Interaction between balofloxacin and DNA and the influence of Mg2+ on the interaction / 药学学报

<p><b>AIM</b>To study the binding mode of balofloxacin with DNA and evaluate the influence of Mg2+ on the binding between balofloxacin and DNA.</p><p><b>METHODS</b>Fluorescent spectroscopy was used to study the interaction of balofloxacin with DNA and to calculate the thermodynamic constants. UV-Vis spectra, DNA viscosity titration, competition experiment and the effect of dsDNA and ssDNA on the fluorescense intensity were used to identify the binding mode.</p><p><b>RESULTS</b>Balofloxacin interacted with CT-DNA with a quenching constant of (5.43 +/- 0.07) x 10(3) L x mol(-1). The interaction was exothermic with a Van't Hoff enthalply of - 8.03 kJ x mol(-1) x Mg2+ cation could enhance the quenching constant between balofloxacin and DNA.</p><p><b>CONCLUSION</b>Balofloxacin interacted with CT-DNA in the mode of groove binding and Mg2+ could mediate the binding of balofloxacin to DNA.</p>

Structural characterization of chlorobenzylidine / 药学学报

<p><b>AIM</b>To study the structure and crystal forms of chlorobenzylidine.</p><p><b>METHODS</b>Karl Fischer titrimetry, FTIR, thermal analysis, single and powder X-ray diffraction were used for the studies of the structure of chlorobenzylidine and for the identification of two forms of chlorobenzylidine.</p><p><b>RESULTS</b>Chlorobenzylidine and its diastereoisomer have been studied in this article. They can be distinguished by their different melting points. Two crystal forms of chlorobenzylidine (form A and form B) have also been detected and studied. Form A was studied by single-crystal X-ray diffraction, it crystallized in the triclinic system, space group P1(-), with two formula units per cell, is monohydrate. Karl Fischer titrimetry, FTIR, thermal analysis and powder X-ray diffraction were used for identification of the two forms.</p><p><b>CONCLUSION</b>The studies of structure and crystal forms of chlorobenzylidine are very useful for the clinical research and the selection of recrystallization process.</p>