Syntheses, structural characterization, DNA-cleavage and antioxidant features of the new tetra-substituted organo-soluble non-peripherally Co^II, Cu^II, Zn^II and Mg^II phthalocyanines

This paper encompasses the synthesis, structural characterization, and evaluation of supercoiled pBR322 plasmid DNA-cleavage and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging properties of newly synthesized tetra-substituted Co^II (5), Cu^II (6), Zn^II (7) and Mg^II (8) phthalocyanines bearing 4-methyl-N-(4-morpholinophenyl)benzenesulfonamide units at non-peripheral sites of phthalocyanine skeleton. The structural characterization of these new metallated phthalocyanines were performed via UV-vis, elemental analysis, FT-IR (ATR sampling accessory), ¹H-NMR and ¹³C-NMR spectroscopic techniques (for 7 and 8) and MALDI-TOF mass spectral data. The new compounds (5–8) exhibited good solubility in common organic solvents, and as well as no sort of aggregation was perceived at studied concentrations and solvents. Compound 7 indicated oxidative photocleavage activities in the presence of H₂O₂, indicating the conversion of supercoiled pBR322 plasmid DNA to nicked circular form (19.90%) and linear form (4.40%). Compound 5 displayed the highest radical scavenging activities among the tested compounds. The DPPH-radical scavenging percentages of 5 ranged from 85.35 ± 2.45% (12.5 µM) to 95.38 ± 1.44% (100 µM). These compounds are favorable for further research, owing to a broad range of biological and pharmaceutical activities of morpholine scaffold.