the SR. We recently developed an efficient high-throughput screening system based on the measurement of Ca2+ in endoplasmic reticulum, and used it to identify oxolinic acid (1) as a novel RyR1 channel inhibitor. Here, we designed and synthesized a series of quinolone derivatives based on 1 as a lead compound. Derivatives bearing a long alkyl chain at the nitrogen atom of the quinolone ring and having a suitable substituent at the 7-position of quinolone exhibited potent RyR1 channel-inhibitory activity. Among the synthesized compounds, 14h showed more potent activity than dantrolene, a known RyR1 inhibitor, and exhibited high RyR1 selectivity over RyR2 and RyR3. These compounds may be promising leads for clinically applicable RyR1 channel inhibitors.

Carbonic anhydrases (CAs, EC 4.2.1.1) are crucial metalloenzymes that are involved in diverse bioprocesses. We report the synthesis and biological evaluation of novel series of benzenesulfonamides incorporating un/substituted ethyl quinoline-3-carboxylate moieties. The newly synthesised compounds were in vitro evaluated as inhibitors of the cytosolic human (h) isoforms hCA I and II. Both isoforms hCA I and II were inhibited by the quinolines reported here in variable degrees: hCA I was inhibited with KIs in the range of 0.966–9.091 μM, whereas hCA II in the range of 0.083–3.594 μM. The primary 7-chloro-6-flouro substituted sulphfonamide derivative 6e (KI = 0.083 μM) proved to be the most active quinoline in inhibiting hCA II, whereas, its secondary sulfonamide analog failed to inhibit the hCA II up to 10 μM, confirming the crucial role of the primary sulphfonamide group, as a zinc-binding group for CA inhibitory activity.

The synthesis, in vitro ligand binding study and in vivo Elevated Plus Maze test (EPM) of a series of pyrazolo[4,3-c]quinolin-3-ones (PQs) are reported. Multistep synthesis of PQs started from anilines and diethyl 2-(ethoxymethylene)malonate to give the q

The invention specifically discloses a 6-substituted-1-((1-substituted phenyl-1,2,3-triazole-4-yl)methyl)-4-carbonylquinoline-3-ethyl formate compound, and preparation and application thereof, belonging to the technical field of organic synthesis. The com

The present invention belongs to the technical field of organic synthesis, and specifically discloses 6-substituted-1-((1-substituted phenyl-1,2,3-triazole-4-yl)methyl)-4-carbonylquinoline-3-carboxylic compounds or a pharmaceutical salt thereof, and prepa

A novel series of hybrids of metronidazole and quinolones as antimicrobial agents were designed and synthesized. Most prepared compounds exhibited good or even stronger antimicrobial activities in comparison with reference drugs. Furthermore, these highly active metronidazole-quinolone hybrids showed appropriate ranges of pKa, log P and aqueous solubility to pharmacokinetic behaviors and no obvious toxicity to A549 and human hepatocyte LO2 cells. Their competitive interactions with metal ions to HSA revealed that the participation of Mg2+ ion in compound 7d-HSA association could result in a concentration increase of free compound 7d. Molecular modeling and experimental investigation of compound 7d with DNA suggested that possible antibacterial mechanism might be in relation with multiple binding sites between bioactive molecules and topo IV-DNA complex.

Thirty-one 4-oxoquinoline-3-carboxamides derivatives were synthesized and evaluated for their anti-fibrotic activities by the inhibition of TGF-β1-induced total collagen accumulation and anti-inflammatory activities by the inhibition of LPS-stimulated TNF-α production. Among them, three compounds (10a, 10l and 11g) exhibited potent inhibitory effects on both TGF-β1-induced total collagen accumulation and LPS-stimulated TNF-α production. Furthermore, oral administrations of 10l at a dose of 20 mg/kg/day for 4 weeks effectively alleviated lung inflammation and injury, and decreased lung collagen accumulation in bleomycin-induced pulmonary fibrosis model. Histopathological evaluation of lung tissue confirmed 10l as a potential, orally active agent for the treatment of pulmonary fibrosis.

Previously, quinolinium-based tetraazacyclophanes, such as UCL 1684 and UCL 1848, have been shown to be extraordinarily sensitive to changes in chemical structure (especially to the size of the cyclophane system) with respect to activity as potent non-peptidic blockers of the small conductance Ca 2+-activated K+ ion channels (SKCa). The present work has sought to optimize the structure of the linking chains in UCL 1848. We report the synthesis and SKCa channel-blocking activity of 29 analogues of UCL 1848 in which the central CH2 of UCL 1848 is replaced by other groups X or Y = O, S, CF2, CO, CHOH, CC, CHCH, CHMe to explore whether subtle changes in bond length or flexibility can improve potency still further. The possibility of improving potency by introducing ring substituents has also been explored by synthesizing and testing 25 analogues of UCL 1684 and UCL 1848 with substituents (NO2, NH2, CF 3, F, Cl, CH3, OCH3, OCF3, OH) in the 5, 6 or 7 positions of the aminoquinolinium rings. As in our earlier work, each compound was assayed for inhibition of the afterhyperpolarization (AHP) in rat sympathetic neurons, an action mediated by the SK3 subtype of the SK Ca channel. One of the new compounds (39, R7 = Cl, UCL 2053) is twice as potent as UCL 1848 and UCL 1684: seven are comparable in activity.

A single crystal X-ray diffraction and theoretical study has been carried out on mono hydrates of three 2H-pyrazolo[4,3-c]quinolin-3(5H)-one derivatives, namely 6-methyl-2-phenylpyrazolo[4,3-c]quinolin-3-one, 3, 6-methyl-2-(4- chlorophenyl)pyrazolo[4,3-c]quinolin-3-one, 4, and 8-methyl-2-(4-nitrophenyl) pyrazolo[4,3-c]quinolin-3-one, 5. The monohydrates were obtained on recrystallization from moist solvents. While there are three tautomeric forms possible for such pyrazolo[4,3-c]quinolin-3-one molecules, the sole form isolated in the solid [(X)×(H2O)] (X = 3, 4 and 5) compounds was the quinoloid form - the one calculated to be the most stable at the M06-2X/6-311++G(d,p) level of theory. Excellent agreement was found between the calculated and X-ray determined structures. Molecule 5 in [(5)×(H 2O)] is very near planar while both molecules 3 and 4 in their respective hydrates are much less so as a consequence of angles about 24 between the two aromatic rings. In each hydrate, the pyrazolo[4,3-c]quinolin-3-one molecule is bonded to three water molecules and each water molecule is likewise H-bonded to three pyrazolo[4,3-c]quinolin-3-one molecules. While the water molecules are H-bonded to 3 and 4 via the pyridinyl N and 2x the carbonyl O atoms, in [(5)×(H2O)] the H-bonds are to pyridinyl N, carbonyl O and a nitro O atoms. Calculations indicated that the found arrangement in [(5)×(H2O)] is more stable than one using the connections as found in [(3)×(H2O)] and [(4)×(H2O)]. While each of the hydrates possess strong N-H?O and O-H?O hydrogen bonds, and weaker C-H?π and π?π interactions, the supramolecular arrays are very different.

The 1,4-dihydro-4-oxoquinoline ribonucleoside, Neq135, is the first low micromolar trypanosomatidae inhibitor to show good ligand efficiency (0.28 kcal mol-1 atom-1) and good ligand lipophilicity efficiency (0.37 kcal mol-1/sup

A novel series of quinolone triazoles were synthesized and characterized by IR, NMR, MS and HRMS spectra. All the newly prepared compounds were screened for their antimicrobial activities against seven bacteria and four fungi. Bioactive assay manifested that most of new compounds exhibited good or even stronger antibacterial and antifungal activities against the tested strains including multi-drug resistant MRSA in comparison with reference drugs Norfloxacin, Chloromycin and Fluconazole. The preliminary interactive investigations of compound 6b with calf thymus DNA by fluorescence and UV-vis spectroscopic methods revealed that compound 6b could effectively intercalate DNA to form compound 6b-DNA complex which might block DNA replication and thus exert its antimicrobial activities.

A series of substituted 1,3,4-oxadiazole, 1,2,4-triazole, and 1,3,4-thiadiazole derivatives of the substituted 3-carboethoxy-1,4-dihydro-4- oxoquinoline have been synthesized through the reaction of the key intermediate thiosemicarbazide derivatives with different reagents. N′-Arylidene-4-oxo- 1,4-dihydroquinoline-3-carbohydrazides were also synthesized through the condensation reaction of the corresponding hydrazides with the appropriate aldehydes. Antimicrobial activity of some of the synthesized compounds was evaluated.

The emergence of a multidrug-resistant HIV-1 strain and the toxicity of anti-HIV-1 compounds approved for clinical use are the most significant problems facing antiretroviral therapies. Therefore, it is crucial to find new agents to overcome these issues. In this study, we synthesized a series of new oxoquinoline acyclonucleoside phosphonate analogues (ethyl 1- [(diisopropoxyphosphoryl)methyl]-4-oxo-1,4-dihydroquinoline-3-carboxylates 3a-3k), which contained different substituents at the C6 or C7 positions of the oxoquinoline nucleus and an N1-bonded phosphonate group. We subsequently investigated these compounds' in vitro inhibitory effects against HIV-1-infected peripheral blood mononuclear cells (PBMCs). The most active compounds were the fluoro-substituted derivatives 3f and 3g, which presented excellent EC 50 values of 0.4 ± 0.2 μM (3f) and 0.2 ± 0.005 μM (3g) and selectivity index values (SI) of 6240 and 14675, respectively.

A series of 2-(benzo[d]thiazol-2-yl)-8-substituted-2H-pyrazolo[4,3-c] quinolin-3(5H)-ones (3a-g) have been synthesized and evaluated for their in vitro antiproliferative activities against four human cancer cell lines: MDA-MB-435 (breast), HL-60 (leukemia), HCT-8 (colon) and SF-295 (central nervous system). The results showed that the compounds 3b (2-(benzo[d]thiazol-2-yl)-8- methyl-2H-pyrazolo[4,3-c]quinolin-3(5H)-one) and 3c (2-(benzo[d]thiazol-2-yl)-8- bromo-2H-pyrazolo[4,3-c]quinolin-3(5H)-one) exhibited good cytotoxicity for three cell lines with IC50 values lower than 5 μg/mL. Analysis of theoretical toxicity risks have shown medium tumorigenic and irritant risks related to 3b and 3c in contrast to doxorubicin, the positive control.

Due to the emerging role of protein kinase CK2 as a molecule that participates not only in the development of some cancers but also in viral infections and inflammatory failures, small organic inhibitors of CK2, besides application in scientific research, may have therapeutic significance. In this paper, we present a new class of CK2 inhibitors-3-carboxy-4(1H)-quinolones. This class of inhibitors has been selected via receptor-based virtual screening of the Otava compound library. It was revealed that the most active compounds, 5,6,8-trichloro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (7) (IC 50 = 0.3 μM) and 4-oxo-1,4-dihydrobenzo[h]quinoline-3-carboxylic acid (9) (IC50 = 1 μM), are ATP competitive (Ki values are 0.06 and 0.28 μM, respectively). Evaluation of the inhibitors on seven protein kinases shows considerable selectivity toward CK2. According to theoretical calculations and experimental data, a structural model describing the key features of 3-carboxy-4(1H)-quinolones responsible for tight binding to CK2 active site has been developed.

Several 1-[(2-hydroxy-ethoxy)methyl]-3-carbethoxy-4(1H)quinolones (2a-l) and l-[(2-hydroxy-ethoxy)methyl]-4(1H)quinolone-3-carboxylic acids (3a-j and 3l) were synthesized and 2a-j, 2l and 3a-j, 3l were evaluated against herpes simplex virus type 1 (HSV-1), employing a one-pot reaction: silylation of the desired quinolone (BSTFA 1% TMCS) followed by equimolar amount addition of 1,3-dioxolane, chlorotrimethylsilane and KI, at room temperature. The acyclonucleosides 2a-l were obtained in 40-77% yields. The esters 2a-j and 2l were subsequently converted into the corresponding hydroxyacids 3 in 40-70% yields. Attempts of hydrolysis of 2k produced only a mixture of degradation products. Antiviral activity of 2 and 3 on HSV-1 virus infection was assessed by the virus yield assay. Except for compounds 2i and 3e, the acyclonucleosides were found to reduce the virus yield by 70-99% at the concentration of 50 μM, being the acids, in general, more effective inhibitors than their corresponding esters. Compounds 3j and 2d exhibited antiviral activity against HSV-1 virus with EC50 of 0.7 ± 0.04 and 0.8 ± 0.09 μM, respectively. Both compounds were not toxic towards the Vero cell line.

A single step Gould-Jacob reaction between aromatic amines and diethyl ethoxymethylenemalonates (EMME) for the synthesis of 4-quinolones under solvent free microwave irradiation has been carried out and compared with classical heating.

Ribosylation reactions of previously silylated 3-carbethoxy-8-methyl-1,4-dihydro-4-oxoquinoline (6a) and 3-carbethoxy-6-methyl-1,4-dihydro-4-oxoquinoline (6b) with 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose (7), under Lewis acid catalysis, were studi