Irena Saltsman

The First Direct Synthesis of Corroles from Pyrrole

The solvent-free, catalyst-free condensation of pyrrole and aldehydes provides an extremely facile synthetic pathway to novel corroles [Eq. (1); Ar=C6 F5 , 2,6-F2 C6 H3 , 2,6-Cl2 C6 H3 ]. The product containing pentafluorophenyl groups is an excellent precursor of other derivatives, including an ionic, water-soluble corrole.

Erste direkte Synthese von Corrolen aus Pyrrol

Die losungsmittel- und katalysatorfreie Kondensation von Pyrrol und Aldehyden bietet einen auserst einfachen Zugang zu neuartigen Corrolen [Gl. (1); Ar = C6F5, 2,6-F2C6H3, 2,6-Cl2C6H3]. Das Pentafluorphenyl-substituierte Produkt (Ar = C6F5) ist eine exzellente Vorstufe fur andere Derivate, einschlieslich eines ionischen, wasserloslichen Corrols.

Metallocorroles as cytoprotective agents against oxidative and nitrative stress in cellular models of neurodegeneration

J. Neurochem. (2010) 113, 363–373.

Differential Cytostatic and Cytotoxic Action of Metallocorroles against Human Cancer Cells: Potential Platforms for Anticancer Drug Development

A gallium(III)-substituted amphiphilic corrole noncovalently associated with a targeting protein was previously found by us to confer promising cytotoxic and antitumor activities against a breast cancer cell line and a mouse xenograft breast cancer model. To further explore potential anticancer applications, the cytostatic and cytotoxic properties of six nontargeted metallocorroles were evaluated against seven human cancer cell lines. Results indicated that toxicity toward human cancer cells depended on the metal ion as well as corrole functional group substitution. Ga(III)-substituted metallocorrole 1-Ga inhibited proliferation of breast (MDA-MB-231), melanoma (SK-MEL-28), and ovarian (OVCAR-3) cancer cells primarily by arrest of DNA replication, whereas 2-Mn displayed both cytostatic and cytotoxic properties. Confocal microscopy revealed extensive uptake of 1-Ga into the cytoplasm of melanoma and ovarian cancer cells, while prostate cancer cells (DU-145) displayed extensive nuclear localization. The localization of 1-Ga to the nucleus in DU-145 cells was exploited to achieve a 3-fold enhancement in the IC(50) of doxorubicin upon coadministration. Time-course studies showed that over 90% of melanoma cells incubated with 30 μM 1-Ga internalized metallocorrole after 15 min. Cellular uptake of 1-Ga and 1-Al was fastest and most efficient in melanoma, followed by prostate and ovarian cancer cells. Cell cycle analyses revealed that bis-sulfonated corroles containing Al(III), Ga(III), and Mn(III) induced late M phase arrest in several different cancer cell lines, a feature that could be developed for potential therapeutic benefit.

Photodynamic inactivation of mold fungi spores by newly developed charged corroles

The photodynamic effect, originally used in photodynamic therapy (PDT) for the treatment of different diseases, e.g. of cancer, has recently been introduced for the inactivation of bacteria. Mold fungi, which provoke health problems like allergies and diseases of the respiratory tract, are even more resistant and their biology is also very different. This study presents the development of four new photosensitizers, which, in combination with low doses of white light, inhibit the germination of mold fungi spores. Two of them even cause lethal damage to the conidia (spores) which are responsible for the spreading of mold fungi. The photoactivity of the newly synthesized corroles was obtained by their application on three different mold fungi: Aspergillus niger, Cladosporium cladosporoides, and Penicillium purpurgenum. To distinguish between inactivation of germination and permanent damage, the fungi were first incubated under illumination for examination of photosensitizer-induced growth inhibition and then left in darkness to test the survival of the conidia. None of the compounds displayed dark toxicity, but all of them attenuated or prevented germination when exposed to light, and the positively charged complexes induced a complete damage of the conidia.

One-step conversions of a simple corrole into chiral and amphiphilic derivatives

Abstract The reactions of phosgene with 5,10,15-tris(pentafluorophenyl)corrole and its gallium(III) complex lead to a novel chiral macrocycle and an amphiphilic corrole, respectively. Both types of molecules were fully characterized by spectroscopy and X-ray crystallography.

The first metal chelation by a neutral porphyrin analogue

The preparation and spectroscopic characterization of O2TTP—a modified porphyrin in which the two NH groups are replaced by oxygen atoms—and its dihalonickel(II) complexes lead to the conclusion that 21,23-dioxaporphyrins are exceptionally well suited for metal complexation and for stabilization of divalent nickel in paramagnetic pseudo-octahedral geometries.

Inhibition of green algae growth by corrole-based photosensitizers.

This study was performed to examine the potential of photodynamic inactivation for growth inhibition of green algae through generation of singlet oxygen.

Iron complexes of tris(4-nitrophenyl)corrole, with emphasis on the (nitrosyl)iron complex

The iron complexes of 5,10,15-tris(4-nitrophenyl)corrole have been prepared and characterized by various spectroscopic techniques. The (nitrosyl)iron complex is diamagnetic and its X-ray structure reveals an almost perfectly linear Fe–N–O bond. EPR spectroscopy in conjunction with 15N labelling were used to deduce the redox centre of the one-electron reduction and oxidation products of the (nitrosyl)iron corrole.

Time-Resolved Electron Paramagnetic Resonance and Phosphorescence Studies of the Lowest Excited Triplet States of Rh(III) Corrole Complexes

The lowest excited triplet (T(1)) ππ* states of gallium (Ga) and various rhodium (Rh) 5,10,15-trispentafluorophenyl corroles (Cors) were studied in the liquid crystal (LC) E-7 and in rigid glasses by time-resolved electron paramagnetic resonance (TR-EPR) spectroscopy. The triplet sublevel energies were experimentally determined by the alignment of the molecules in the LC and by magnetophotoselection in the glass. The sublevel scheme of GaCor was determined by calculating the zero field splitting (ZFS) parameters. Axial ligand effects and quantum chemical calculations were used for the sublevel assignment of RhCors. The anisotropic EPR parameters were used to determine the important higher excited states and the magnitudes of their spin-orbit coupling (SOC) contributions were evaluated. On the basis of these results and analyses, the EPR parameters and triplet lifetime were discussed for each RhCor complex.