In this study, we have reported on the synthesis and characterization of water-soluble phthalocyanines [M = 2H (2), Zn(II) (3), Ga(III)Cl (4)], containing sodium 2-mercaptoethanesulfonate substituents at the non-peripheral positions. All compounds were characterized by UV-vis, FT-IR and NMR spectroscopies, and MALDI-TOF mass spectra. Besides, spectral, photophysical (fluorescence quantum yields) and photochemical (singlet oxygen generation and photodegradation under light irradiation) properties of newly synthesized phthalocyanines were investigated in DMSO. These synthesized phthalocyanines [M = 2H (2), Zn(II) (3), Ga(III)Cl (4)] were found to be effective inhibitor compounds for the a-glycosidase, human carbonic anhydrase I and II (cytosolic, ubiquitous isozymes), hCA IX (transmembrane, cancerassociated isozyme), and cholinesterase enzymes with Ki values in the range of 0.66 +/- 0.08-2.31 +/- 0.24 mu M for alpha-glycosidase, 8.54 +/- 1.63 - 14.93 +/- 2.05 mu M for hCA I, 10.77 +/- 1.55 -13.74 +/- 0.97 mu M for hCA II, 10.55 +/- 0.98 -15.96 +/- 1.54 mu M for hCA IX, 102.77 +/- 16.04-158.43 +/- 26.95 mu M for BChE, and 114.75 +/- 15.05-174.31 +/- 35.43 mu M for AChE, respectively. Additionally, this work is also the first example of cancer-associated isozyme hCA IX inhibition by these novel phthalocyanines.