Journal of Porphyrins and Phthalocyanines

To improve the cancer targeting and anticancer efficacy, the multifunctional Eu-based metal-organic framework (EuBTC) is post-synthetically modified with a targeting moiety folic acid and a zinc phthalocyanine photosensitizer. In addition, this nanosphere is also applied as a drug delivery system to load the chemical drug doxorubicin. Electron microscopy, powder X-ray diffraction and infrared spectometry demonstrated the formation of these multifunctional nanospheres (DOX). Our nanospheres kept the high singlet oxygen quantum yield of zinc phthalocyanine. Additionally, Cell viability experiments demonstrated the biosafety of EuBTC and the enhanced anticancer effect of DOX@FA-EuBTC-Pc under light irradiation. In short, these well-arranged DOX@FA-Eu-BTC-Pcs exhibit as promising drug delivery systems for enhanced targeted anticancer therapy.

Photoinduced electron transfer has been investigated in porphyrin anthraquinone (ZnTTP-AQ) donor–acceptor dyads having either ester (ZnTTP-AQ1) or ether (ZnTTP-AQ2) linkages. Both dyads were characterized by spectroscopic and electrochemical methods. Absorption spectra show absence of any ground state interaction between the porphyrin and anthraquinone moieties. The quenched fluoresence and lifetime indicate electron transfer from the porphyrin to the anthraquinone moiety. The quenching is more pronounced in ZnTTP-AQ1 with ester linkage, suggesting efficient electronic coupling compared to the ether linkage in ZnTTP-AQ2. Computational analysis and frontier molecular orbitals confirmed the formation of charged separated state por${{}^{•}}^{+}$AQ${}^{•-}$. The electron transfer rates ($k_{ET})$ of these triads are found in the range 0.43 × 10⁸ to 10.52 × 10⁹ s${}^{-1}$ and are found to be solvent polarity dependent.

Visible and infrared spectroelectrochemistry of Fe(OEPone)(NO) (H₂OEPone = octaethylporphinone) were examined in methylene chloride and THF. The visible spectra of Fe(OEPone)(NO) were similar in both solvents. Unlike other ferrous porphyrin nitrosyls, a six-coordinate complex was formed with THF as a ligand. This led to two nitrosyl bands in the infrared spectrum. The absorbance of these bands depended on the concentration of THF in the solution. Solvation and coordination effects on the carbonyl and nitrosyl bands were observed for both the nitrosyl and reduced-nitrosyl complexes. DFT calculations were carried out to interpret the spectral changes.

Marquette University, Raynor Memorial Libraries, Chemistry Research Data: https://epublications.marquette.edu/chem_data/1/

BODIPYs with 3-thienyl and 4-acetamido phenyl groups substituted at the meso-position are subjected to regioselective bromination using three equivalents of $N$-bromosuccinimide (NBS) to yield their 2-mono and 2,6-di bromoderivatives. Their photophysical, electrochemical and antimicrobial properties are investigated. This paper presents a mechanistic investigation of the antibacterial effect of brominated BODIPYs, particularly against Staphylococcus aureus. Fluorescence microscopic images reveal that the compounds are internalized effectively within the bacterial cells, making it an ideal antibacterial drug. Morphological analysis of the bacterial cells after the treatment with the test compounds showed that the compounds did not affect the cell membrane or cell wall and the antibacterial effect of these compounds is achieved via a different mechanism. The most effective compound was selected to explore the target of action. Molecular docking studies were performed on 22 selected proteins in S. aureus and the in silico results were validated by in vitro experiments. It was observed that the supercoiling activity of DNA gyrase was completely inhibited by the 2,6-dibromo-1,3,5,7-tetramethyl-8-(4-acetamido)-4-bora-3a,4a-diaza-$s$-indacene, 3c by forming H-bonds with the ASP 81 residue of the enzyme.

In this paper, three $\beta$,${\beta }^{\prime }$-conjugated cationic porphyrin compounds were designed and synthesized. The structure of the intermediates and desired porphyrins were confirmed by UV, IR, ¹H NMR, MS and elemental analysis. The interaction modes between these porphyrins and ct-DNA were studied by UV-vis spectroscopy and fluorescence emission spectroscopy. The results showed that PCP 1 had an external binding mode with DNA at low DNA concentration and could intercalate DNA with the increase of concentration. PCP 2 interacted with DNA through an external binding mode, and PCP 3 could insert into DNA. The binding constants ($K)$ between PCP1$\sim$PCP3 and ct-DNA were calculated to be 8.41 × 10⁴, 7.33 × 10⁴ and 4.14 × 10⁴ M${}^{-1}$, respectively. The singlet oxygen (¹O${}_2)$ generation of PCP1$\sim$PCP3 was determined by the 1,3-diphenylisobenzofuran (DPBF) method using tetrapyridylporphyrin (H₂TMPyP) as a reference. The ¹O₂ generation rate of PCP1$\sim$PCP3 followed the order of PCP2 >PCP1>H₂TMPyP >PCP3. Subsequently, the photocleavage effect of porphyrins on pBR322 plasmid DNA was studied by gel electrophoresis. At 10.0 $\mu$M, PCP1 and PCP2 could cleave DNA completely. At 2.0 $\mu$M, the cleavage rate of DNA by PCP3 was 57.5%, which was significantly higher than that of H₂TMPyP (38.8%). These results verified that the amount of cationic ions in the porphyrin structure could affect the binding modes of porphyrins with DNA and their cleavage ability of DNA.

3,/3,5-Dithienosilole-vinyl-BODIPYs were readily synthesized through Knoevenagel condensation reactions. Spectroscopic properties of two dyes in various solvents were investigated. Dyes 1 and 2 show an absorption maxima at 620 and 738 nm with absorption coefficient of 60900 and 77900 ${\text{M}}^{-1}·$ cm${}^{-1}$ in DCM, respectively. Significant red shifts of the main spectral bands are observed relative to that of the parent 1,3,5,7-tetramethyl-BODIPY. TD-DFT calculations reproduce the spectral shifts and experimental spectra.

Condensation of pyrrole with various aldehydes in the presence of BF₃•etherate as an acid catalyst in water provides good yield of some dipyrromethanes. Prolongation of the reaction time with aldehydes substituted by electron-donating (mesityl) or electron-withdrawing (2,6-dichlorophenyl) groups on the ortho positions of the phenyl did not lead to decomposition or scrambling. Manganese trans disubstituted porphyrin complexes which derive from various dipyrromethanes and manganese tetraaryl porphyrin complexes including various substituents with different steric and electronic properties show good catalytic activity in epoxidation of alkenes by NaIO₄ in the presence of imidazole (ImH). The study of steric and electronic effects of the catalysts on the epoxidation of olefins shows that Mn-porphyrin complexes with more bulky and electron-releasing groups on meso phenyls could increase the epoxidation yield of most alkenes.

In recent years, great interest has been focused on the use of photosensitizers (PS) for photodynamic therapy (PDT) as safe and effective anti-tumor drugs. As a good lysosomal-targeted drug, folic acid (FA) is highly interesting as well. $N$-methylpyridylporphyrin tailed with folate conjugate (Me-Por-FA) was newly designed and synthesized and the structure was confirmed by UV-vis, IR, ¹H NMR, MS and elemental analysis. The interaction of this porphyrin with calf thymus DNA was the intercalative binding mode, which was confirmed by ultraviolet and fluorescence spectra, and the binding constants $K$ was 6.24 × 10⁴ L/mol. The singlet oxygen (¹O${}_2)$ generated by Me-Por-FA was determined by 1, 3-diphenylisobenzofuran (DPBF) method using tetrapyridylporphyrin (H${}_2$TMPyP) as a comparison with the following order: H₂TMPyP > Me-Por-FA. Stained with LysoTracker${}^{\text{®}}$ Green DND-26, Me-Por-FA was mainly distributed over the lysosomes during 4 h, but H${}_2$TMPyP was not. This suggests that Me-Por-FA could be developed as a targeted photosensitizer for precise photodynamic therapy.

Based on the results of a quantum chemical calculation using the DFT method, the possibility of the existence of a zinc heteroligand complex with 3,7,11,15-tetraazaporphine and fluoride ion with an oxidation state of Zn(III), unusual for the given element, is shown. Data on the structural parameters and multiplicity of the ground state of this complex are also presented.