Multivariate spectrochemical analysis of interactions of three common Isatin derivatives to calf thymus DNA in vitro.

摘要: Interactions of Isatin and its derivatives, Isatin-3-isonicotinylhydrazone (IINH) Isatin-β-thiosemicarbazone (IBT), with calf thymus DNA (ctDNA) have been investigated to delineate pharmaceutical-physicochemical properties using UV-Vis/fluorescence/circular dichroism (CD) spectroscopy, viscosity measurements, multivariate chemometrics. IINH IBT molecules intercalate between base pairs DNA, hypochromism in UV absorptions, increase the CD positive band, sharp specific viscosity, displacement methylene blue Neutral Red dye complexes ctDNA, by molecules, respectively. The observed intrinsic binding constants (Kb[IBT-ctDNA] = 1.03 × 105 Kb[IINH-ctDNA] = 1.09 × 105 L mol-1) were roughly comparable other intercalators. In contrast, binds ctDNA via groove mode (Kb[Isatin-ctDNA] = 7.32 × 104 L mol-1) without any significant enhancement viscosity. fluorescence quenching was as static. spectra indicated that effectively absorbs into grooves leading transition from B C form. Thermodynamic parameters like enthalpy changes (∆H   0) calculated according Van't Hoff's equation, indicating spontaneous interactions. common soft/hard chemometric methods used not only resolve pure concentration spectral profiles components acquired but also calculate Stern-Volmer constants, stoichiometry, apparent (Ka), (Kb), thermodynamic parameters. Kb values for Isatin, IINH, 9.18 × 103, 1.53 × 105, 2.45 × 104 L mol-1, results obtained experimental-spectroscopic analyses showed acceptable agreement outlines.