Solvent dependency of the UV-Vis spectrum of indenoisoquinolines: role of keto-oxygens as polarity interaction probes.

ABSTRACT: Indenoisoquinolines are the most promising non-campthotecins topoisomerase IB inhibitors. We present an integrated experimental/computational investigation of the UV-Vis spectra of the IQNs parental compound (NSC314622) and two of its derivatives (NSC724998 and NSC725776) currently undergoing Phase I clinical trials. In all the three compounds a similar dependence of the relative absorption intensities at 270 nm and 290 nm on solvent polarity is found. The keto-oxygens in positions 5 and 11 of the molecular scaffold of the molecule are the principal chromophores involved in this dependence. Protic interactions on these sites are also found to give rise to absorptions at wavelength <250 nm observed in water solution, due to the stabilization of highly polarized tautomers of the molecule. Th

SUBMITTER: Coletta A 

PROVIDER: S-EPMC3784438 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature