Dual-purpose both peripheral and non-peripheral triazole substituted ZnII, MgII and PbII phthalocyanines: Synthesis, characterization, photophysicochemical and acetylcholinesterase inhibitory properties

Abstract

Both peripheral and non-peripheral 4-(3,4-dimethoxyphenethyl)-5-ethyl-2H-1,2,4-triazol-3(4H)-one substituted zinc(II), magnesium(II) and lead(II) phthalocyanines were synthesized in this paper. Techniques used to illuminate the structure of these phthalocyanines included FT-IR, MALDI TOF, UV-Vis, NMR spectroscopy. The Zn(II)Pcs (p/np-ZnPcs), Mg(II)Pcs (p/np-MgPcs) and Pb(II)Pcs (p/np-PbPcs) exhibited outstanding solubility in common organic solvents such as 1,4-Dioxane, acetonitrile, chloroform, dichloromethane, dimethylformamide, dimethylsulphoxide, ethyl acetate and tetrahydrofurane. The photophysicochemical properties of Zn(II)Pcs, Mg(II)Pcs and Pb(II)Pcs were researched in DMSO. The positions of the substituents (peripheral or non-peripheral) and the effects of the central metal ions (Zn2+, Mg2+, Pb2+) on the photophysicochemical properties were reported by comparison. The singlet oxygen quantum yield values of Zn(II)Pcs, Mg(II)Pcs and Pb(II)Pcs ranged from 0.11 to 0.78 in DMSO. The newly synthesized peripherally tetra substituted zinc(II) phthalocyanine (p-ZnPc) exhibited high singlet oxygen generation in DMSO compared to unsubstituted zinc(II) phthalocyanine used as standard. These results indicate that the (p-ZnPc) can be a candidate as photosensitizer for PDT. Besides, the inhibitory properties of the compounds were determined using the spectrophotometric method on AChE and alpha-glucosidase. IC50 values showed that np-MgPc has highest inhibitory actions among the tested compounds on AChE and alpha-glucosidase.