Novel amidine derivatives of benzanthrone: Effect of bromine atom on the spectral parameters.

Several new substituted amidine derivatives of benzanthrone were synthesized by condensation reaction from 2-bromo-3-aminobenzo[de]anthracen-7-one and appropriate aromatic or aliphatic amides. The novel benzanthrone derivatives were characterized by TLC analysis, NMR, IR, MS, UV/Vis, and fluorescence spectroscopy. The obtained derivatives have yellow or orange fluorescence in organic solvents. The solvent effect on photophysical behaviors of these dyes was investigated, and the results showed that the introduction of a bromine atom causes a blue-shift of the absorption and emission bands and decrease in the fluorescent quantum yield in comparison with unbromated analogues. The difference in the excited state and the ground state dipole moments was estimated by using the variation of Stokes shift and by semiempirical molecular calculations. The crystal structure and packing of four novel dyes has been revealed by the X-ray single crystal structure analysis.

[The effect of 3,5-dicarbomethoxyphenylbiguanide on the activity of antioxidant enzymes].

The effect of 3,5-dicarbomethoxyphenylbiguanide, which was selected with the Prediction of Activity Spectra of Substances (PASS) computer program, on the activity of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and glutathione transferase in the heart and the blood serum of rats with experimental rheumatoid arthritis was investigated. The studied parameters changed towards control values when the tested compound was injected in animals with the pathology. These results can be explained by the cardioprotective and antioxidant activity of the compound. The data obtained during the study may be used for the development of new preventive and therapeutic agents for the treatment of the rheumatoid arthritis.

Activity of Glutathione Antioxidant System and NADPH-Generating Enzymes in Rats with Experimental Rheumatoid Arthritis.

Induction of rheumatoid arthritis in rats was accompanied by an increase in diene conjugate content and glutathione reductase and glutathione peroxidase activities in muscles and blood serum. These changes can be related to mobilization of the glutathione reductase/glutathione peroxidase system coupled with intensification of free radical oxidation. In addition, activity of glucose-6-phosphodehydrogenase and NADP-dependent isocitrate dehydrogenase increased, which can be related to increased demand of NADPH for the glutathione reductase/glutathione peroxidase system. The content of reduced glutathione in muscles and blood serum decreased, probably, due to its utilization for ROS neutralization. Glutathione transferase activity decreased in rheumatoid arthritis, which can be related to shortness of reduced glutathione developing during oxidative stress. The observed shifts in parameters of free radical homeostasis in rheumatoid arthritis are probably associated with intensification of free radical oxidation.