Chelerythrine chloride binding of guanosine in aqueous solution

In this work, the interaction between chelerythrine (CHE) and guanosine is studied using UV–vis and fluorescence measurements at various temperatures. The UV–vis spectra show that the increasing guanosine concentrations result in the decreasing absorption intensity and red shift of CHE E absorption band (267 nm). The fluorescence spectra are fitted to linear analysis, yielding a binding constant of 1.04 × 104 L/mol at 298.15 K of CHE with guanosine. Besides, with ΔrHmΘ=−8.26 kJ/mol, ΔrGmΘ=−22.90 kJ/mol, and ΔrSmΘ=49.38 J/(mol K) the interaction should be entropy-driven and exterothermic.