Assessment of in vitro Cytotoxic, iNOS, Antioxidant and Photodynamic Antimicrobial Activities of Water-soluble Sulfonated Phthalocyanines

In(III) pyridinecarboxylate complexes: Composition, solution equilibria estimation, bioevaluation and interactions with HSA

Two In(III) - pyridinecarboxylates ([In(Pic)2(NO3)(H2O)] (InPic; HPic = picolinic acid), [In(HDpic)(Dpic)(H2O)2]·5H2O (InDpic; H2Dpic = dipicolinic acid), have been synthesized by one-step procedure. The complexes composition was confirmed by physicochemical analyses and X-ray diffraction confirmed molecular structure of both complexes. Moreover, complex species speciation was described in both systems by potentiometry and 1H NMR spectroscopy and mononuclear complex species were determined; [In(Pic)]2+ (logβ011 = 6.94(4)), [In(Pic)2]+ (logβ021 = 11.98(9)), [In(Dpic)]+ (logβ011 = 10.42(6)), [In(Dpic)2]- (logβ021 = 17.58(7)) and [In(Dpic)2(OH)]2- (logβ-121 = 10.18(6)). To confirm the complexes stability in 1 % DMSO, 1H NMR spectra were measured (immediately after dissolution up to 96 h). Antimicrobial and anticancer assays indicate a more significant sensitivity of S. aureus bacteria and MDA-MB-231 cancer cells to the InPic complex (IC50 = 25 and 340.7 μM) than to the InDpic (IC50 = 50 and 975.4 μM). The interaction and binding mechanism of picolinic/dipicolinic acid and their indium(III) complexes with HSA (human serum albumin) were studied using fluorescence and CD spectroscopy. The results confirmed that the studied compounds had bound successfully to HSA, and the binding parameters and constants (KSV, Kq, Kb) were calculated together with the number of binding sites. The binding forces were identified based on calculated thermodynamic parameters (ΔG, ΔH, ΔS). Synchronous spectra were used to study the microenvironment of Tyr and Trp residues and displacement assays revealed that site I was the preferred binding site. After binding, conformational changes were found to have occurred in the HSA molecule and the % α-helical content had decreased.

Assessing cytotoxic activities, theoretical and in silico molecular docking calculations of phthalocyanines bearing cinnamyloxy-groups

Cancer has been recognized as one of the deadliest diseases in the world in recent years. By chemically tailoring specific properties, anticancer agents can be prepared very effectively for the treatment of various cancer types. In this manner, as anticancer agents, a series of soluble metal-free and metallophthalocyanines carrying cinnamyloxy-groups at peripheral β-positions have been prepared. All synthesized phthalocyanines were characterized by various spectroscopic approaches such as ultraviolet - visible (UV - Vis), Fourier transform infrared (FT-IR), and matrix-assisted laser deionization/ionization time-of-flight mass spectroscopy (MALDI-TOF MS) techniques. These compounds are highly soluble in dimethyl sulfoxide (DMSO) and soluble in common organic solvents. The spectroscopic properties, cytotoxicity, and theoretical calculations of these complexes have been investigated. In cytotoxicity tests, compounds 1, 4, and 7 are the most active against HT-29 cell lines with IC50 values of 36.9 μM, 32.5 μM, and 51.1 μM, respectively. Also, the most and the least cytotoxic compounds against healthy CCD cell line is compounds 5 and 6 with the IC50 value of 13.4 μM and >250 μM, respectively. The PDB ID:4BQG target protein representing the HT-29 cancer cell line and the anti-cancer activities of phthalonitrile and its phthalocyanines were supported by molecular docking studies. Density Functional Theory (DFT) study supported the experimental results, including the spectral data, and implied that the compounds 5-7 are comparable by their characteristics, such as electronic properties, optical properties, electrostatic potentials, reactivity parameters, with the earlier studied compounds 2-4, which were successfully proved to be good candidates for cancer treatment.Communicated by Ramaswamy H. Sarma.

Cobalamin (Vitamin B12) in Anticancer Photodynamic Therapy with Zn(II) Phthalocyanines

Photodynamic therapy (PDT) is a curative method, firstly developed for cancer therapy with fast response after treatment and minimum side effects. Two zinc(II) phthalocyanines (3ZnPc and 4ZnPc) and a hydroxycobalamin (Cbl) were investigated on two breast cancer cell lines (MDA-MB-231 and MCF-7) in comparison to normal cell lines (MCF-10 and BALB 3T3). The novelty of this study is a complex of non-peripherally methylpyridiloxy substituted Zn(II) phthalocyanine (3ZnPc) and the evaluation of the effects on different cell lines due to the addition of second porphyrinoid such as Cbl. The results showed the complete photocytotoxicity of both ZnPc-complexes at lower concentrations (<0.1 μM) for 3ZnPc. The addition of Cbl caused a higher phototoxicity of 3ZnPc at one order lower concentrations (<0.01 μM) with a diminishment of the dark toxicity. Moreover, it was determined that an increase of the selectivity index of 3ZnPc, from 0.66 (MCF-7) and 0.89 (MDA-MB-231) to 1.56 and 2.31, occurred by the addition of Cbl upon exposure with a LED 660 nm (50 J/cm²). The study suggested that the addition of Cbl can minimize the dark toxicity and improve the efficiency of the phthalocyanines for anticancer PDT applications.

Zinc(II), Palladium(II), and Metal-Free Phthalocyanines Bearing Nipagin-Functionalized Substituents against Candida auris and Selected Multidrug-Resistant Microbes

Due to the rapidly increasing problem of antibiotic resistance in recent years, the use of phthalocyanines as photosensitizers with their superior properties in photodynamic antimicrobial therapy (PACT) applications has become important. In this study, magnesium(II) 1,4,8,11,15,18,22,25-octakis(4-[4-butoxycarbonylphenoxy]butyloxy)phthalocyanine was used in the demetalation reaction in trifluoroacetic acid, and subsequently subjected to metalation reaction in dimethylformamide with zinc(II) acetate and bis(benzonitrile)palladium(II) chloride towards zinc(II) and palladium(II) derivatives. Three phthalocyanines, including a demetalated one as well as two metalated, in the core with zinc(II) and palladium(II) were characterized using 1D and 2D NMR spectroscopy and mass spectrometry. In addition, all macrocycles were subjected to absorption and emission studies as well as photostability tests. In a photochemical study, zinc(II) and palladium(II) phthalocyanine complexes appeared to be efficient singlet oxygen generators. There were noted quantum yields of singlet oxygen generation for zinc(II) phthalocyanine derivative in DMF and DMSO at 0.55 and 0.72, whereas for palladium(II) complex at 0.73 and 0.77, respectively. Liposomal formulations of phthalocyanine derivatives were prepared, and their activity was evaluated against a broad spectrum of antibiotic-resistant microorganisms, such as methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli (ESBL+), Candida albicans resistant to fluconazole, C. auris, and against dermatophytes. Phthalocyanine palladium(II) complex showed the highest bactericidal activity against all antibiotic-resistant microorganisms, including reducing C. auris growth at 3.54 log.