Effect of Axial Ligand Length on Biological and Anticancer Properties of Axially Disubstituted Silicon Phthalocyanines

Abstract

In this study, three new axially disubstituted silicon phthalocyanines (SiPc1-3) and their quaternized phthalocyanine derivatives (QSiPc1-3) were prepared and characterized. The biological properties (antioxidant, antimicrobial, antibiofilm, and microbial cell viability activities) of the water-soluble silicon phthalocyanines were examined, as well. A 1 % DMSO diluted with pure water was used as a solvent in biological activity studies. All the compounds exhibited high antioxidant activity. They displayed efficient antimicrobial and antimicrobial photodynamic therapeutic properties against various microorganisms, especially Gram (+) bacteria. Additionally, they demonstrated high antibiofilm activities against S. aureus and P. aeruginosa. In addition, 100 % bacterial reduction was obtained for all the studied phthalocyanines against E. coli viable cells. Besides, the DNA cleavage and binding features of compounds (QSiPc1-3) were studied using pBR322 DNA and CT-DNA, respectively. Furthermore, the human topoisomerase I enzyme inhibition activities of compounds QSiPc1-3 were studied. Anticancer properties of the water-soluble compounds were investigated using cell proliferation MTT assay. They exhibited anticarcinogenic activity against the human colon cancer cell line (DLD-1). Compounds QSiPc1 and QSiPc3 displayed a high anticarcinogenic effect on the DLD-1 cell line. The obtained results indicated that all the studied compounds may be effective biological agents and anticancer drugs after further investigations.

The effect of phthalocyanine's periphery on the biological activities of carbazole-containing metal phthalocyanines

“…Although the compounds displayed high activities with/without irradiation, the highest activity was obtained for the compound containing the longest axial length. 71…”

Water-soluble phthalocyanine photosensitizers for photodynamic therapy

“…The peripheral or nonperipheral positions and the central atom of the phthalocyanine ring can be made of these compounds as potential photosensitizers for biological and medical research areas [ 34 ]. Phthalocyanines are of great interest as photosensitizers for the treatment of malignant tumors in PDT.…”

“…Substitutions at peripheral or nonperipheral positions of the macrocycle for these compounds improve their solubility. In addition, the solubility of phthalocyanines in organic solvents and water is often enhanced by the addition of polar or ionic groups (-SO 3 − , -NR 3 + , -COO − ) at peripheral or nonperipheral positions [ 33 , 34 ]. Moreover, nonionic phthalocyanines contain polyethylene glycol/polyhydroxy, and carbohydrates can also gain their water solubility [ 35 ].…”

Sonophotochemical and photochemical efficiency of thiazole-containing metal phthalocyanines and their gold nanoconjugates

“…The structural modification of the phthalocyanine ring periphery with long/bulky substituents and the insertion of metal ions into the phthalocyanine ring core enhance the distance between the rings, diminish aggregation, and improve solubility. Further, these changes refine the characteristic properties of phthalocyanines and allow the use of these compounds for certain applications [ 16 – 25 ]. For instance, the presence of axial ligand(s) in the structure of metal phthalocyanines shifts the electronic absorption spectra of the phthalocyanines to longer wavelengths and makes them appropriate agents for near-IR/IR applications [ 10 , 25 ].…”

“…Further, these changes refine the characteristic properties of phthalocyanines and allow the use of these compounds for certain applications [ 16 – 25 ]. For instance, the presence of axial ligand(s) in the structure of metal phthalocyanines shifts the electronic absorption spectra of the phthalocyanines to longer wavelengths and makes them appropriate agents for near-IR/IR applications [ 10 , 25 ]. Additionally, the nature of central metal ions significantly affects the photophysical, sonophotochemical, and photochemical properties of the phthalocyanines.…”