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Molecules (Basel, Switzerland) May 2024-Tetrahexylporphyrin was converted to its corresponding 7,8-dihydroxychlorin using an osmium tetroxide-mediated dihydroxylation strategy. Its diol moiety was shown to be...
-Tetrahexylporphyrin was converted to its corresponding 7,8-dihydroxychlorin using an osmium tetroxide-mediated dihydroxylation strategy. Its diol moiety was shown to be able to undergo a number of subsequent oxidation reactions to form a chlorin dione and porpholactone, the first -alkylporphyrin-based porphyrinoid containing a non-pyrrolic building block. Further, the diol chlorin was shown to be susceptible to dehydration, forming the porphyrin enol that is in equilibrium with its keto-chlorin form. The -hexylchlorin dione could be reduced and it underwent mono- and bis-methylation reactions using methyl-Grignard reagents, and trifluoromethylation using the Ruppert-Prakash reagent. The optical and spectroscopic properties of the products are discussed and contrasted to their corresponding -aryl derivatives (where known). This contribution establishes -tetrahexyl-7,8-dihydroxychlorins as a new and versatile class of chlorins that is susceptible to a broad range of conversions to generate functionalized chlorins and a pyrrole-modified chlorin analogue.
PubMed: 38731635
DOI: 10.3390/molecules29092144 -
Molecules (Basel, Switzerland) Apr 2024The one-pot synthesis of N-doped graphene quantum dots (GQDs), capped with a positively charged polyamine (trien), has been realized through a microwave-assisted...
The one-pot synthesis of N-doped graphene quantum dots (GQDs), capped with a positively charged polyamine (trien), has been realized through a microwave-assisted pyrolysis on solid L-glutamic acid and trien in equimolar amounts. The resulting positively charged nanoparticles are strongly emissive in aqueous solutions and are stable for months. The interaction with the anionic tetrakis(4-sulphonatophenyl)porphyrin (TPPS) has been investigated at neutral and mild acidic pH using a combination of UV/vis absorption spectroscopy together with static and time-resolved fluorescence emission. At pH = 7, the experimental evidence points to the formation of a supramolecular adduct mainly stabilized by electrostatic interactions. The fluorescence emission of the porphyrin is substantially quenched while GQDs remain still emissive. On decreasing the pH, protonation of TPPS leads to formation of porphyrin J-aggregates through the intermediacy of the charged quantum dots.
PubMed: 38731505
DOI: 10.3390/molecules29092015 -
Nature Communications May 2024Bleeding and thrombosis are known as common complications of polycythemia for a long time. However, the role of coagulation system in erythropoiesis is unclear. Here, we...
Bleeding and thrombosis are known as common complications of polycythemia for a long time. However, the role of coagulation system in erythropoiesis is unclear. Here, we discover that an anticoagulant protein tissue factor pathway inhibitor (TFPI) plays an essential role in erythropoiesis via the control of heme biosynthesis in central macrophages. TFPI levels are elevated in erythroblasts of human erythroblastic islands with JAK2 mutation and hypoxia condition. Erythroid lineage-specific knockout TFPI results in impaired erythropoiesis through decreasing ferrochelatase expression and heme biosynthesis in central macrophages. Mechanistically, the TFPI interacts with thrombomodulin to promote the downstream ERK1/2-GATA1 signaling pathway to induce heme biosynthesis in central macrophages. Furthermore, TFPI blockade impairs human erythropoiesis in vitro, and normalizes the erythroid compartment in mice with polycythemia. These results show that erythroblast-derived TFPI plays an important role in the regulation of erythropoiesis and reveal an interplay between erythroblasts and central macrophages.
Topics: Polycythemia; Erythroblasts; Erythropoiesis; Heme; Humans; Animals; Lipoproteins; Macrophages; Mice; GATA1 Transcription Factor; Janus Kinase 2; Thrombomodulin; Mice, Knockout; Ferrochelatase; Male; MAP Kinase Signaling System; Mice, Inbred C57BL; Female
PubMed: 38729948
DOI: 10.1038/s41467-024-48328-8 -
Ecotoxicology and Environmental Safety Jun 2024Cadmium contamination can lead to a decrease in crop yield and quality. However, Cd-tolerant rice can improve rice resistance genes, improve crop tolerance to heavy...
Cadmium contamination can lead to a decrease in crop yield and quality. However, Cd-tolerant rice can improve rice resistance genes, improve crop tolerance to heavy metals, and protect plants from oxidative damage. In this study, Japonica rice: Chunyou 987 and Indica rice: Chuanzhong you 3607 were used to reveal the molecular response mechanism of Cd-tolerant rice under cadmium concentration of 3 mg/kg through comparative experiments combined with physiology and proteomics. The results showed that compared with indica rice, japonica rice showed more robust resistance to Cd stress and effectively retained many Cd ions in roots. Moreover, it enhanced its enzymatic and non-enzymatic anti-oxidative stress mechanism, which increased the activities of catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) by 47.37%, 21.75%, and 55.42%, respectively. The contents of non-enzymatic antioxidant substances ascorbic acid (AsA), glutathione (GSH), cysteine (Cys), proline (PRO), anthocyanins (OPC), and flavonoids were increased by 25.32%, 42.67%, 21.43%, 50.81%, 33.23%, and 72.16%, respectively. Through proteomics analysis, it was found that in response to the damage caused by cadmium stress, Japonica rice makes Photosynthesis functional proteins (psbO and PetH), Photosynthesis antenna proteins (LHCA and ASCAB9), Carbon fixation functional proteins (PEPC and OsAld), Porphyrin metabolism functional proteins (OsRCCR1 and SE5), Glyoxylate and dicarboxylate The expression of metabolism functional proteins (CATC and GLO4.) and Glutathione metabolism functional proteins (APX8 and OsGSTU13) were significantly up-regulated, which stimulated the antioxidant stress mechanism and photosynthetic system, and constructed a robust energy supply system to ensure the normal metabolic activities of life. Strengthening the mechanisms of plant homeostasis. In summary, this study revealed the molecular mechanism of tolerance to Cd stress in japonica rice, and the results of this study will provide a possible way to improve Cd-resistant rice seedlings.
Topics: Oryza; Cadmium; Proteomics; Soil Pollutants; Oxidative Stress; Photosynthesis; Antioxidants; Plant Roots; Plant Proteins; Stress, Physiological; Superoxide Dismutase
PubMed: 38728942
DOI: 10.1016/j.ecoenv.2024.116413 -
Tailoring the efficiency of porphyrin molecular frameworks for the electroactivation of molecular N.Journal of Materials Chemistry. A May 2024The combination of compositional versatility and topological diversity for the integration of electroactive species into high-porosity molecular architectures is perhaps...
The combination of compositional versatility and topological diversity for the integration of electroactive species into high-porosity molecular architectures is perhaps one of the main appeals of metal-organic frameworks (MOFs) in the field of electrocatalysis. This premise has attracted much interest in recent years, and the results generated have also revealed one of the main limitations of molecular materials in this context: low stability under electrocatalytic conditions. Using zirconium MOFs as a starting point, in this work, we use this stability as a variable to discriminate between the most suitable electrocatalytic reaction and specific topologies within this family. Our results revealed that the PCN-224 family is particularly suitable for the electroreduction of molecular nitrogen for the formation of ammonia with faradaic efficiencies above 30% in the presence of Ni sites, an activity that improves most of the catalysts described. We also introduce the fluorination of porphyrin at the position as a good alternative to improve both the activity and stability of this material under electrocatalytic conditions.
PubMed: 38725524
DOI: 10.1039/d3ta07004b -
Chemical Science May 2024A Co-porphyrin complex (1) with an appended aza-crown ether for Lewis acid (LA) binding was synthesized and characterized. NMR spectroscopy and electrochemistry show...
A Co-porphyrin complex (1) with an appended aza-crown ether for Lewis acid (LA) binding was synthesized and characterized. NMR spectroscopy and electrochemistry show that cationic group I and II LAs (, Li, Na, K, Ca, Sr, and Ba) bind to the aza-crown ether group of 1. The binding constant for Li is comparable to that observed for a free aza-crown ether. LA binding causes an anodic shift in the Co/Co couple of between 10 and 40 mV and also impacts the Co/Co couple. The magnitude of the anodic shift of the Co/Co couple varies linearly with the strength of the LA as determined by the p of the corresponding metal-aqua complex, with dications giving larger shifts than monocations. The extent of the anodic shift of the Co/Co couple also increases as the ionic strength of the solution decreases. This is consistent with electric field effects being responsible for the changes in the redox properties of 1 upon LA binding and provides a novel method to tune the reduction potential. Density functional theory calculations indicate that the bound LA is 5.6 to 6.8 Å away from the Co ion, demonstrating that long-range electrostatic effects, which do not involve changes to the primary coordination sphere, are responsible for the variations in redox chemistry. Compound 1 was investigated as a CO reduction electrocatalyst and shows high activity but rapid decomposition.
PubMed: 38725508
DOI: 10.1039/d3sc06177a -
Chemical Science May 2024The understanding of electron transfer pathways and orbital interactions between analytes and adsorption sites in gas-sensitive studies, especially at the atomic level,...
The understanding of electron transfer pathways and orbital interactions between analytes and adsorption sites in gas-sensitive studies, especially at the atomic level, is currently limited. Herein, we have designed eight isoreticular catechol-metalloporphyrin scaffolds, FeTCP-M and InTCP-M (TCP = 5,10,15,20-tetrakis-catechol-porphyrin, M = Fe, Co, Ni and Zn) with adjustable charge transfer schemes in the coordination microenvironment and precise tuning of orbital interactions between analytes and adsorption sites, which can be used as models for exploring the influence of these factors on gas sensing. Our experimental findings indicate that the sensitivity and selectivity can be modulated using the type of metals in the metal-catechol chains (which regulate the electron transfer routes) and the metalloporphyrin rings (which fine-tune the orbital interactions between analytes and adsorption sites). Among the isostructures, InTCP-Co demonstrates the highest response and selectivity to NO under visible light irradiation, which could be attributed to the more favorable transfer pathway of charge carriers in the coordination microenvironment under visible light illumination, as well as the better electron spin state compatibility, higher orbital overlap and orbital symmetry matching between the N-2s2p hybrid orbital of NO and the Co-3d orbital of InTCP-Co.
PubMed: 38725503
DOI: 10.1039/d3sc06909e -
Photodiagnosis and Photodynamic Therapy Jun 2024Photodynamic therapy (PDT) is used for the treatment of centrally-located early lung cancers (CLELCs) and is recommended for tumors ≤ 1.0 cm in diameter. We previously...
BACKGROUND
Photodynamic therapy (PDT) is used for the treatment of centrally-located early lung cancers (CLELCs) and is recommended for tumors ≤ 1.0 cm in diameter. We previously reported that PDT using talaporfin sodium, second-generation photosensitizer, for tumors > 1.0 cm but ≤ 2.0 cm in diameter was able to achieve a therapeutic outcome comparable to that of tumors with a diameter of ≤ 1.0 cm. However, the effectiveness of PDT using talaporfin sodium for tumors > 2.0 cm in diameter remains unclear. We conducted a retrospective analysis of cases in which PDT was performed for flat-type CLELCs with tumor diameters of > 2.0 cm.
METHODS
We retrospectively analyzed seven cases (eight lesions) with tumor diameters > 2.0 cm and no evidence of extracartilaginous invasion or lymph node metastasis.
RESULTS
All the patients underwent multiple PDT sessions. The PDT treatment results over the study period were partial response in one case (14.3 %), stable disease (SD) in three cases (42.9 %), and progressive disease (PD) in three cases (42.9 %). At the time of writing this report, five of seven cases (71.4 %) are still undergoing treatment. The duration of SD-the time from the start of treatment until the criteria for PD were met (SD or better maintained)-ranged from 7 to 52 months (mean, 25.3 months).
CONCLUSIONS
"Maintenance PDT" for CLELCs > 2.0 cm in diameter has the potential to inhibit tumor progression in the long term while maintaining quality of life, rather than simply aiming only for a quick radical cure.
Topics: Humans; Photochemotherapy; Lung Neoplasms; Photosensitizing Agents; Male; Aged; Female; Retrospective Studies; Middle Aged; Porphyrins; Aged, 80 and over; Treatment Outcome
PubMed: 38723757
DOI: 10.1016/j.pdpdt.2024.104200 -
Journal of Photochemistry and... Jul 2024Emerging antibiotic resistance among bacterial pathogens has forced an urgent need for alternative non-antibiotic strategies development that could combat drug...
INTRODUCTION
Emerging antibiotic resistance among bacterial pathogens has forced an urgent need for alternative non-antibiotic strategies development that could combat drug resistant-associated infections. Suppression of virulence of ESKAPE pathogens' by targeting multiple virulence traits provides a promising approach.
OBJECTIVES
Here we propose an iron-blocking antibacterial therapy based on a cationic heme-mimetic gallium porphyrin (GaCHP), which antibacterial efficacy could be further enhanced by photodynamic inactivation.
METHODS
We used gallium heme mimetic porphyrin (GaCHP) excited with light to significantly reduce microbial viability and suppress both the expression and biological activity of several virulence traits of both Gram-positive and Gram-negative ESKAPE representatives, i.e., S. aureus and P. aeruginosa. Moreover, further improvement of the proposed strategy by combining it with routinely used antimicrobials to resensitize the microbes to antibiotics and provide enhanced bactericidal efficacy was investigated.
RESULTS
The proposed strategy led to substantial inactivation of critical priority pathogens and has been evidenced to suppress the expression and biological activity of multiple virulence factors in S. aureus and P. aeruginosa. Finally, the combination of GaCHP phototreatment and antibiotics resulted in promising strategy to overcome antibiotic resistance of the studied microbes and to enhance disinfection of drug resistant pathogens.
CONCLUSION
Lastly, considering high safety aspects of the proposed treatment toward host cells, i.e., lack of mutagenicity, no dark toxicity and mild phototoxicity, we describe an efficient alternative that simultaneously suppresses the functionality of multiple virulence factors in ESKAPE pathogens.
Topics: Photosensitizing Agents; Gallium; Porphyrins; Pseudomonas aeruginosa; Staphylococcus aureus; Heme; Anti-Bacterial Agents; Virulence; Microbial Sensitivity Tests; Light; Drug Resistance, Bacterial
PubMed: 38723545
DOI: 10.1016/j.jphotobiol.2024.112928 -
Journal of the American Chemical Society May 2024Construction of robust heterogeneous catalysts with atomic precision is a long-sought pursuit in the catalysis field due to its fundamental significance in taming...
Construction of robust heterogeneous catalysts with atomic precision is a long-sought pursuit in the catalysis field due to its fundamental significance in taming chemical transformations. Herein, we present the synthesis of a single-crystalline pyrazolate metal-organic framework (MOF) named PCN-300, bearing a lamellar structure with two distinct Cu centers and one-dimensional (1D) open channels when stacked. PCN-300 exhibits exceptional stability in aqueous solutions across a broad pH range from 1 to 14. In contrast, its monomeric counterpart assembled through hydrogen bonding displays limited stability, emphasizing the role of Cu-pyrazolate coordination bonds in framework robustness. Remarkably, the synergy of the 1D open channels, excellent stability, and the active Cu-porphyrin sites endows PCN-300 with outstanding catalytic activity in the cross dehydrogenative coupling reaction to form the C-O bond without the "compulsory" -position directing groups (yields up to 96%), outperforming homogeneous Cu-porphyrin catalysts. Moreover, PCN-300 exhibits superior recyclability and compatibility with various phenol substrates. Control experiments reveal the synergy between the Cu-porphyrin center and framework in PCN-300 and computations unveil the free radical pathway of the reaction. This study highlights the power of robust pyrazolate MOFs in directly activating C-H bonds and catalyzing challenging chemical transformations in an environmentally friendly manner.
PubMed: 38723205
DOI: 10.1021/jacs.4c03038