Physical-chemical studies of new, versatile carbazole derivatives and zinc complexes: Their synthesis, investigation of in vitro inhibitory effects on alpha-glucosidase and human erythrocyte carbonic anhydrase I and II isoenzymes

In this study, two novel zinc-phthalocyanine complexes (4a and 6a), containing carbazole rings, were investigated. The first phthalocyanine 4a has been synthesized from 4-(2-(3-acetyl-9H-carbazol-9-yl)ethoxy at the peripheral position. Likewise, the second phthalocyanine 6a has been synthesized from 4-(2-(3-cinnamoyl-9H-carbazol-9-yl)ethoxy at the same position. The new phthalocyanines (Pcs) and their ligands are soluble in organic solvents, such as dimethylformamide, dimethyl sulfoxide, dichloromethane, ethyl acetate, and methanol/ethanol. The Zn (II) complexes were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance (NMR) (except C-13 NMR for complexes), elemental analysis, mass spectrometry, and UV-Vis spectroscopy. Also, photophysical and photochemical properties and cyclic voltammogram for the N-substituted carbazole zinc-Pcs have been reported. The evaluation of carbazole Zn (H) complexes (4a and 6a) and ligands (3, 4, 5, and 6) for in vitro alpha-glucosidase inhibitory activities was performed compared to standard drugs acarbose, and kinetic studies were also carried out to determine their inhibition modes. The inhibitory effects of these new Pcs (4a and 6a) and their ligands (3, 4, 5, and 6) on human erythrocytes carbonic anhydrase I (hCA I) and II (hCA H) isoenzymes were investigated. Moreover, in silico studies were also carried out to better investigate the interactions of N-substituted carbazole containing zinc Pcs with the active sites of hCA I and II isoforms.