Heptaphyrins: expanded porphyrins with seven heterocyclic rings

Expanded porphyrins containing seven pyrrole/heterocyclic rings linked in a cyclic fashion are termed heptaphyrins. The number of π-electrons in heptaphyrins depends on the number ofmeso carbon bridges used to link the heterocyclic rings, accordingly heptaphyrins with 28π-electrons and 30π-electrons are reported to date. Both condensation reactions of the appropriate precursors and acid-catalysed oxidative coupling reactions have been utilized to synthesise the heptaphyrins. The 30π heptaphyrins exhibit rich structural diversity where some of the heterocyclic rings in the macrocycle undergo a 180° ring flipping. An overview of the synthetic methods employed for the synthesis of heptaphyrins, their spectroscopic properties, structural behaviour and aromatic properties are highlighted in this paper

Core modified oxybenziporphyrins: new aromatic ligands for metalcarbon bond activation

Successful syntheses of two new aromatic core modified oxybenziporphyrins by a simple 3 + 1 methodology and the first aromatic core modified oxybenziporphyrin palladium complex are reported

Supramolecular assemblies of sulfur- and selenium- containing expanded porphyrins mediated through noncovalent interactions

Various supramolecular assemblies based on expanded porphyrins building blocks containing sulfur and/or selenium in the core, formed through multiple non-covalent hydrogen bonding interactions are highlighted. Specifically, modified expanded porphyrins such as 22 π sapphyrins, 26 π rubyrins, and 34 π octaphyrins self assemble in solid state through C-HO, C-HN, C-HS, C-HSe, C-Hπ, and C-HCl interactions to form dimeric, oligomeric, and three dimensional networks. Furthermore, the supramolecular networks promoted by trapped solvent molecules such as nitrobenzene and bound anions such as chloride or trifluoroacetate through noncovalent interactions will be discussed

Meso-mesityl dithia- and diselenarubyrins: existence of planar and inverted forms in solution

Syntheses, characterization and spectroscopic studies of meso-mesityl substituted rubyrins are reported. Specifically, it has been shown that these rubyrins behave differently from the meso-phenyl containing rubyrins in their structure. 1H NMR studies reveal the existence of both planar and inverted isomers in solution in different ratios both in the freebase and protonated forms

Modified corroles with one meso-free carbon: synthesis and characterization

Synthesis of mono meso-free modified corroles by a [3+1] methodology is reported

PINE: An Automation Tool to Extract and Visualize Protein-Centric Functional Networks.

Recent surges in mass spectrometry-based proteomics studies demand a concurrent rise in speedy and optimized data processing tools and pipelines. Although several stand-alone bioinformatics tools exist that provide protein-protein interaction (PPI) data, we developed Protein Interaction Network Extractor (PINE) as a fully automated, user-friendly, graphical user interface application for visualization and exploration of global proteome and post-translational modification (PTM) based networks. PINE also supports overlaying differential expression, statistical significance thresholds, and PTM sites on functionally enriched visualization networks to gain insights into proteome-wide regulatory mechanisms and PTM-mediated networks. To illustrate the relevance of the tool, we explore the total proteome and its PTM-associated relationships in two different nonalcoholic steatohepatitis (NASH) mouse models to demonstrate different context-specific case studies. The strength of this tool relies in its ability to (1) perform accurate protein identifier mapping to resolve ambiguity, (2) retrieve interaction data from multiple publicly available PPI databases, and (3) assimilate these complex networks into functionally enriched pathways, ontology categories, and terms. Ultimately, PINE can be used as an extremely powerful tool for novel hypothesis generation to understand underlying disease mechanisms

Protein arginine deiminase 2 (PAD2) modulates the polarization of THP-1 macrophages to the anti-inflammatory M2 phenotype

BACKGROUND: Macrophages are effector cells of the innate immune system that undergo phenotypical changes in response to organ injury and repair. These cells are most often classified as proinflammatory M1 and anti-inflammatory M2 macrophages. Protein arginine deiminase (PAD), which catalyses the irreversible conversion of protein-bound arginine into citrulline, is expressed in macrophages. However, the substrates of PAD and its role in immune cells remain unclear. This study aimed to investigate the role of PAD in THP-1 macrophage polarization to the M1 and M2 phenotypes and identify the citrullinated proteins and modified arginines that are associated with this biological switch using mass spectrometry. RESULTS: Our study showed that PAD2 and, to a lesser extent, PAD1 and PAD4 were predominantly expressed in M1 macrophages. We showed that inhibiting PAD expression with BB-Cl-amidine decreased macrophage polarization to the M1 phenotype (TNF-α, IL-6) and increased macrophage polarization to the M2 phenotype (MRC1, ALOX15). This process was mediated by the downregulation of proteins involved in the NF-κβ pathway. Silencing PAD2 confirmed the activation of M2 macrophages by increasing the antiviral innate immune response and interferon signalling. A total of 192 novel citrullination sites associated with inflammation, cell death and DNA/RNA processing pathways were identified in M1 and M2 macrophages. CONCLUSIONS: We showed that inhibiting PAD activity using a pharmacological inhibitor or silencing PAD2 with PAD2 siRNA shifted the activation of macrophages towards the M2 phenotype, which can be crucial for designing novel macrophage-mediated therapeutic strategies. We revealed a major citrullinated proteome and its rearrangement following macrophage polarization, which after further validation could lead to significant clinical benefits for the treatment of inflammation and autoimmune diseases. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12950-022-00317-8

Electronic interactions in <i>meso </i>ferrocenyl porphyrin and its metal derivatives

2191-2197Synthesis, characterization, spectroscopic and electrochemical studies on meso tetraferrocenyl porphyrin are reported. Substitution of ferrocenyl groups on the meso carbons affect the electronic structure of the porphyryn as well as the ferrocenyl moiety. This is reflected in the shift of electronic absorption band and redox potentials in the ferrocenyl containing porphyrin relative to the porphyrins without ferrocenyl group. Single crystal X-ray structure of freebase reveals an α,β,α,β orientation of the ferrocenyl groups relative to the mean plane of the porphyrin ring. Introduction of metal into the porphyrin ring does not alter the electronic structure of the metal as revealed by EPR spectrum for Cu2+ derivative