Synthesis and biological activity, photophysical, photochemical properties of tetra substituted magnesium phthalocyanine

The compound 4-(2-((1H-benzo[d]imidazol-2-yl) thio) phenoxy) phthalonitrile was obtained from the reaction of 2-nitrophenol, 4-nitrophthalonitrile and 2-mercaptobenzimidazole. This compound was reacted with magnesium Chloride (MgCl₂) to yield tetrakis-[(2-((1H-benzo[d]imidazol-2-yl) thio) phenoxy) phthalocyaninato] magnesium II. New compounds were characterized by UV-vis, ¹H NMR, ¹³C NMR, FTIR and Mass spectra. Electronic spectra aggregation study of magnesium phthalocyanine compound in various concentrations and diverse solvents was performed. Photoluminescence spectra of magnesium phthalocyanine in different solvents were investigated. The biological activities of 3 and 4 compounds were investigated. The results showed that 4 had excellent antioxidant and antidiabetic activities as 75.71% and 81.83%, respectively. 3 and 4 had deoxyribonucleic acid (DNA) cleavage ability and 4 caused a double-strand fracture in plasmid DNA at 100 and 200 mg/L. Both compounds showed antimicrobial activity and also 4 was more effective against pathogenic microorganisms than 3. Photodynamic antimicrobial therapy of test compound was also more effective than without irradiation. The highest biofilm inhibition of 3 and 4 was 78.28% and 98.49% for S. aureus and also 73.95% and 91.13% for P. aeruginosa, respectively. Finally, both compounds demonstrated %100 microbial cell viability inhibition at 100 mg/L. Overall, the study suggests that both 3 and 4 have potential for further development as therapeutic agents.