Catalytic and Base-free Suzuki-type α-Arylation of Cyclic 1,3-Dicarbonyls via a Cyclic Iodonium Ylide Strategy.

To date, it remains challenging to achieve a general and catalytic α-arylation of cyclic 1,3-dicarbonyls, particularly ubiquitous heteroaromatic ones. In most cases, the preparation of their medically significant arylated derivatives requires multistep synthetic sequences. Herein, we introduce a new, convenient strategy involving the conversion of cyclic 1,3-dicarbonyls to cyclic iodonium ylides (CIYs), followed by rhodium-catalyzed α-arylation with arylboronic reagents via carbene coupling. This approach is mild, operationally simple, base-free, biocompatible, and exhibits broad substrate scope (>100 examples), especially with respect to various heteroaromatic 1,3-dicarbonyls and ortho-substituted or base-sensitive arylboronic acids. Importantly, owing to the excellent compatibility with various arylboronic acids or boronate esters (ArBpin, ArBneop, or ArBF3K), this method allows the late-stage installation of heterocyclic 1,3-dicarbonyl motifs in highly complex settings. The utility of this transformation is further demonstrated through significantly simplifying the synthesis of several bioactive molecules and natural products.

Noncovalent composites of meso-substituted A2B2-porphyrins and carbon nanotubes for enhanced electrocatalytic oxygen reduction.

Exploring highly active oxygen reduction electrocatalysts with low precious metals content is imperative but remains a considerable challenge. Herein, a series of heterobimetallic multi-walled carbon nanotubes (MWCNTs) electrocatalysts based on metal complexes are presented. These electrocatalysts feature diverse transition metals (M=Mn, Fe, Co, Ni) 5,15-bromophenyl-10, 20-methoxyphenyl porphyrin (MBMP) and tetrakis(triphenylphosphine)palladium (0) (Pd[P(Ph3)4]) anchored non-covalently on its surface. The resulting NiBMP-based MWCNTs with Pd[P(Ph3)4] (PdNiN4/MWCNTs) display outstanding electrocatalytic oxygen reduction activity (onset potential, 0.941 V; half wave potential, 0.830 V) and robust long-term durability in alkaline electrolyte. While in neutral condition, the MnBMP-based MWCNTs with Pd[P(Ph3)4] (PdMnN4/MWCNTs) are the most active heterobimetallic ORR catalyst and produce ultra-low concentration hydrogen peroxide (H2O2yield, 1.2%-1.3%). Synergistically tuning the ORR electrocatalytic activity and electron transfer pathway is achieved by the formation of NiBMP/MnBMP-Pd[P(Ph3)4] active sites. This work indicates such metalloporphyrin-Pd[P(Ph3)4] active sites on MWCNTs have significantly positive influence on electrocatalytic ORR systems and provides facile and mild strategy for designing highly efficient ORR electrocatalysts with ultra-low loading precious metal.

Manganese corrole catalyzed selective oxidation of styrene to benzaldehyde: sodium nitrite functions as an oxidant and cocatalyst.

Catalytic oxidation using manganese corrole is a hot topic of contemporary porphyrin chemistry, in which PhIO, TBHP, PhI(OAc)2, KHSO5 and m-CPBA are usually used as oxidants. This article reports the first selective oxidation of styrene to benzaldehyde using a manganese(III) corrole catalyst and sodium nitrite (NaNO2) as oxidant and cocatalyst at room temperature. The yield was 158.1% in air and 96.5% under a nitrogen atmosphere, showing oxygen might be involved in the reaction and that NaNO2 is an oxygen source and cocatalyst in the system. The peripheral electron-withdrawing substituents of the manganese corrole were favorable to the catalytic reaction. Radical inhibition and H218O experiments proved that the catalytic reaction was a free radical and hydrolysis-involved reaction.

Photodynamic Antitumor Activity of 5,15-Bis(perfluorophenyl)-10-(4-carboxyphenyl)corrole and its Gallium(III) and Phosphorus(V) Complexes.

This work reports the preparation and characterization of an A2 B corrole 5,15-bis(perfluorophenyl)-10-(4-carboxyphenyl)corrole and its gallium(III) and phosphorus(V) complexes. Their in-vitro photodynamic anticancer activities against A549, MDA-MB-231, B16, HepG2, and Hela cell lines were also investigated. Among three compounds, phosphorus(V) complexexhibits the best photostability, highest fluorescence quantum yields (ΦF =0.138), and the highest singlet-oxygen quantum yields (ΦΔ =0.87). Also, the phosphorus(V) complex exhibits the best photodynamic antitumor activity against MDA-MB-231 cells with a low IC50 (0.08 µM) upon light irradiation at 625±2 nm, which is much lower than commercial PDT drug Temoporfin (0.1 µM) at the same conditions. The cellular localization assay confirmed that the phosphorus(V) complexis mainly distributed in the cytoplasm and have a good ability to produce reactive oxygen species (ROS) under light illumination, which would further cause oxidative damage to tumor cells and finally result in the apoptosis. After PDT treatment, phosphorus(V) complex may cause tumor cell arrest at the G2/M stage. The preliminary results showed phosphorus(V) corrole complex is a good candidate for photodynamic therapy (PDT) of tumors.

SOCS1 Regulates the Immunomodulatory Roles of MSCs on B Cells.

BACKGROUND AND OBJECTIVES: The effective use of MSCs for the treatment of some B cell-mediated immune diseases is quite limited. The main reason is that the immunomodulatory effects of mesenchymal stem cells (MSCs) on B cells are unclear, and their underlying mechanisms have not been fully explored. METHODS AND RESULTS: By co-culturing B cells with MSCs without (MSC/CTLsh) or with suppressor of cytokine signaling 1 (SOCS1) knockdown (MSC/SOCS1sh), we found that MSCs inhibited B cell proliferation, activation and terminal differentiation. Remarkably, the highest inhibition of B cell proliferation was observed in MSC/SOCS1sh co-culture. Besides, MSC/SOCS1sh reversed the inhibitory effect of MSCs in the last stage of B cell differentiation. However, MSC/SOCS1sh had no effect on inhibiting B cell activation by MSCs. We also showed that IgA+ B cell production was significantly higher in MSC/SOCS1sh than in MSC/CTLsh, although no difference was observed when both MSCs co-cultures were compared to isolated B cells. In addition, MSCs increased PGE2 production after TNF-α/IFN-γ stimulation, with the highest increase observed in MSC/SOCS1sh co-culture. CONCLUSIONS: Our results highlighted the role of SOCS1 as an important new mediator in the regulation of B cell function by MSCs. Therefore, these data may help to develop new treatments for B cell-mediated immune diseases.

SOCS1 Regulates the Immunomodulatory Roles of MSCs on B Cells

Background and Objectives@#The effective use of MSCs for the treatment of some B cell-mediated immune diseases is quite limited. The main reason is that the immunomodulatory effects of mesenchymal stem cells (MSCs) on B cells are unclear, and their underlying mechanisms have not been fully explored. @*Methods@#and Results: By co-culturing B cells with MSCs without (MSC/CTLsh) or with suppressor of cytokine signaling 1 (SOCS1) knockdown (MSC/SOCS1sh), we found that MSCs inhibited B cell proliferation, activation and terminal differentiation. Remarkably, the highest inhibition of B cell proliferation was observed in MSC/SOCS1sh co-culture. Besides, MSC/SOCS1sh reversed the inhibitory effect of MSCs in the last stage of B cell differentiation. However, MSC/SOCS1sh had no effect on inhibiting B cell activation by MSCs. We also showed that IgA+ B cell production was significantly higher in MSC/SOCS1sh than in MSC/CTLsh, although no difference was observed when both MSCs co-cultures were compared to isolated B cells. In addition, MSCs increased PGE2 production after TNF-α/IFN-γ stimulation, with the highest increase observed in MSC/SOCS1sh co-culture. @*Conclusions@#Our results highlighted the role of SOCS1 as an important new mediator in the regulation of B cell function by MSCs. Therefore, these data may help to develop new treatments for B cell-mediated immune diseases.

The photocytotoxicity effect of cationic sulfonated corrole towards lung cancer cells: in vitro and in vivo study.

Corrole is a kind of new and promising photosensitizer (PS) in cancer photodynamic therapy (PDT). However, the protein molecular mechanism of PDT activity for corrole under light irradiation is still not clear. In this paper, water-soluble cationic sulfonated corrole (1) and its metal complexes (1-Fe, 1-Mn, and 1-Cu) were prepared, and the photodynamic anti-cancer activity against various tumor cells was investigated by MTT assay. The potential molecular mechanism of PDT activity was elucidated by fluorescence microscope, flow cytometry, molecular docking, and western blotting analysis. Besides, the potential PDT anti-tumor effect of 1 in vivo was assessed in human tumor xenografts in mice. Quantitative analysis revealed that 1's phototoxicity triggered a significant generation of reactive oxygen species, causing disruption of mitochondrial membrane potential. The results of western blotting (WB) assay shown in 1's phototoxicity could induce cell apoptosis via ROS-mediated mitochondrial caspase apoptosis pathway, in which SIRT1 protein degradation played a key role. PTD activity in vivo shown in 1 could significantly reduce the growth of A549 xenografted tumor, without obvious loss of mice body weight. We clearly found that cationic sulfonated corrole is a potential candidate of PS in vitro and in vivo. The phototoxicity of 1 could induce A549 cell apoptosis by inducing ROS production increase, further to activate the mitochondrial apoptosis pathway. We concluded that SIRT1 protein is a more appropriate target in this progress.

Puerarin prevents vascular endothelial injury through suppression of NF-κB activation in LPS-challenged human umbilical vein endothelial cells.

OBJECTIVE: In the present study, we aimed to explore the effects of puerarin on vascular endothelial cell injury induced by lipopolysaccharide (LPS) and its underlying mechanisms. METHODS: The cell viability and morphological changes were assessed using the cell counting kit-8 (CCK-8) assay and 4´,6-diamidino-2-phenylindole (DAPI) staining, respectively. The levels of tumor necrosis factor-alpha (TNF-α), interleukin-1ß (IL-1ß), monocyte/macrophage chemotactic protein-1 (MCP-1), IL-8, intercellular cell adhesion molecule-1 (ICAM-1), thrombomodulin (TM) and plasminogen activator inhibitor-1 (PAI-1) in cell culture supernatant were determined by the enzyme-linked immunosorbent assay (ELISA). The neutrophils adhesion to endothelial cells were examined by myeloperoxidase activity assay. The nuclear translocation of nuclear factor-κB p65 (NF-κB p65) was assessed by immunofluorescence analysis. RESULTS: Compared with the control group, LPS challenge significantly injured human umbilical vein endothelial cells (HUVECs) and increased the levels of TNF-α, IL-1ß, MCP-1, IL-8, ICAM-1, TM and PAI-1 in the cell culture supernatants. The neutrophils adhesion to endothelial cells were significantly increased in LPS-challenged HUVECs. Moreover, LPS challenge increased the nuclear translocation of NF-κB p65. However, puerarin pre-treatment attenuated the vascular endothelial injury and reduced the levels of TNF-α, IL-1ß, MCP-1, IL-8, ICAM-1, TM and PAI-1 in cell supernatants of LPS-challenged HUVECs. In addition, the neutrophils adhesion to HUVECs induced by LPS were also decreased by puerarin pre-treatment. Furthermore, puerarin pre-treatment reduced the nuclear translocation of NF-κB p65 elicited by LPS. CONCLUSIONS: Puerarin prevented LPS-induced vascular endothelial injury, the mechanism of which might be related to the suppression of NF-κB activation and subsequently altered levels of inflammatory factors and coagulation-related factors.

Green tea polyphenols alter lipid metabolism in the livers of broiler chickens through increased phosphorylation of AMP-activated protein kinase.

Our previous results showed that green tea polyphenols (GTPs) significantly altered the expression of lipid-metabolizing genes in the liver of chickens. However, the underlying mechanism was not elucidated. In this study, we further characterized how GTPs influence AMP-activated protein kinase (AMPK) in the regulation of hepatic fat metabolism. Thirty-six male chickens were fed GTPs at a daily dose of 0, 80 or 160 mg/kg of body weight for 4 weeks. The results demonstrated that oral administration of GTPs significantly reduced hepatic lipid content and abdominal fat mass, enhanced the phosphorylation levels of AMPKα and ACACA, and altered the mRNA levels and enzymatic activities of lipid-metabolizing enzymes in the liver. These results suggested that the activation of AMPK is a potential mechanism by which GTPs regulate hepatic lipid metabolism in such a way that lipid synthesis is reduced and fat oxidation is stimulated.

[Analysis on mutations of GJB2 gene in Chinese population].

OBJECTIVE: To determine the prevalence and types of GJB2 mutations and to investigate the genetic mechanism in Chinese autosomal recessive deafness. METHODS: The subjects were four Chinese pedigrees (39 individuals) and 50 normal adults. GJB2 was amplified by PCR. The products were digested with restriction enzyme Apa I, then sequenced. RESULTS: Homozygous deletion C at position 232-235 of GJB2 (235delC),which resulted in frameshift mutation, was found in four affected individuals of two pedigrees; the compound heterozygous deletions (235delC/232G to A) were found in two affected individuals in one pedigree. One carrier with 235delC was found in normal controls (1% allele). Two kinds of polymorphisms 79G to A(V27I) and 3 41A to G(E114G) were found in both affected and normal controls. The frequencies of allele for 79G to A and 341A to G in normal controls were 30%, 21%, respectively. CONCLUSION: 235delC mutation of GJB2 was related with Chinese autosomal recessive deafness, and the 232G to A(Ala78Thr) missense mutation was found to be a novel mutation.

Analysis on mutations of GJB2 gene in Chinese population / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To determine the prevalence and types of GJB2 mutations and to investigate the genetic mechanism in Chinese autosomal recessive deafness.</p><p><b>METHODS</b>The subjects were four Chinese pedigrees (39 individuals) and 50 normal adults. GJB2 was amplified by PCR. The products were digested with restriction enzyme Apa I, then sequenced.</p><p><b>RESULTS</b>Homozygous deletion C at position 232-235 of GJB2 (235delC),which resulted in frameshift mutation, was found in four affected individuals of two pedigrees; the compound heterozygous deletions (235delC/232G to A) were found in two affected individuals in one pedigree. One carrier with 235delC was found in normal controls (1% allele). Two kinds of polymorphisms 79G to A(V27I) and 3 41A to G(E114G) were found in both affected and normal controls. The frequencies of allele for 79G to A and 341A to G in normal controls were 30%, 21%, respectively.</p><p><b>CONCLUSION</b>235delC mutation of GJB2 was related with Chinese autosomal recessive deafness, and the 232G to A(Ala78Thr) missense mutation was found to be a novel mutation.</p>