Synthesis and structure-activity relationships of new 7-[3-(fluoromethyl)piperazinyl]- and -(fluorohomopiperazinyl)quinolone antibacterials

A copper-mediated cross-coupling approach for the synthesis of 3-heteroaryl quinolone and related analogues

An efficient and practical method for the direct cross-coupling between quinolones and a range of azoles was developed via copper-mediated C–H functionalization.

Metal-free intramolecular amination: one-pot tandem synthesis of 3-substituted 4-quinolones

3-Substituted 4-quinolones were synthesized using a one-pot metal-free strategy in moderate to quantitative yields. Carried out in dimethylsulfoxide (DMSO) via a sequential addition of materials, the methodology is tolerant of a wide range of functional groups and applicable to library synthesis.

A novel approach to determining physicochemical and absorption properties of 6-fluoroquinolone derivatives: experimental assessment

The ToSS MoDe approach is used to estimate the n-octanol/buffer partition coefficient, the apparent intestinal absorption rate constant and intestinal permeability from a 6-fluoroquinolone data set. Improved in silico methods for predicting a drug's ability to be transported across biological membranes and other biopharmaceutical properties is highly desirable to optimize new drug development. The physicochemical property (Log P) of 26 6-fluoroquinolone derivatives and the absorption properties (Log K(a) and Log P(eff)) of 21 derivatives were well described by the present approach. The models obtained confirm the important role of lipophilicity in the absorption process and its relation with the piperazinyl ring spectral moment and general local spectral moment. The normalized group contributions to each property, at the R4 and R5 positions of a 6-fluoroquinolone framework, were calculated. Principal factor analysis between these contributions and the Hammett and Hansch constant, molar refractivity and sterimol parameters was also carried out. Three principal factors explained 78% of the total variance and the correlation coefficients were higher than 0.98. The isocontribution zone analysis for the Log P and Log K(a) of Sarafloxacin and Sparfloxacin, used as external corroboration compounds, was carried out. The absorption rate constants (in situ rat gut technique) for these drugs were also evaluated, and the results were compared with the values predicted by theoretical models for evaluating predictive performance. The present approach proved to be a good method for studying the oral absorption of drug candidates in drug development studies.

Structure-absorption relationships of a series of 6-fluoroquinolones

The physicochemical constants and some structural parameters (topological, steric, and electronic) of eight third-generation monofluorate quinolones (six uncommercialized and two used clinically [ciprofloxacin and enrofloxacin]) were determined: pKa, intrinsic solubility (S0), chromatographic capacity factor, partition coefficient (P), valency molecular connectivity, molecular volume, molecular surface area, dipolar moment, and charges associated with each atom of the molecule. The apparent intestinal absorption rate constants (K(abs)) in rat (in vivo perfusion) and the MICs at which 90% of the isolates are inhibited (MIC90s) against 100 Escherichia coli strains were also determined. We sought to establish simple nonlinear and multiple linear correlations between K(abs), on the one hand, and lipophilic parameters and other physicochemical and structural parameters estimated. Of the nonlinear functions examined, the hyperbolic had the best correlation between K(abs) and P, which was in accordance with the Wagner-Sedman (J. G. Wagner and A. J. Sedman, J. Pharmacokinet. Biopharm. 1:23-50, 1973) equation, whereas, after application of the stepwise multiple linear regression method, a multiple linear correlation with some predictive value could be established only between K(abs) as a dependent variable and log P and log S0 as independent variables. In conclusion, the K(abs) and MIC90 of the quinolone CNV 8902 suggest that it is a sufficiently interesting compound to warrant the investigation of its potential therapeutic use orally.