Sulfonyl Hidrazones Compounds as Nucleic Acid Cleavage Agents
1FISCHER, F. L.; 1SEVERINO, P.C.; 2OLIVEIRA, K. N.; 2NUNES, R. J. and 1TERENZI, H.
1Departamento de Bioquímica,CCB; 2Departamento de Química,CFM, UFSC-SC.
Sulfonyl hydrazones are characterized by the group -SO2–NH–N=C-, with chemical and biological properties similar to sulfonamides. Sulfonyl hydrazones have a therapeutic interest, because of their antineoplasic, antibacterial, enzyme inhibitory activities and demonstrate protection against lipoperoxidation. In this work, three sulfonyl hydrazones compounds, with very similar structure but differing in the substitutent groups, were evaluated on their ability to cleave DNA. The compounds tested were: 4-(3,5-dioxo-10-oxa-4-azatricyclo[5.2.1.02,6]dec-8-en-4-yl)-N'-[(1E)-(4-nitrophenyl) methylene] benzenesulfono-hydrazone (K11); 4-(3,5-dioxo-10-oxa-4-azatricyclo [5.2.1.02,6] dec-8-en-4-yl)–N'-[(1E)-(4-methylphenyl) methylene] benzenesulfono-hydrazone (K14) and 1-methyl-4-(3,5-dioxo-10-oxa-4-azatricyclo [5.2.1.02,6] dec-8-en-4-yl)–N'-[(1E)-(4-nitrophenyl) methylene] benzenesulfono-hydrazone (K16).
The DNA cleavage study was performed by incubating the compounds with the plasmid DNA at different pH conditions and concentration. To test the optimum pH, compounds K11, K14 and K16 (125 mM and 230 mM) were incubated with 100 mM bp pBSK II DNA for 16 hours at 50ºC in four different buffers to final concentration of 50 mM: PIPES pH 6.5 and pH 7.0, HEPES pH 8.0 and CHES pH 9.0. After determination of the best conditions for the assay, kinetics test were performed. The final concentration in the reaction (volume 120 ml) was: 100 mM bp plasmid DNA, 125 mM and 230 mM of K11, K14 and K16 compounds, 50 mM PIPES pH 6.5. Samples were incubated at 50ºC, aliquots were taken off at different times (0, 1, 2, 4, 8 and 10 hours). Aliquots were submitted to agarose gel electrophoresis, staining with ethidium bromide and supercoilled and circular plasmid DNA were quantified using the LabWorks software. The best activity for DNA cleavage was observed at pH 6.5 and 50ºC. Compound K11 presented the highest activity, followed by K16 and K14. Differences in the substitutent group of sulfonyl hydrazones seem to play an important role in sulfonyl hydrazones/DNA cleavage. Other tests in anaerobic conditions; and in the presence of radical scavengers will be performed to characterize the mechanism involved in the DNA cleavage.
Financial support: CNPq, CAPES, FAPESC, MCT, TWAS, FINEP
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