Investigation of the antimycobacterial activity of 8-hydroxyquinolines.

A series of styrylquinolines and quinolineamides based on the 8-hydroxyquinoline moiety were investigated as potential antimycobacterial agents. The lipophilicity of the compounds was measured using RP-HPLC and the tests of their activity against Mycobacterium kansasii, the M. avium complex, M. smegmatis, M. abscessus, M. tuberculosis and M. avium paratuberculosis was performed. Several of the compounds that were obtained appeared to be more effective than isoniazid and ciprofloxacin. The 5,7-dinitro-8-hydroxyquinoline derivative possessed the highest potency against M. abscessus and M. Smegmatis, which was about twice as effective as ciprofloxacin, while 2-(2-hydroxystyryl)-8-hydroxyquinoline-7-carboxylic acid appeared to be comparable with the standard drugs that are against the M. avium complex. The structure activity relationships are discussed.

X-ray and molecular modelling in fragment-based design of three small quinoline scaffolds for HIV integrase inhibitors.

Crystal structures of three small molecular scaffolds based on quinoline, 2-methylquinoline-5,8-dione, 5-hydroxy-quinaldine-6-carboxylic acid and 8-hydroxy-quinaldine-7-carboxylic acid, were characterised. 5-Hydroxy-quinaldine-6-carboxylic acid was co-crystallized with cobalt(II) chloride to form a model of divalent metal cation-ligand interactions for potential HIV integrase inhibitors. Molecular docking into active site of HIV IN was also performed on 1WKN PDB file. Selected ligand-protein interactions have been found specific for active compounds. Studied structures can be used as scaffolds in fragment-based design of new potent drugs.

Ring-substituted 4-hydroxy-1H-quinolin-2-ones: preparation and biological activity.

In the study, a series of twelve ring-substituted 4-hydroxy-1H-quinolin-2-one derivatives were prepared. The procedures for synthesis of the compounds are presented. The compounds were analyzed using RP-HPLC to determine lipophilicity and tested for their photosynthesis-inhibiting activity using spinach (Spinacia oleracea L.) chloroplasts. All the synthesized compounds were also evaluated for antifungal activity using in vitro screening with eight fungal strains. For all the compounds, the relationships between the lipophilicity and the chemical structure of the studied compounds are discussed, as well as their structure-activity relationships (SAR).

Investigating biological activity spectrum for novel quinoline analogues 2: hydroxyquinolinecarboxamides with photosynthesis-inhibiting activity.

Two series of amides based on quinoline scaffold were designed and synthesized in search of photosynthesis inhibitors. The compounds were tested for their photosynthesis-inhibiting activity against Spinacia oleracea L. and Chlorella vulgaris Beij. The compounds lipophilicity was determined by the RP-HPLC method. Several compounds showed biological activity similar or even higher than that of the standard (DCMU). The structure-activity relationships are discussed.

Comparative molecular surface analysis (CoMSA) for virtual combinatorial library screening of styrylquinoline HIV-1 blocking agents.

We used comparative molecular surface analysis to design molecules for the synthesis as part of the search for new HIV-1 integrase inhibitors. We analyzed the virtual combinatorial library (VCL) constituted from various moieties of styrylquinoline and styrylquinazoline inhibitors. Since imines can be applied in a strategy of dynamic combinatorial chemistry (DCC), we also tested similar compounds in which the -C=N- or -N=C- linker connected the heteroaromatic and aromatic moieties. We then used principal component analysis (PCA) or self-organizing maps (SOM), namely, the Kohonen neural networks to obtain a clustering plot analyzing the diversity of the VCL formed. Previously synthesized compounds of known activity, used as molecular probes, were projected onto this plot, which provided a set of promising virtual drugs. Moreover, we further modified the above mentioned VCL to include the single bond linker -C-N- or -N-C-. This allowed increasing compound stability but expanded also the diversity between the available molecular probes and virtual targets. The application of the CoMSA with SOM indicated important differences between such compounds and active molecular probes. We synthesized such compounds to verify the computational predictions.