Phthalocyanine conjugates with carbohydrates: synthesis and aggregation in aqueous solutions

The review is focused on the current state of the synthesis of glycosylated phthalocyanines and their precursors, mono-, di-, and tetraglycosyl phthalonitriles. Features of the synthesis of phthalogen conjugates with carbohydrates and the formation of related metal phthalocyanine complexes are discussed. The formation of aggregates of phthalocyanines in various media exerts a significant effect on the physicochemical and photochemical properties of phthalocyanine macrocycles, which is especially important in the practical use of phthalocyanines as photosensitizes. An aggregation of phthalocyanine conjugates in aqueous solutions strongly decreases the quantum yield of singlet oxygen, thus diminishing the biological activity of these compounds. Specific features of phthalocyanine conjugate aggregation with carbohydrates in aqueous solutions, organic solvents, and some their mixtures are analyzed.