Search

A limited delivery of oxygen and metabolic substrate to the heart caused by myocardial infarction (MI) impairs the cardiac function, and often results in heart failure. Here, we identified a circRNA (circ-SNRK) from SNRK (sucrose nonfermenting 1-related kinase, which can increase the cardiac mitochondrial efficiency) in cardiomyocytes (CMs). Circ-SNRK can sponge the miR-33 and in turn improved the ATP synthesis via SNRK, proving the existence of circ-SNRK - miR-33 - SNRK axis. Furthermore, we found that protein NOVA1 (NOVA alternative splicing regulator 1) could accelerate the circ-SNRK formation; a cleaved peptide (~55 kDa) from SNRK enters the nucleus and blocks the cyclization of circ-SNRK via binding to NOVA1. The aforementioned negative feedback of SNRK to circ-SNRK limited the SNRK at a proper level, and inhibited the protective role of circ-SNRK in ischemic heart. In addition, our in vivo experiment indicated that the overexpression of exogenic circ-SNRK could break this loop and improves the cardiac function post-MI in rats. Together, our results demonstrated that the negative loop of circ-SNRK with SNRK regulates the energy metabolism in CMs, thus might be a potential therapeutic target for heart failure.

In this study, two homogeneous polysaccharides (PFC-1 and PFC-2) having anti-atherosclerotic activity were isolated from Fructus Corni. PFC-1 and PFC-2 were 1,6-α-glucans with the molecular weight of 4.4 kDa and 82.0 kDa, respectively. In the in vitro experiments, PFC-1 and PFC-2 showed significant inhibitory effects on the cholesterol accumulation in RAW264.7 macrophages induced by oxidized low-density lipoproteins (ox-LDL), and the inhibitory rate of PFC-2 was 81.62%. Apolipoprotein E-deficient (ApoE−/−) mice fed high-fat diet (HFD) were used to evaluate the anti-atherosclerotic effects of PFC-2 in vivo. The aortic root lipid area decreased by 55.01% in the PFC-2-administered group as compared to the model group. PFC-2 decreased the levels of serum low-density lipoprotein cholesterol, total cholesterol, triglycerides, and malondialdehyde, increased the superoxide dismutase activity, and reduced the contents of lipid and macrophages in the aortic sinus plaque in ApoE−/− mice fed with HFD. Furthermore, PFC-2 markedly inhibited the expression of type A1 scavenger receptor (SR-A1) and cluster of differentiation 36 (CD36) in ox-LDL-treated macrophages. Taken together, 1,6-α-glucans from Fructus Corni showed significant anti-atherogenic effect, and the mechanism is related to enhanced antioxidant activity of the ApoE−/− mice and down-regulated the expression of SR-A1 and CD36 proteins in macrophages.

NK-lysins, a type of broad-spectrum antimicrobial peptide (AMP), act as an essential effector of innate defense against microbial attack in higher vertebrates and so in fish. The present study delineates the structural and functional characterization of NK-lysin from yellow catfish (Pelteobagrus fulvidrac) (Pelteobagrus fulvidraco). PfNK-lysin encodes a 153-residue peptide, which displays the hallmark features of other known NK-lysins with the ordered array of six well-conserved cysteine residues and five-exon/four-intron structure. It was found to be ubiquitous in tissues, being detected most abundantly in gill and head kidney. In vivo exposure to stimuli (LPS, PolyI:C, and Edwardsiella ictaluri) induced PfNK-lysin expression in head kidney and spleen. Synthetic PfNK-lysin-derived peptide exhibited in vitro bactericidal potency against both Gram-positive and Gram-negative bacteria, with the highest inhibitory effect on pathogen Edwardsiella ictaluri. Fluorescence microscopy and scanning electron microscopy further confirmed its capacity to cause damage to the bacterial plasma membrane. Taken together, these data suggest that PfNK-lysin might participate in antimicrobial defense of yellow catfish by membrane-disruptive action.

Alginate, the most abundant polysaccharides of brown algae, consists of various proportions of uronic acid epimers α-L-guluronic acid (G) and β-D-mannuronic acid (M). Alginate oligosaccharides (AOs), the degradation products of alginates, exhibit excellent bioactivities and a great potential for broad applications in pharmaceutical fields. Alginate lyases can degrade alginate to functional AOs with unsaturated bonds or monosaccharides, which can facilitate the biorefinery of brown algae. On account of the increasing applications of AOs and biorefinery of brown algae, there is a scientific need to explore the important aspects of alginate lyase, such as catalytic mechanism, structure, and property. This review covers fundamental aspects and recent developments in basic information, structural characteristics, the structure–substrate specificity or catalytic efficiency relationship, property, molecular modification, and applications. To meet the needs of biorefinery systems of a broad array of biochemical products, alginate lyases with special properties, such as salt-activated, wide pH adaptation range, and cold adaptation are outlined. Withal, various challenges in alginate lyase research are traced out, and future directions, specifically on the molecular biology part of alginate lyases, are delineated to further widen the horizon of these exceptional alginate lyases.

Rationale: βARs (β-adrenergic receptors) are prototypical GPCRs (G protein–coupled receptors) that play a pivotal role in sympathetic regulation. In heart cells, β 1 AR signaling mediates a global response, including both l -type Ca 2+ channels in the sarcolemma/T tubules and RyRs (ryanodine receptors) in the SR (sarcoplasmic reticulum). In contrast, β 2 AR mediates local signaling with little effect on the function of SR proteins. Objective: To investigate the signaling relationship between β 1 ARs and β 2 ARs. Method and Results: Using whole-cell patch-clamp analyses combined with confocal Ca 2+ imaging, we found that the activation of compartmentalized β 2 AR signaling was able to convert the β 1 AR signaling from global to local mode, preventing β 1 ARs from phosphorylating RyRs that were only nanometers away from sarcolemma/T tubules. This offside compartmentalization was eliminated by selective inhibition of β 2 AR, GRK2 (GPCR kinase-2), βarr1 (β-arrestin-1), and phosphodiesterase-4. A knockin rat model harboring mutations of the last 3 serine residues of the β 1 AR C terminus, a component of the putative βarr1 binding site and GRK2 phosphorylation site, eliminated the offside compartmentalization conferred by β 2 AR activation. Conclusions: β 2 AR stimulation compartmentalizes β 1 AR signaling into nanoscale local domains in a phosphodiesterase-4–dependent manner by targeting the C terminus of β 1 ARs. This finding reveals a fundamental negative feed-forward mechanism that serves to avoid the cytotoxicity of circulating catecholamine and to sharpen the transient β 1 AR response of sympathetic excitation.

Rationale: Heat shock protein 9 (HSP90) are a family of the most highly expressed cellular proteins and attractive drug targets against cancer, neurodegeneration diseases, etc. HSP90 proteins have also been suggested to be linked to lipid metabolism. However, the specific function of HSP90 paralogs, as well as the underlying molecular cascades remains largely unknown. This study aims to unravel the paralog-specific role of HSP90 in lipid metabolism and try to discover paralog-specific HSP90 inhibitors. Methods: In non-alcohol fatty liver disease (NAFLD) patients, as well as in diet induced obese (DIO) mice, expression of HSP90 paralogs were analyzed by immunohistochemistry and western blot. In hepatocytes and in DIO mice, HSP90 proteins were knockdown by siRNAs/shRNAs, metabolic parameters, as well as downstream signaling were then investigated. By virtue screening, corylin was found to bind specifically to HSP90β. Using photo-affinity labeling and mass spectrum, corylin binding proteins were identified. After oral administration of corylin, its lipid lowering effects in different metabolic disease mice models were evaluated. Results: We showed that hepatic HSP90β, rather than HSP90α, was overexpressed in NAFLD patients and obese mice. Hepatic HSP90β was also clinical relevant to serum lipid level. Depletion of HSP90β promoted mature sterol regulatory element-binding proteins (mSREBPs) degradation through Akt-GSK3β-FBW7 pathway, thereby dramatically decreased the content of neutral lipids and cholesterol. We discovered an HSP90β-selective inhibitor (corylin) that only bound to its middle domain. We found that corylin treatment partially suppressed Akt activity only at Thr308 site and specifically promoted mSREBPs ubiquitination and proteasomal degradation. Corylin treatment significantly reduced lipid content in both liver cell lines and human primary hepatocytes. In animal studies, we showed that corylin ameliorated obesity-induced fatty liver disease, type 2 diabetes and atherosclerosis. Principle conclusions: HSP90β plays a parolog-specific role in regulating lipid homeostasis. Compound that selectively inhibits HSP90β could be useful in the clinic for the treatment for metabolic diseases.

A Gram-stain-negative, wheat, rod-shaped, motile, non-spore forming, and aerobic bacterium, designated as strain PIT, was isolated from saline silt samples collected in saltern in Yantai, Shandong, China, and subjected to a polyphasic taxonomic study. The 16S rRNA gene sequence analysis revealed a clear affiliation of strain PIT with the genus Kangiella. Strain PIT showed the closest phylogenetic relationship with Kangiella taiwanensis KT1T with the highest 16S rRNA gene sequence similarity of 98.3%. The genome size of the strain PIT was 2809662 bp consisting of 2653 genes which include 39 tRNAs genes, 2 sRNA genes and 4 rRNA genes. The major cellular fatty acids of strain PIT were identified as iso-C15:0, iso-C11:0, iso-C11:0 3-OH and Summed Feature 9 (iso-C17:1ω9c), and the major respiratory isoprenoid quinone was Q8. The major polar lipids were diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), phosphatidylmonomethylethanolamine (PME) and phosphatidylinositol (PI). The G+C content of the genomic DNA was 45.8 mol%. The Average Amino Acid identity (AAI) value between strain PIT and Kangiella sediminilitoris was 83.9%. The Average Nucleotide Identity (ANI) values between strain PIT and Kangiella sediminilitoris, Kangiella aquimarina and Kangiella taiwanensis were 76.9%, 71.0% and 74.6%, respectively. The digital DNA-DNA Hybridization (dDDH) values between strain PIT and Kangiella sediminilitoris, Kangiella aquimarina and Kangiella taiwanensis were 19.8%, 19.1% and 18.7%, respectively. The results of 16S rRNA gene phylogeny, phenotypic characterizations, chemotaxonomic characterization and genome features indicate that strain PIT represents a novel specie of the genus Kangiella, for which the name Kangiella shandongensis sp. nov. is proposed. The type strain is PIT (KCTC 82509T = MCCC 1K04352T).

The present work was aimed to study the effect of melatonin pre-treatments on oxidative stress modulation, cadmium (Cd) accumulation, and tolerance inAbutilon theophrastiMedicus under the hydroponic system. Application of substances that can modulate the harmful effects of Cd on plant yield and reduce its accumulation in the edible parts is of particular importance. Therefore, the Abutilon pre-treated with 0.1mM melatonin were exposed to 200μM, 400μM, 800μM Cd. Our results showed that 0.1mM melatonin led to positive effects on 200μM and 400μM Cd tolerance, including a significant increase in root activity andperoxidase (POD) activity and a significant decrease in malondialdehyde (MDA) content. Withthe help of melatonin, the enrichment factor (BCF) significantly decreased, reducing the content in the ground and roots. At least in our experiment conditions, this information appears to be useful for healthy food production.

Formamidinium methylammonium lead iodine (FAMAPbI3) based perovskite solar cells have reached phenomenal efficiencies recently. However, it is difficult to form pure black α-phase perovskite by solution method. Meanwhile, the formed polycrystalline FAMAPbI3 film often has large amount of grain boundaries, which can consist dangling bonds and iodide ions. Under illumination and heat, iodide ions can easily migrate and oxidize to form iodine, thus decompose the structure of perovskite and reduce the device performance. Herein, hydrazine chloride (HACl) as an additive is employed to promote favorable grain orientation during the growth of perovskite crystals. From grazing incidence wide-angle X-ray scattering (GIWAXS) and scanning electron microscope (SEM), HACl can facilitate strong diffraction signals along crystallographic planes (1 0 0) and (2 0 0) indicating a strengthened lattice structure for α-phase FAPbI3 and significantly decrease the grain boundaries for reduced carrier recombination. Consequently, the perovskite solar cells (PSCs) with optimized content of HACl lead to a champion power conversion efficiency (PCE) of 22.32% (certified PCEs of 21.59%) in a mesoporous device based on (FAPbI3)0.95(MAPbBr3)0.05 perovskite solar cells. Furthermore, from UV–vis and XPS spectrum, HACl can reduce iodine (I0) to iodide (I-) effectively, meaning the process of decomposition of FAMAPbI3-based perovskite has been greatly inhibited. As a result, unencapsulated device can retain 95% of its original power conversion efficiency after 1400 h of continuous one-sun illumination. Meanwhile, thermal (60 °C) stability is also greatly improved by maintaining 90% of initial efficiency after aging for 1400 h.

Background Atherosclerosis is characterized by chronic inflammation in vascular wall. Previous studies suggest that Kuwanon G (KWG) exerts anti-inflammatory activities. However, the effect of KWG on atherosclerosis remains unexplored. Aims To explore whether KWG affects macrophage foam cell formation in vitro and atherogenesis in vivo. Methods RAW 264.7 macrophages were stimulated with ox-LDL for 24 h to induce foam cell formation and treated with KWG. Foam cell formation was determined by ORO staining and enzymatic analysis. Pro-inflammatory cytokines mRNA levels were tested by Real-time PCR method. Further molecular mechanism was investigated using Western blot. In vivo, ApoE−/− mice were fed with high-fat diet and intraperitoneally injected with KWG. Atherosclerotic lesion was accessed by H&E and ORO staining. Plaque composition was evaluated by immunohistochemistry and Sirius Red staining. Serum lipid profile and inflammatory cytokines were evaluated by enzymatic method and ELISA. Results KWG significantly decreased intracellular lipid accumulation and inflammatory cytokines mRNA levels in macrophages through enhancing LXRα-ABCA1/ABCG1 pathway and inhibiting NFκB activation. Administrated with KWG remarkably reduced the atherosclerotic lesion areas and macrophage content in the plaque of high-fat diet fed ApoE−/− mice. KWG also reduced hyperlipidemia and serum inflammatory cytokines in vivo. Conclusion Taken together, these data highlight that KWG can attenuate atherosclerosis through inhibiting foam cell formation and inflammatory response.

Although incorporating multiple halogen (bromine) anions and alkali (rubidium) cations can improve the open-circuit voltage (Voc ) of perovskite solar cells (PSCs), severe voltage loss and poor stability have remained pivotal limitations to their further commercialization. In this study, acetylcholine (ACh+ ) is anchored to the surface of a quadruple-cation perovskite to provide additional electron states near the valence band maximum of the perovskite surface, thereby enhancing the band alignment and minimizing the Voc loss significantly. Moreover, the quaternary ammonium and carbonyl units of ACh+ passivate the antisite and vacancy defects of the organic/inorganic hybrid perovskite. Because of strong interactions between ACh+ and the perovskite, the formation of lead clusters and the migration of halogen anions in the perovskite film are suppressed. As a result, the device prepared with ACh+ post-treatment delivers a power conversion efficiency (PCE) (21.56%) and a value of Voc (1.21 V) that are much higher than those of the pristine device, along with a twofold decrease in the hysteresis index. After storage for 720 h in humid air, the device subjected to ACh+ treatment maintained 70% of its initial PCE. Thus, post-treatment with ACh+ appears to be a useful strategy for preparing efficient and stable PSCs.

The chemical property of cinnamaldehyde is unstable in vivo, although early experiments have shown its obvious therapeutic effects on viral myocarditis (VMC). To overcome this problem, we used cinnamaldehyde as a leading compound to synthesize derivatives. Five derivatives of cinnamaldehyde were synthesized: 4-methylcinnamaldehyde (1), 4-chlorocinnamaldehyde (2), 4-methoxycinnamaldehyde (3), α-bromo-4-methylcinnamaldehyde (4), and α-bromo-4-chlorocinnamaldehyde (5). Neonatal rat cardiomyocytes and HeLa cells infected by coxsackievirus B3 (CVB3) were used to evaluate their antiviral and cytotoxic effects. In vivo BALB/c mice were infected with CVB3 for establishing VMC models. Among the derivatives, compound 4 and 5 inhibited the CVB3 in HeLa cells with the half-maximal inhibitory concentrations values of 11.38 ± 2.22 μM and 2.12 ± 0.37 μM, respectively. The 50% toxic concentrations of compound 4 and 5-treated cells were 39-fold and 87-fold higher than in the cinnamaldehyde group. Compound 4 and 5 effectively reduced the viral titers and cardiac pathological changes in a dose-dependent manner. In addition, compound 4 and 5 significantly inhibited the secretion, mRNA and protein expressions of inflammatory cytokines TNF-α, IL-1β and IL-6 in CVB3-infected cardiomyocytes, indicating that brominated cinnamaldehyde not only improved the anti-vital activities for VMC, but also had potent anti-inflammatory effects in cardiomyocytes induced by CVB3.

We report a new protocol for the fluoroalkylation of alkenes and alkynes by using 2-bromophenol as a catalyst. This reaction can be tailored for different reaction modes by altering the base and solvent, which feature a wide substrate scope and excellent functional group tolerance with high chemo- and regioselectivities. We further propose a mechanism involving an electron donor-acceptor (EDA) complex.

The kinetics of extracellular enzymes produced by soil microorganisms regulate soil organic matter decomposition and other ecosystem functions. Atmospheric nitrogen (N) deposition creates a soil environment with elevated reactive N, which is expected to affect the kinetic parameters (Vmax and Km) of hydrolytic and polyphenol oxidative enzymes, as well as soil microbial respiration. We measured the Vmax and Km of seven soil hydrolytic enzymes and polyphenol oxidase (PPO), as well as soil microbial respiration and physiochemical properties, in a temperate steppe after 15 years of multi-level N addition treatments. As the N addition increased, the Vmax of most carbon (C)-degrading and N-degrading hydrolytic enzymes decreased, and this was associated with a decline in soil pH. In contrast, the Vmax of acid phosphatase (AP) increased with increasing N addition. Higher N addition was associated with lower Km of most hydrolytic enzymes, expect for AP and β-xylosidase (BX). There was a quadratic relationship between N addition and the Vmax and Km of PPO, which reached a maximum with the addition of 8 g ;N m−2 y−1, and decreased at higher N addition levels. Structural equation modeling indicated that the decline in soil microbial respiration with increasing N deposition was directly mediated by the BG kinetics, due to the fact N-induced acidification negatively impacted the Vmax and Km of BG. Our empirical data on soil enzyme (i.e., Vmax, Km) and its relationship with microbial respiration should be useful for modelling how microbes and substrates interact to regulate soil carbon cycling under N enrichment.

Hypoxic pulmonary vasoconstriction (HPV) can be modulated by Rho/Rho kinase signaling, which can alter HPV vascular function via regulating myosin light chain phosphorylation, in a manner generally believed to be Ca2+-independent. We hypothesized that the RhoA/ROCK signaling pathway also can regulate HPV vascular function via a Ca2+-dependent mechanism, signaling through the functional transient receptor potential canonical (TRPC) channels. In this study, male BALB/c mice were exposed to normoxic or 10% oxygen (hypoxic) conditions for six weeks, after which systolic pressure and right ventricular hypertrophy were assessed. Transient intracellular calcium was monitored using a fluorescence imaging system. Muscle tension was measured with a contractile force recording system, and protein expression was assessed by immunoblotting. We found that the expressions of RhoA and ROCK were increased in mouse pulmonary arteries (PAs) under conditions of chronic hypoxia. Inhibition of the RhoA/ROCK signaling pathway prevented the development of hypoxic pulmonary hypertension (HPH), as evidenced by significantly reduced PA remodeling and pulmonary vasoconstriction. Immunoblotting results revealed that inhibition of the RhoA/ROCK signaling pathway significantly decreased the expression of HIF-1α. Knockdown of HIF-1α down-regulated the expression and function of the TRPC1 and TRPC6 channels in PASMCs under conditions of hypoxia. Contraction of the PAs and a Ca2+ influx into PASMCs through either receptor- or store-operated Ca2+ channels were also increased after hypoxia. However, RhoA/ROCK inhibitors markedly attenuated these changes. These results indicate that inhibition of the RhoA/ROCK signaling pathway ameliorates HPH via HIF-1α-dependent functional TRPCs.

Xanthine oxidase, an enzyme present in significant levels in the intestine and liver, metabolizes hypoxanthine to xanthine and xanthine to uric acid in the purine catabolic pathway. An inhibitory compound acting against xanthine oxidase was isolated from sweet white clover (Melilotus albus) by bioassay and high-performance liquid chromatography guided separation. It was identified as tricin by spectroscopic analysis. Tricin possessed a potent xanthine oxidase inhibitory activity with an IC50 value of 4.13 &mu, M. Further inhibition kinetics data indicated it to be a mixed-type inhibitor and Ki and KI values were determined to be 0.47 &mu, M and 4.41 &mu, M. To find a rich source of tricin, the distribution of tricin in seven different tissues from four Gramineae species was investigated by high-performance liquid chromatography analysis. The highest amount (1925.05 mg/kg dry materials) was found in the straw of wheat, which is considered as a potentially valuable source of natural tricin.

One new capsaicinoid, N-vanillyl-4E,6E-dien-8-methylnonanamide (4), along with nine known capsaicinoids, capsaicin (1), dihydrocapsaicin (2), N-vanillyloctanamide (3), nordihydrocapsaicin (5), N-vanillyldecanamide (6), homocapsaicin (7), N-vanillyl-4,8-dimethylnonanamide (8), homodihydrocapsaicin II (9), and homodihydrocapsaicin I (10) were isolated from the fruits of Capsicum annuum using semi-preparative high-performance liquid chromatography. The structural characterizations of the isolated compounds were elucidated by spectroscopic data and comparison with the literatures. Bioassays showed that the isolated capsaicinoids significantly reduced the radical length of Lactuca sativa seedling, this inhibition being dose-dependent.

Two heterometallic uranium oxyfluorides with hybrid networks were hydrothermally synthesized by incorporating two imidazoles, 1-(biphenyl-4-yl)-1H-imidazole (bpi) and 1,4-di(1H-imidazol-1-yl)benzene (dib), formulated as Zn(bpi)2(UO2)2(H2O)F6 (1) and Zn(dib)(UO2)F4·0.5H2O (2). Compound 1 consists of chains of edge-sharing UO2F5 and UO2F4(H2O) pentagonal bipyramids, which are linked by Zn(bpi)2 moieties to form the sheet structure with decorated bpi. While in compound 2, sheets of edge-sharing dimers of UO2F5 pentagonal bipyramids and ZnF3N2 polyhedra are linked by dib, creating a pillared three-dimensional framework. The two compounds represent the few examples of heterometallic uranium oxyfluorides incorporating organic ligands. The syntheses, structure as well as the IR spectra, UV–vis spectra and luminescent properties of the bimetallic uranium oxyfluorides are studied.

A new series of uranium coordination polymers have been hydrothermally synthesized by using 4,4'-oxidiphthalic acid (H4L) in the presence of N-bearing species, namely, (H(2)dpa)UO2L.3H(2)O (1), (H(2)dib)UO2L.H2O (2), (H(2)bbi)(UO2)L.3H(2)O (3), (H(2)dib)(dib)(0.5)[UO2L(dib)].3H(2)O (4), (H(2)bbi)(U2O5)L.2H(2)O (5), and (Hbpi)(2)(UO(2)F())2L (6) [dpa = di(pyridin-4-yl)amine, dib = 1,4-di(1H-imidazol-1-yl)benzene, bbi = 1,1'-(1,4-butanediyl)bis(imidazole), and bpi = 1-(biphenyl-4-yl)-1H-imidazole]. Compounds 13 exhibit the ribbon structures with dpa, dib, and bbi as the templates, respectively. Compound 4 represents a one-dimensional chain assembly of uranyl centers, L ligands, and coordinated dib molecules. Compound 5 contains the tetranuclear motifs of edge-sharing of two UO7 pentagonal and two UO8 hexagonal bipyramids, which are linked by L ligands forming a layered structure with bbi as the template. Compound 6 forms a two-dimensional arrangement, in which the chain structures of edge-sharing UO5F2 pentagonal bipyramids are pillared by L ligands. Luminescence studies reveal the characterized green light emission from uranyl centers for these uranyl carboxylates. Moreover, the excellent visible light photodegradation activities for RhB are displayed by these coordination polymers.

A new imidazole-based zinc complex, synthesized using hydro­thermal methods, exhibits luminescent behaviour., The mononuclear title compound, [ZnCl2(C15H12N2)2], was synthesized by reaction of zinc chloride and 1-(biphenyl-4-yl)-1H-imidazole (bpi) under hydro­thermal conditions. The ZnII atom is tetra­hedrally coordinated by the free imidazole N atoms of two bpi ligands and by two Cl atoms. The bpi ligands are not planar, with dihedral angles of 37.52 (14) and 42.45 (14)° between the phenyl rings and 37.13 (14) and 40.05 (14)° between the phenyl rings and the attached imidazole rings, respectively. Mutual π–π inter­actions, with a centroid-to-centroid distance of 3.751 (2) Å between the phenyl and imidazole rings of neighbouring ligands, are present, leading to dimers that are arranged in rows parallel to [-211].

Polyacrylamide (polymer) solution which has different relative molecular mass and mass concentration in porous media has been studied in seepage flow experiment. Due to differences in pressure drop at different seepage velocities, the effective viscosities of different polymer solutions are calculated. Rheological behaviors of polymer solution changes in different mass concentration and relative molecular mass in porous media are analyzed. It is indicated that in the range of Darcy seepage velocity, acceleration is increasing during the process of pressure drop on both sides of core is resulted from the increase of flow rate during percolation, its effective viscosity first decreased, then increased with the increases of shear rate at range of Darcy velocity. Higher the relative molecular mass and mass concentration lead greater the effective viscosity.

Diabetic nephropathy (DN) is one of the major complications of diabetes mellitus (DM). This study aimed to explore the effects of corosolic acid (CA) on the renal damage of DM and the mechanisms behind these effects. The renoprotective effect of CA was investigated in type 1 diabetic rats and db/db mice. The kidneys and glomerular mesangial cells (GMCs) were used to study the proliferation of GMCs by immunostaining and MTT assay. Further immunoblotting, siRNA, qPCR analysis and detecting of NADPH oxidase activity and reactive oxygen species (ROS) generation were performed to explore relevant molecular mechanisms. In CA-treated diabetic animals, diabetes-induced albuminuria, increased serum creatinine and blood urea nitrogen were significantly attenuated and glomerular hypertrophy, mesangial expansion and fibrosis were ameliorated. Furthermore, CA significantly inhibited proliferation of GMCs and phosphorylation of ERK1/2 and p38 MAPK in both diabetic animals and high glucose (HG)-induced GMCs. CA also normalized Δψm and inhibited HG-induced NADPH oxidase activity, ROS generation and NOX4, NOX2, p22phox and p47phox expression. More importantly, CA inhibited GMC proliferation mediated by NADPH/ERK1/2 and p38 MAPK signaling pathways. These findings suggest that CA exert the protective effect on DN by anti-proliferation resulted from inhibition of p38 MAPK- and NADPH-mediated inactivation of ERK1/2.

Soluble guanylate cyclase (sGC) is a critical heme-containing enzyme involved in NO signaling. The dimerization of sGC subunits is necessary for its bioactivity and its mechanism is a striking and an indistinct issue. The roles of heme domain cysteines of the sGC on the dimerization and heme binding were investigated herein. The site-directed mutations of three conserved cysteines (C78A, C122A and C174S) were studied systematically and the three mutants were characterized by gel filtration analysis, UV–vis spectroscopy and heme transfer examination. Cys78 was involved in heme binding but not referred to the dimerization, while Cys174 was demonstrated to be involved in the homodimerization. These results provide new insights into the cysteine-related dimerization regulation of sGC.

The hollow-triangle PA6 composite shaped fiber produced by high-speed spinning with semi-dull polyamide 6 chips was designed and developed in our lab. Both the morphological structure and the rebound resilience of the fiber were observed and analyzed. Meanwhile, the weak acid, neutral and disperse dyes were applied to in the dyeing test. The results showed that the hollow-triangle fiber had a high degree of profile and good bulkiness. Furthermore, the immediate elastic recovery and total elastic recovery rate of the fiber were large. When stretched by 5%, the immediate elastic deformation of this fiber was 86.4% and its elastic recover rate was up to 100%, which is obviously better than that of the general PA6 fiber. Besides, the dyeing ability of the hollow-triangle PA6 fiber was nearly the same as that of the general one when it was dyed with different dyes under the normal technical conditions.

The object of this research is to investigate the factors influencing the hydrolysis of corn stover by dilute sulfuric acid and the types of sugars existed in hydrolysate. Experiment results showed that the optimal conditions were hydrolysis temperature 120°C, stover size 20-40 mesh, soak time 36h, reaction time 100 min, H2SO4concentration 1.5% and solid-liquid ratio 1:8. Sugars gained in the hydrolysate were xylose 3.0%, glucose 0.71%, mannose 0.12% and galactose 0.32% determined by capillary electrophoresis.

The chemically modified polysaccharides including sulfated phosphorylated carboxymethylated acetylated and sulfonylated derivatives were prepared from a neutral polysaccharide (PD) extracted from Polygonatum cyrtonema Hua These compounds were characterized by FT-IR H-1 NMR and C-13 NMR spectroscopy Antiherpetic activities of natural and modified P cyrtonema polysaccharide against herpes simplex virus (HSV) Induced by cyclophosphamide (CP) were then evaluated on vero cells using cytopathic effect (CPE) inhibition assay The phorphorylated derivative (P-PD) and sulfated derivative (S-PD) exhibited significant inhibitory activity against HSV in comparison with the native ones especially P-PD presented better antiviral potency In addition the sulfonylated derivative (Ts-PD) was found to be as effective as PD and the acetylated derivative (Ac-PD) to be slightly less antiviral effective whereas carboxymethylated derivative (C-PD) was shown to be almost inactive The results indicated that the types of function groups appeared to be very important for the antiherpetic activity of polysaccharides (C) 2010 Elsevier Ltd All rights reserved

CNT (carbon nanotube) was purified by acid washing method and then dispersed in alcohol. Sm2Zr2O7-CNT composite powders containing different amounts of CNT were synthesized by corprecipitation method and hot-press sintering were selected to prepare the composites. The density and thermal conductivity of the samples were tested. The micro-morphology and phase structure of composites were characterized by field emission scanning electron microscope and X-ray diffraction, respectively. Based on these experiments and theoretical analyses, the influences of carbon nanotube on the micro-morphology, phase structure and thermal conductivity of Sm2Zr2O7-CNT composite were revealed. Results showed that the carbon nantube uniformly dispersed in Sm2Zr2O7 matrix and the thermal conductivity of composites varied with the different amounts of CNT. In this article, the variation of thermal conductivity can be explained by the comprehensive evaluation of Sm2Zr2O7, CNT, pore and the heterogeneous interfaces thermal resistance between matrix and additives.

A model to calculate the curvature of H 2 O adsorption-induced bending for a metal/silicon nanocantilever is proposed based on atomic and molecular interaction. Part of the potential of both adsorbates and substrate transfers to the elastic energy of the cantilever, and the total energy of the system reaches a minimum value when adsorption is stable. According to this principle the model is developed to calculate H 2 O adsorption-induced curvature of the nanocantilever. The model was tested with the molecular dynamics method using Material Studio software. The results agree with theoretical value. This model gives us a simple method to calculate adsorption-induced bending of the nanocantilever.

Summary Rapid high-performance liquid chromatographic methods with evaporative light scattering detection (HPLC-ELSD) and electrospray ionization multistage mass spectrometry (HPLC-ESI-MSn) have been established and validated for simultaneous qualitative and quantitative analysis of eight steroidal saponins in ten batches of Gongxuening capsule (GXN), a widely commercially available traditional Chinese preparation. The optimum chromatographic conditions entailed use of a Kromasil C18 column with acetonitrile-water (30:70 to 62:38, υ/υ) as mobile phase at a flow rate of 1.0 mL min−1. The drift tube temperature of the ELSD was 102°C and the nebulizing gas flow rate was 2.8 L min−1. Separation was successfully achieved within 25 min. LC-ESI-MSn was used for unequivocal identification of the constituents of the samples by comparison with reference compounds. The assay was fully validated for precision, repeatability, accuracy, and stability, then successfully applied to quantification of the eight compounds i...

AIM: To investigate the chemical constituents of Psammosilene tunicoides W. C. Wu et C. Y. Wu. METHODS: Compounds were isolated by silica gel, Sephadex LH-20 and Rp-C18 column chromatography and the structures were elucidated by ESI-MS, EI-MS and NMR methods. RESULTS: Three compounds were isolated and identified as triterpenoid saponins: 3-O-β-D-galactopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3)]-β-D-6-O-methylglucuronopyranosyl-gypsogenin (1), 2α-hydroxyursolic acid (2), tormentic acid (3). CONCLUSION: Compound 1 is a new triterpenoid saponin while compounds 2 and 3 are isolated from this genus for the first time.

Two new pentacyclic triterpenoids, 3α, 30-dihydroxylup-20(29)-en-27-oic acid (1) and (20S)-3α, 29-dihydroxylupan-27-oic acid (2) were isolated from the whole herbs of Potentilla discolor Bunge. The structures of these two new compounds were elucidated, and complete assignments of the 1H and 13C NMR spectroscopic data were achieved by 1D and 2D NMR experiments (HSQC, HMBC, 1H1HCOSY and ROESY). Copyright © 2008 John Wiley & Sons, Ltd.

A new spirostanol steroidal saponin, named maireioside A ( 1 ), together with three known steroidal saponins, hypoglaucin G ( 2 ), parisaponin I ( 3 ), and diosgenin-3- O -α- l -rhamnopyranosyl (1→4)-[α- l -rhamnopyranosyl (1→2)]-β- d -glucopyranoside ( 4 ), were isolated from the rhizomes of Paris mairei . The structure elucidation was accomplished by 1D and 2D NMR methods, HR-ESI–MS, and hydrolysis.

5.29 (1H, d, J = 5.2, H-6), 3.83 (1H, m, H-3), 3.50 (2H, m, H-26), 1.75 (3H, d, J = 6.2, CH 3 -6″), 1.59 (3H, d, J = 5.4, CH 3 -6′″), 1.58 (3H, d, J = 5.9, CH 3 -6″″), 1.21 (3H, d, J = 7.2, CH 3 -21), 1.07 (3H, s, CH 3 -19), 0.94 (3H, s, CH 3 -18), 0.67 (3H, d, J = 5.8

Three new oleanane-type triterpenoid saponins, ilexhainanoside C, D and E, all with 24, 28-dioic acid groups, were isolated from the leaves of Ilex hainanensis. They were 3β-hydroxyolean-12-ene-24, 28-dioic acid-28-O-β-D-glucopyranoside(1), 3β, 19α-dihydroxyolean-12-ene-24, 28-dioic acid-28-O-β-D-glucopyranoside(2) and 3β, 29-dihydroxyolean-12-ene-24, 28-dioic acid-28-O-β-D-glucopyranoside(3). The structures of these three new compounds were elucidated and complete assignments of the 1H and 13C NMR spectroscopic data were achieved by 1D and 2D NMR experiments [heteronuclear single quantum coherence (HSQC), HMBC and rotational nuclear Overhauser effect spectroscopy (ROESY)]. Copyright © 2008 John Wiley & Sons, Ltd.

A series of benzimidazole derivatives bearing a heterocyclic ring imidazole (1), 5-chloroimidazole (2), 1,2,4-triazol (3), and imidazoline (4) were synthesized and evaluated for angiotensin II antagonistic activities. The synthetic compounds 1-4 were biologically evaluated in vitro using an AT(1) receptor binding assay, where compounds 1 and 3 provided weak binding affinity, compound 2 showed moderate binding affinity, and compound 4 showed good binding affinity. Moreover, compound 4 was found to be almost equipotent with telmisartan in vivo biological evaluation study.