A novel water soluble axially substituted silicon(IV) phthalocyanine bearing quaternized 4-(4-pyridinyl)phenol groups: Synthesis, characterization, photophysicochemical properties and BSA/DNA binding behavior

Comparing Singlet Oxygen Generation of Schiff Base Substituted Novel Silicon Phthalocyanines by Sonophotochemical and Photochemical Applications

Although the sonophotodynamic method has an effective therapeutic outcome for anticancer treatment compared with the photodynamic method, there are not enough related studies in the literature and this study aims to contribute to the development of sonophotodynamic studies. For this purpose, the Schiff base substituted silicon phthalocyanines were designed and synthesized as effective sensitizer candidates and the photophysicochemical and sonophotochemical features of the phthalocyanines were examined to increase singlet oxygen efficiency. The calculated ΦΔ values indicate that the contribution of substituent groups improved the production of singlet oxygen compared with silicon (IV) phthalocyanine dichloride (SiPcCI2 ) and also the sonophotochemical applications increased the singlet oxygen yields. The ΦΔ values (ΦΔ  = 0.76 for axially bis-{4-[(E)-(pyridin-3-ylimino)methyl]phenol} substituted silicon (IV) phthalocyanine (2a), 0.68 for axially bis-4-[(E)-{[(pyridin-3-yl)methyl]imino}methyl]phenol substituted silicon (IV) phthalocyanine (2b) in photochemical study) reached to ΦΔ  = 0.98 for 2a, 0.94 for 2b in sonophotochemical study. This article will enrich the literature on increasing singlet oxygen yield.

Amphiphilic Cationic Phthalocyanines for Photodynamic Therapy of Cancer

Effective interaction with biomembranes is essential for activity of photosensitizers; however, majority of them are highly charged symmetrical species. Amphiphilic cationic phthalocyanines differing in bulkiness of substitution on lipophilic part (-H, -SMe, -StBu) were therefore prepared. Compounds had high singlet oxygen production (ΦΔ =0.38-0.46, DMSO), good fluorescence emission (ΦF =0.21-0.26, DMSO), and log P values ranging -0.07-1.1 (1-octanol/PBS). Study of interaction with liposomes revealed that also bulky -StBu derivatives are able to enter biomembranes. Detail in vitro studies (toxicity, subcellular localization, type of cell death, and morphology) were performed. Compounds were characterized by excellent EC50 values in range of dozens of nM (HeLa, EA.hy926, MCF-7, HCT116), which were dependent on drug-light interval and reached plateau after 4 h on HeLa cells. Well-balanced lipophilicity with ability to interact with biomembranes rank these derivatives among perspective photosensitizers, even for vascular-targeted PDT (VTP) since they kill EA.hy926 without any preincubation time.

Fluoro-Substituted Metal Phthalocyanines for Active Layers of Chemical Sensors

Metal phthalocyanines bearing electron-withdrawing fluorine substituents were synthesized a long time ago, but interest in the study of their films has emerged in recent decades. This is due to the fact that, unlike unsubstituted phthalocyanines, films of some fluorinated phthalocyanines exhibit the properties of n-type semiconductors, which makes them promising candidates for application in ambipolar transistors. Apart from this, it was shown that the introduction of fluorine substituents led to an increase in the sensitivity of phthalocyanine films to reducing gases. This review analyzes the state of research over the last fifteen years in the field of applications of fluoro-substituted metal phthalocyanines as active layers of gas sensors, with a primary focus on chemiresistive ones. The active layers on the basis of phthalocyanines with fluorine and fluorine-containing substituents of optical and quartz crystal microbalance sensors are also considered. Attention is paid to the analysis of the effect of molecular structure (central metal, number and type of fluorine substituent etc.) on sensor properties of fluorinated phthalocyanine films.

Experimental and theoretical investigation of water-soluble silicon(IV) phthalocyanine and its interaction with bovine serum albumin

Photodynamic therapy (PDT) has drawn a great scientific attention to cancer treatment over the last decades. However, the bottleneck for the PDT is to find good photosensitizers (PSs) with greater water solubility, no aggregation, and fast discharge from the body. Therefore, there are still a big scientific desire for the synthesizing new rational PSs for treatment of cancer by PDT technique. In favor of improving the competence of PDT, an axially bis[4-(diphenylamino-1,1'-biphenyl-4-ol)] substituted silicon(IV) phthalocyanine (3) was converted to its water-soluble quaternized derivative (3Q). Their structures were fully characterized by single-crystal X-ray diffraction, elemental analysis, and different spectroscopic methods such as FT-IR, UV-Vis, MALDI-TOF, and 1H-NMR. The photophysical properties such as fluorescence quantum yields and lifetimes, and the photochemical properties such as singlet oxygen generation of both phthalocyanines were investigated. Ground and excited-state calculations were performed to explain the observed electronic absorption spectra. The addition of the 4-diphenylamino-1,1'-biphenyl-4-ol groups on the axially positions of the silicon(IV) phthalocyanine increased the singlet oxygen quantum yield from 0.15 to around 0.20. Especially quaternized compound 3Q showed high singlet oxygen quantum yield of 0.26 in water solution. In addition, a spectroscopic investigation of the binding behavior of the quaternized silicon (IV) phthalocyanine complex to bovine serum albumin (BSA) is also studied in this work, confirming the possible interaction. Further theoretical calculations were carried out to find out the plausible-binding regions of the BSA protein. Axially bis[4-(diphenylamino-1,1'-biphenyl-4-ol)] substituted silicon(IV) phthalocyanine (3) was converted to its quaternized water soluble derivative (3Q). The photophysical properties such as fluorescence quantum yields and lifetimes, and the photochemical properties such as singlet oxygen generation of both phthalocyanines were investigated. In addition, a spectroscopic investigation of the binding behavior of the quaternized silicon (IV) phthalocyanine complex to bovine serum albumin (BSA) is also studied in this work, confirming the possible interaction. Further theoretical calculations were carried out to find out the plausible binding regions of the BSA protein.