Novel biologically active metallophthalocyanines as promising antioxidant-antibacterial agents: Synthesis, characterization and computational properties

Therapy and diagnosis of Alzheimer's disease: from discrete metal complexes to metal-organic frameworks

Alzheimer's disease (AD) is a neurodegenerative disorder affecting 44 million people worldwide. Although many issues (pathogenesis, genetics, clinical features, and pathological aspects) are still unknown, this disease is characterized by noticeable hallmarks such as the formation of β-amyloid plaques, hyperphosphorylation of tau proteins, the overproduction of reactive oxygen species, and the reduction of acetylcholine levels. There is still no cure for AD and the current treatments are aimed at regulating the cholinesterase levels, attenuating symptoms temporarily rather than preventing the AD progression. In this context, coordination compounds are regarded as a promissing tool in AD treatment and/or diagnosis. Coordination compounds (discrete or polymeric) possess several features that make them an interesting option for developing new drugs for AD (good biocompatibility, porosity, synergetic effects of ligand-metal, fluorescence, particle size, homogeneity, monodispersity, etc.). This review discusses the recent progress in the development of novel discrete metal complexes and metal-organic frameworks (MOFs) for the treatment, diagnosis and theragnosis of AD. These advanced therapies for AD treatment are organized according to the target: Aβ peptides, hyperphosphorylated tau proteins, synaptic dysfunction, and mitochondrial failure with subsequent oxidative stress.

Synthesis and Characterization of New-Type Soluble β-Substituted Zinc Phthalocyanine Derivative of Clofoctol

In this work, we have described the synthesis and characterization of novel zinc (II) phthalocyanine bearing four 2-(2,4-dichloro-benzyl)-4-(1,1,3,3-tetramethyl-butyl)-phenoxy substituents on the peripheral positions. The compound was characterized by elemental analysis and different spectroscopic techniques, such as FT-IR, ¹H NMR, MALDI-TOF, and UV-Vis. The Zn (II) phthalocyanine shows excellent solubility in organic solvents such as dichloromethane (DCM), n-hexane, chloroform, tetrahydrofuran (THF), and toluene. Photochemical and electrochemical characterizations of the complex were performed by UV-Vis, fluorescence spectroscopy, and cyclic voltammetry. Its good solubility allows a direct deposition of this compound as film, which has been tested as a solid-state sensing material in gravimetric chemical sensors for gas detection, and the obtained results indicate its potential for qualitative discrimination and quantitative assessment of various volatile organic compounds, among them methanol, n-hexane, triethylamine (TEA), toluene and DCM, in a wide concentration range.

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

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.

Novel axially symmetric and unsymmetric silicon(IV) phthalocyanines having anti-inflammatory groups: synthesis, characterization and their biological properties

New asymmetric Si(IV)Pc (1), monomeloxicammonotriethyleneglycolmonomethylether (phthalocyaninano)silicone, axially ligated with meloxicam as a non-steroidal anti-inflammatory drug (NSAID), or triethylene glycol monomethyl ether and symmetric Si(IV)Pc (2), diclofenac(phthalocyaninano)silicone, axially ligated with two diclofenac as NSAID, were synthesized and characterized as antioxidant and antimicrobial agents together with polyoxo-SiPc (3), ditriethyleneglycolmonomethylether(phthalocyaninano)silicone, and SiPc(OH)₂ (4), dihydroxy(phthalocyaninano)silicone. The photophysical and photochemical properties of these compounds were investigated. Then, antioxidant assays, including 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferrous ion chelating activities, were performed for these Si(IV) phthalocyanine derivatives (1, 2, 3 and 4). The highest DPPH scavenging activity of 73.48% was achieved with compound 2 and the highest ferrous chelating ability of 66.42% was obtained with compound 3. The results of the antioxidant assays indicated that Pc derivatives 1, 2 and 3 have remarkable superoxide radical scavenging activities, and moderate 2,2-diphenyl-1-picrylhydrazyl activities and metal chelating activities. The antimicrobial effects of the Si(IV) phthalocyanine compounds were studied against six pathogenic bacteria and two pathogenic microfungi. The results for the antimicrobial activity of these compounds indicated that Enterococcus faecalis (ATCC 29212) was the most sensitive microorganism and Pseudomonas aeruginosa (ATCC 27853) and Legionella pneumophila subsp. pneumophila (ATCC 33152) were the most resistant microorganisms against the tested compounds. The DNA cleavage ability and microbial cell viability of these compounds were studied. The studied compounds demonstrated excellent DNA nuclease activity and exhibited 100% cell viability inhibition at 500 mg L^-1. Also, the antimicrobial photodynamic therapy of the compounds was tested against Escherichia coli (ATCC 25922) and significant photodynamic antimicrobial activity was observed. In addition, the effect of phthalocyanines on biofilm inhibition produced by Staphylococcus aureus (ATCC 25923) was also tested and 3 showed excellent biofilm inhibition of 82.14%.

Photophysicochemical, sonochemical, and biological properties of novel hexadeca-substituted phthalocyanines bearing fluorinated groups

This study presents the preparation of a novel tetra-substituted phthalonitrile (1), namely, 3,6-bis(hexyloxy)-4,5-bis(4-(trifluoromethoxy)phenoxy)phthalonitrile (1) and its metal-free (2)/metal {M = Zn (3), Cu (4), Co (5), Lu(CH₃COO) (6), Lu (7)} phthalocyanines. A series of various spectroscopic methods (UV-vis, FT-IR, mass, and ¹H NMR spectroscopy) were performed for the characterization of the newly synthesized compounds. The potential of compounds 2, 3, and 6 as photosensitizing materials for photodynamic and sonophotodynamic therapies was evaluated by photophysical, photochemical, and sonochemical methods. The highest singlet quantum yields were obtained for the zinc phthalocyanine derivative 3 by performing photochemical and sonochemical methods. In addition, several biological activities of the new compounds 1-7 were investigated. The newly synthesized phthalocyanines exhibited excellent DPPH scavenging activity and also DNA nuclease activity. The antimicrobial activity of the new compounds was evaluated by the disc diffusion assay. Effective microbial cell viability inhibition was observed with phthalocyanine macromolecules. The photodynamic antimicrobial therapy of the phthalocyanines showed 100% bacterial inhibition when compared to the control. They also exhibited significant biofilm inhibition activity against S. aureus and P. aeruginosa. These results indicate that new phthalocyanines are promising photodynamic antimicrobial therapies for the treatment of infectious diseases.

Tetra-substituted phthalocyanines bearing thiazolidine derivatives: synthesis, anticancer activity on different cancer cell lines, and molecular docking studies

In the first step, (4R)-2-(2-hydroxyphenyl)thiazolidine-4-carboxylic acid (c) and 2-(2-(3,4-dicyanophenoxy)phenyl)thiazolidine-4-carboxylic acid (1) were prepared. Then, the peripherally tetra-substituted metallophthalocyanines [ZnPc (2), CuPc (3), and CoPc (4)] were synthesized by using 1. The structures of the obtained compounds were characterized by common spectroscopic methods. Aggregation behaviors of the tetra-substituted metallophthalocyanines (2-4) were investigated by UV-Vis and fluorescence spectroscopy in the presence/absence of soft metal ions. The electronic spectra of the newly synthesized metallophthalocyanines [ZnPc (2), CuPc (3), and CoPc (4)] were analyzed by the Bayliss method. The fluorescence quantum yield of diamagnetic ZnPc (2) was obtained in DMSO at room temperature. Also, the anticancer activity of the newly synthesized metallophthalocyanine derivatives was studied on C6, DU-145, and WI-38 cell lines and investigated using six concentrations (3.125; 6.25; 12.5; 50; 75; 100 μg L^-1). The cell cycle and apoptosis analyses of CuPc (3) were performed. In addition, the chemical and biological activities of 2-(2-(3,4-dicyanophenoxy)phenyl)thiazolidine-4-carboxylic acid (1) and its novel type metallophthalocyanines [ZnPc (2), CuPc (3), and CoPc (4)] were compared with many parameters obtained from the Gaussian software and molecular docking methods.

Synthesis, biological activity and docking calculations of bis-naphthoquinone derivatives from Lawsone

Some metabolic enzyme inhibitors can be used as Multi-target-Directed-Ligands (MTDL) in Medicinal chemistry therefore, synthesis and determination of alternative inhibitors are essential. In this study, novel bis-napthoquinone derivatives (5a-o) were synthesized through a multi-component cascade reaction of two molecules of 2-hydroxy-1,4-naphthoquinone with an aromatic aldehyde in basic media using triethylamine as a catalyst. This novel heterocyclic derivatives (5a-o) are applied to inhibit the carbonic anhydrase (hCA I and hCA II) isoform in low levels of nano molecules with Ki values exist between 4.62 ± 1.01 to 70.45 ± 9.03 nM for hCA I and for hCA II which is physiologically dominant K_is values are in the range of 5.61 ± 1.04 to 73.26 ± 10.25 nM. Further these novel derivatives (5a-o) efficiently inhibit AChE with Ki values in the range of 0.13 ± 0.02 to 3.16 ± 0.56 nM. The compounds are also applied for BChE with Ki values varying between 0.50 ± 0.10 to 9.23 ± 1.15 nM. For α-glycosidase, the most efficient Ki values of 5e and 5f are 76.14 ± 9.60 and 95.27 ± 12.55 nM respectively. Finally, molecular docking calculations against enzymes (acetylcholinesterase, butyrylcholinesterase, and the human carbonic anhydrase I and II) are compared using biological activities of heterocyclic derivatives. After these calculations, an ADME/T analysis is performed to study the future medicinal use of heterocyclic derivatives from lawsone.

α-Substituted phthalocyanines based on metal-induced H- or J-type aggregation for silver and palladium ions: synthesis, fluorescence, and antimicrobial and antioxidant properties

In this study, firstly, 3-(2,3-bis(hexadecylthio)propoxy)phthalonitrile (2) as a new phthalonitrile derivative was prepared. Then, new types of non-peripheral phthalocyanine derivatives [CuPc (3), ZnPc (4), and CoPc (5)] were synthesized by using this ligand. The synthesized new compounds were characterized by common spectroscopic methods such as FTIR, 1H-NMR, 13C-NMR, MALDI-TOF, UV-Vis and fluorescence spectroscopy. The H- or J-type aggregation behaviors of novel type metallophthalocyanines in the presence of valuable metal ions such as Ag(i) and Pd(ii) were investigated by UV-Vis and fluorescence spectroscopy. The quenching efficiency of the Ag(i) and Pd(ii) ions for ZnPc (4) was obtained using the Stern-Volmer equation and the quenching constant of ZnPc (4) towards Ag(i) and Pd(ii) ions was found to be 2.9 × 105 mol L-1 and 1.2 × 105 mol L-1, respectively. The binding constant (Ka) and binding stoichiometry (n) of Ag(i) and Pd(ii) ions for ZnPc (5) were calculated using a modified Benesi-Hildebrand equation, and were found to be 1.4 × 108 M-1 and 3.4 × 107 M-1, respectively. The binding ratio and free energy change of Ag(i) and Pd(ii) ions for ZnPc (4) were found to be 1.86, 1.54, -46.49 kJ mol-1 and -42.9 kJ mol-1, respectively. Also, the antioxidant properties of the synthesized novel type metallophthalocyanines and their Ag(i) and Pd(ii) ion doped aggregates were determined using three different methods: DPPH free radical scavenging activity, ferrous ion chelating activity and reducing power activity. Finally, the antibacterial and antifungal activities of phthalocyanine compounds synthesized within the scope of this study were determined by disc diffusion and macrobroth dilution methods and the effect of the doping of Ag(i) and Pd(ii) ions on the antibacterial activities of phthalocyanines was investigated.

Anti-quorum sensing activity in Pseudomonas aeruginosa PA01 of benzimidazolium salts: electronic, spectral and structural investigations as theoretical approach

Quorum sensing (QS) is a system used in the expression of virulence factors by many pathogenic bacteria, and blockage of the system is seen as a new and effective strategy in combating with resistant bacteria. The inhibition effects of two benzimidazolium salts, namely 1-(2-methylbenzonitrile)-3-benzylbenzimidazolium bromide (2) and 1-(N-methylphthalimide)-3-(4-methylbenzyl)benzimidazolium bromide (3), on quorum sensing-related virulence factors such as pyocyanin, elastase, biofilm formation and swarming motility, which is an opportunistic pathogen Pseudomonas aeruginosa PA01, were investigated in this study. The results show that the compound 3 has a significant inhibition on biofilm formation with 94%. Furthermore, the compounds 2 and 3 reduced swarming motility by 64-69% as well as pyocyanin production by 49-64% in P. aeruginosa PA01 without preventing bacterial growth in the tested concentrations. HF, B3LYP and M06-2X methods were used with 3-21 g, 6-31 g, sdd basis sets to compare the chemical activity of the compounds. Theoretically, ¹H NMR, ¹³C NMR and Infrared spectra of the compounds were calculated in the HF/6-31++g basis set. The biological activities of the relative compounds were theoretically studied against cancer proteins. Crystal structure of the BRCT repeat region from the breast cancer associated protein, ID: 1JNX, crystal structure of liver cancer protein, ID: 3WZE and crystal structure of lung cancer protein, ID: 5ZMA, were compared. In the docking studies, the best result was obtained with compound 2 against the lung cancer cell with a docking score parameter of -5.85.Communicated by Ramaswamy H. Sarma.

The biological activities, molecular docking studies, and anticancer effects of 1-arylsuphonylpyrazole derivatives

This work is devoted to definition of the direction of reaction between 1-benzenesulfonylimino pyridinium chloride and α- or β-halo-containing sulfamides, chloroacetic acid, 1-chloro-2,3-dihydroxypropane, etc. The optimal conditions for the synchronous reaction of heterocyclization are determined. Benzenesulfonyliminopyridinium chloride was obtained to form pyrazolopyridines with 1,2-polarophiles, and pyridazine pyridines with 1,3-polarophiles. These novel derivatives were found as effective inhibitors of the α-glycosidase with K_i values in the range of 13.66 ± 2.63-60.63 ± 12.71 nM. The molecules (II-X) against enzyme were compared theoretically with the help of molecular docking to compare biological activities. The results were compared with the numerical values of the parameters obtained from molecular docking calculations and found to be in great agreement with the experimental results. However, ADME analysis of molecules was performed. Also, the compounds exhibited significant anticancer effect depending on the doses administered.Communicated by Ramaswamy H. Sarma.

Enhanced Synergistic Antibacterial Activity through a Smart Platform Based on UiO-66 Combined with Photodynamic Therapy and Chemotherapy

Harmful bacteria have seriously threatened human health and wealth for a long time. Herein, a multifunctional drug delivery system based on UiO-66 was fabricated, and it showed potent synergistic antibacterial effects when used in conjunction with photodynamic therapy and chemotherapy. First, UiO-66-NH₂ was prepared via a facile solvothermal method. Then, carboxylic zinc phthalocyanine, a broad-spectrum photosensitizer, was connected to UiO-66-NH₂ by amidation. Next, synergistic chemical antibiotic linezolid was loaded in the pores, and lysozyme was coated on the surface by electrostatic interactions. In vitro antibacterial experiments were then carried out to evaluate the antibacterial effects of this system against three kinds of bacteria, Staphylococcus aureus, Escherichia coli, and methicillin-resistant S. aureus (MRSA). The combination of lysozyme, linezolid, and singlet oxygen generated by irradiation of the photosensitizers resulted in a potent antibacterial effect against S. aureus, E. coli, and even MRSA, which demonstrates the synergistic antibacterial efficacy of photodynamic therapy and chemotherapy.