Search

A series of new unique acetylene derivatives of 8-hydroxy- and 8-methoxyquinoline- 5-sulfonamide 3a - f and 6a - f were prepared by reactions of 8-hydroxy- and 8-methoxyquinoline- 5-sulfonyl chlorides with acetylene derivatives of amine. A series of new hybrid systems containing quinoline and 1,2,3-triazole systems 7a - h were obtained by reactions of acetylene derivatives of quinoline-5-sulfonamide 6a - d with organic azides. The structures of the obtained compounds were confirmed by 1 H and 13 C NMR spectroscopy and HR-MS spectrometry. The obtained quinoline derivatives 3a - f and 6a - f and 1,2,3-triazole derivatives 7a - h were tested for their anticancer and antimicrobial activity. Human amelanotic melanoma cells (C-32), human breast adenocarcinoma cells (MDA-MB-231), and human lung adenocarcinoma cells (A549) were selected as tested cancer lines, while cytotoxicity was investigated on normal human dermal fibroblasts (HFF-1). All the compounds were also tested against reference strains Staphylococcus aureus ATCC 29213 and Enterococcus faecalis ATCC 29212 and representatives of multidrug-resistant clinical isolates of methicillin-resistant S. aureus (MRSA) and vancomycin-resistant E. faecalis . Only the acetylene derivatives of 8-hydroxyquinoline-5-sulfonamide 3a - f were shown to be biologically active, and 8-hydroxy- N -methyl- N -(prop-2-yn-1-yl)quinoline-5-sulfonamide ( 3c ) showed the highest activity against all three cancer lines and MRSA isolates. Its efficacies were comparable to those of cisplatin/doxorubicin and oxacillin/ciprofloxacin. In the non-cancer HFF-1 line, the compound showed no toxicity up to an IC 50 of 100 µM. In additional tests, compound 3c decreased the expression of H3, increased the transcriptional activity of cell cycle regulators (P53 and P21 proteins), and altered the expression of BCL-2 and BAX genes in all cancer lines. The unsubstituted phenolic group at position 8 of the quinoline is the key structural fragment necessary for biological activity.

The optimized molecular structure, vibrational frequencies, corresponding vibrational assignments of 2-[(E)-2-(2-bromophenyl)ethenyl]quinoline-6-carboxylic acid have been investigated experimentally and theoretically using Gaussian09 software package. Potential energy distribution of the normal modes of vibrations was done using GAR2PED program. (1)H NMR chemical shifts calculations were carried out by using B3LYP functional with SDD basis set. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. MEP was performed by the DFT method and the predicted infrared intensities and Raman activities have also been reported. The calculated geometrical parameters are in agreement with that of similar derivatives. The title compound forms a stable complex with PknB as is evident from the binding affinity values and the molecular docking results suggest that the compound might exhibit inhibitory activity against PknB and this may result in development of new anti-tuberculostic agents., (Copyright © 2015 Elsevier B.V. All rights reserved.)

FT-IR and FT-Raman spectra of 2-[(E)-2-phenylethenyl]quinoline-5-carboxylic acid were recorded and obtained and analyzed. The vibrational wavenumbers were computed using DFT quantum chemical calculations. The geometrical parameters (SDD) of the title compound are in agreement with that of similar derivatives. Stability of the molecule arising from the hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital analysis. From the natural and Mulliken charges, it can be concluded that electrophilic substitution of the quinoline scaffold is more preferred than nucleophilic substitution. From the MEP map it is evident that the negative regions are mainly localized over the carbonyl group and are possible sites for electrophilic attack. The title compound forms a stable complex with PknB as is evident from the binding affinity values and the molecular docking study suggests that the compound might exhibit inhibitory activity against PknB., (Copyright © 2015 Elsevier B.V. All rights reserved.)

FT-IR and FT-Raman spectra of (2E)-N-(4-chloro-2-oxo-1,2-dihydroquinolin-3-yl)-3-phenylprop-2-enamide were recorded and analyzed experimentally and theoretically. The synthesis, (1)H NMR and PES scan results are also discussed. Nonlinear optical behavior of the examined molecule was investigated by the determination of first hyperpolarizability. The calculated HOMO and LUMO energies show the chemical activity of the molecule. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. From the MEP it is evident that the negative charge covers the carbonyl group and the positive region is over the NH group. The calculated geometrical parameters (SDD) are in agreement with that of similar derivatives. Molecular docking simulations against targets from Mycobacterium tuberculosis are reported and the results suggest that the compound might exhibit inhibitory activity against PknB., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Series of new ring-substituted styrylquinolines and two oxorhenium complexes were prepared and characterized. The compounds were analyzed using RP-HPLC to determine lipophilicity. Primary in vitro screening of the synthesized compounds was performed against fungal and bacterial strains. Some compounds were active against bacteria at micromolar level and against fungi at submicromolar level. Compounds 5,7-dichloro-2-[2-(2-ethoxyphenyl)vinyl]quinolin-8-ol expressed excellent antifungal activity comparable with or higher than the standard fluconazole as well as antibacterial activity against Staphylococcus strains comparable with or higher than the standards bacitracin, penicillin and ciprofloxacin. The structure-activity relationships are discussed., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

In this study a one step method for the preparation of substituted anilides of quinoline-2-carboxylic acid was developed. This efficient innovative approach is based on the direct reaction of an acid or ester with substituted anilines using microwave irradiation. The optimized method was used for the synthesis of a series of eighteen substituted quinoline-2-carboxanilides. The molecular structure of N-(4-bromophenyl)quinoline-2-carboxamide as a model compound was determined by single-crystal X-ray diffraction. It crystallizes in the monoclinic space group with four molecules within the unit cell and the total structure of the compound can be described as "a slightly screwed boat".

In this study, a series of thirty-five substituted quinoline-2-carboxamides and thirty-three substituted naphthalene-2-carboxamides were prepared and characterized. They were tested for their activity related to the inhibition of photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. Primary in vitro screening of the synthesized compounds was also performed against four mycobacterial species. N-Cycloheptylquinoline-2-carboxamide, N-cyclohexylquinoline-2-carboxamide and N-(2-phenylethyl)quinoline-2-carboxamide showed higher activity against M. tuberculosis than the standards isoniazid or pyrazinamide and 2-(pyrrolidin-1-ylcarbonyl)quinoline and 1-(2-naphthoyl)pyrrolidine expressed higher activity against M. kansasii and M. avium paratuberculosis than the standards isoniazid or pyrazinamide. The most effective antimycobacterial compounds demonstrated insignificant toxicity against the human monocytic leukemia THP-1 cell line. The PET-inhibiting activity expressed by IC(50) value of the most active compound N-benzyl-2-naphthamide was 7.5 μmol/L. For all compounds, the structure-activity relationships are discussed.

The structure-activity relationships of new quinoline based compounds were investigated. Quinoline-5,8-dione and styrylquinoline scaffolds were used for the design of potentially active compounds. The novel analogues had comparable antiproliferative activity to cisplatin when evaluated in a bioassay against the P388 leukemia cell line. However, these compounds appeared far less efficient against SK-N-MC neuroepithelioma cells. Analogues without the 5,8-dione structure but containing the 8-carboxylic acid group were also found to induce antiproliferative activity. Hydrophobicity as measured by HPLC did not correlate with antiproliferative activity.

The lack of the wide spectrum of biological data is an important obstacle preventing the efficient molecular design. Quinoline derivatives are known to exhibit a variety of biological effects. In the current publication, we tested a series of novel quinoline analogues for their photosynthesis-inhibiting activity (the inhibition of photosynthetic electron transport in spinach chloroplasts (Spinacia oleracea L.) and the reduction of chlorophyll content in Chlorella vulgaris Beij.). Moreover, antiproliferative activity was measured using SK-N-MC neuroepithelioma cell line. We described the structure-activity relationships (SAR) between the chemical structure and biological effects of the synthesized compounds. We also measured the lipophilicity of the novel compounds by means of the RP-HPLC and illustrate the relationships between the RP-HPLC retention parameter logK (the logarithm of capacity factor K) and logP data calculated by available programs.

The series of quinoline derivatives were prepared. The synthetic approach, analytical, and spectroscopic data of all synthesized compounds are presented. All the prepared derivatives were analyzed using the reversed-phase high performance liquid chromatography (RP-HPLC) method for the lipophilicity measurement. In the present study, the correlation between RP-HPLC retention parameter log K (the logarithm of capacity factor K) and various calculated log P data is shown. The relationships between the lipophilicity and the chemical structure of the studied compounds are discussed as well. The prepared compounds were tested for their in vitro antifungal activity. 2-[(3-Hydroxyphenylimino)methyl]quinolin-8-ol (8), 2-[(4-hydroxyphenylimino)methyl]quinolin-8-ol (9) and 2-[(2,5-dichloro-4-nitrophenylamino)methoxymethyl]quinolin-8-ol (10) showed in vitro antifungal activity comparable to or higher than that of the standard fluconazole. Structure-activity relationships among the chemical structure, the physical properties, and the biological activities of the evaluated compounds are discussed in the article.