Highly effective Ru/CMK-3 catalyst for selective reduction of nitrobenzene derivatives with H2O as solvent at near ambient temperature

Ru nanoparticles entrapped in ordered mesoporous carbon exhibit superior efficiency in the reduction of nitroarenes in water with hydrazine monohydrate.

Quantitative correlation of the in vitro biological effect with parameters of molecular complexation in mutagen-interceptor systems

According to the theory of interceptor-protector action a quantitative link between the physico-chemical parameters of molecular complexation and in vitro biological effect in aromatic drug-interceptor systems must exist. In the present communication such link between relative change in mutagenicity of IQ-type aromatic mutagens on addition of aromatic interceptor molecules with equilibrium hetero-association constants of mutagen-interceptor complexation has been found using the published in vitro data in bacteria cell systems.

RhNPs/SBA-NH2: a high-performance catalyst for aqueous phase reduction of nitroarenes to aminoarenes at room temperature

A RhNPs/SBA-NH₂ catalyst with <3 nm sized nanoparticles has been synthesized and used in the chemoselective hydrogenation of nitroarenes at room temperature in aqueous medium with N₂H₄·H₂O with high TOF.

Caffeine and other methylxanthines as interceptors of food-borne aromatic mutagens: inhibition of Trp-P-1 and Trp-P-2 mutagenic activity

Caffeine is one of the most important biologically active food components. In this article, we demonstrate that caffeine and other methylxanthines significantly reduce the mutagenic activity of two food-derived heterocyclic aromatic amines, Trp-P-1 and Trp-P-2 in the Salmonella typhimurium TA98 strain. Moreover, protection against Trp-P-1-induced mutagenicity was independent of liver S9 enzymatic fraction, suggesting that mechanisms other than modulation of mutagen bioactivation can contribute to the observed protective effects. UV-vis spectroscopy and computational studies revealed that methylxanthines intercept Trp-P-1 and Trp-P-2 in noncovalent molecular complexes, with association constants (KAC) in the 10(2) M(-1) range. Enthalpy values (ΔH about -30 kJ·mol(-1)) of mutagen-methylxanthine heterocomplexation obtained microcalorimetrically correspond to stacking (π-π) interactions. Finally, we demonstrated that the biological activity of Trp-P-1 and Trp-P-2 is strictly dependent on the presence of the mutagen in a free (unbound with methylxanthine) form, suggesting that mutagen sequestration in stacking heterocomplexes with methylxanthines can decrease its bioavailability and diminish its biological effects.