Purification,Chemical Characterization,and Bioactivity of an Extracellular Polysaccharide Produced by the Marine Sponge Endogenous Fungus <Emphasis Type="Italic">Alternaria</Emphasis> sp. SP-32

Marine sponges are ancient and simple multicellular filter-feeding invertebrates attached to solid substrates in benthic habitats and host a variety of fungi both inside and on their surface because of its unique ingestion and digest system. Investigation on marine sponge-associated fungi mainly focused on the small molecular metabolites, yet little attention had been paid to the extracellular polysaccharides. In this study, a homogeneous extracellular polysaccharide AS2-1 was obtained from the fermented broth of the marine sponge endogenous fungus Alternaria sp. SP-32 using ethanol precipitation, anion-exchange, and size-exclusion chromatography. Results of chemical and spectroscopic analyses showed that AS2-1 was composed of mannose, glucose, and galactose with a molar ratio of 1.00:0.67:0.35, and its molecular weight was 27.4 kDa. AS2-1 consists of a mannan core and a galactoglucan chain. The mannan core is composed of (1→6)-α-Manp substituted at C-2 by (1→2)-α-Manp with different degrees of polymerization. The galactoglucan chain consists of (1→6)-α-Glcp residues with (1→6)-β-Galf residues attached to the last glucopyranose residue at C-6. (1→6)-β-Galf residues have additional branches at C-2 consisting of disaccharide units of (1→2)-β-Galf and (1→2)-α-Glcp residues. The glucopyranose residue of the galactoglucan chain is linked to the mannan core. AS2-1 possessed a high antioxidant activity as evaluated by scavenging of 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radicals in vitro. AS2-1 was also evaluated for cytotoxic activity on Hela, HL-60, and K562 cell lines by the MTT and SRB methods. The investigation demonstrated that AS2-1 was a novel extracellular polysaccharide with different characterization from extracellular polysaccharides produced by other marine microorganisms.     

Effects of manganese on the microstructures of Chenopodium ambrosioides L., A manganese tolerant plant

Chenopodium ambrosioides L. can tolerate high concentrations of manganese and has potential for its use in the revegetation of manganese mine tailings. Following a hydroponic investigation, transmission electron microscopy (TEM)-energy disperse spectroscopy (EDS) was used to study microstructure changes and the possible accumulation of Mn in leaf cells of C. ambrosioides in different Mn treatments (200, 1000, 10000 μmol·L^?1). At 200 μmol·L^?1, the ultrastructure of C. ambrosioides was clearly visible without any obvious damage. At 1000 μmol·L^?1, the root, stem and leaf cells remained intact, and the organelles were clearly visible without any obvious damage. However, when the Mn concentration exceeded 1000 μmol·L^?1 the number of mitochondria in root cells decreased and the chloroplasts in stem cells showed a decrease in grana lamellae and osmiophilic granules. Compared to controls, treatment with 1000 μmol·L^?1 or 10000 μmol·L^?1 Mn over 30 days, gave rise to black agglomerations in the cells. At 10000 μmol·L^?1, Mn was observed to form acicular structures in leaf cells and intercellular spaces, which may be a form of tolerance and accumulation of Mn in C. ambrosioides. This study has furthered the understanding of Mn tolerance mechanisms in plants, and is potential for the revegetation of Mn-polluted soils.     

Resolution of Rac‐Bambuterol via Diastereoisomeric Salt Formation with o‐Chloromandelic Acid and Differences in the Enantiomers' Pharmacodynamical Effects in Guinea Pigs and Beagles

In this study an enantioseparation method for rac‐bambuterol (5‐(2‐(tert‐butylamino)‐1‐hydroxyethyl)‐1,3‐phenylene bis(dimethylcarbamate)) via diastereoisomeric salt formation with o‐chloromandelic acid was developed. The enantiomeric excess (ee) values and chemical purities of the desired products were confirmed by high‐performance liquid chromatography (HPLC) using chiral stationary phase and reverse‐phase HPLC analyses, respectively. The ee values and the chemical purities both exceeded 99%. Animal experiments showed that (R)‐bambuterol was a potent inhibitor for histamine‐induced asthma reactions. (S)‐bambuterol was ineffective in relaxing the airways. Both enantiomers increased heart rates in beagles. Therefore, replacing rac‐bambuterol with (R)‐bambuterol could be beneficial for asthma patients. Chirality 28:306–312, 2016. © 2016 Wiley Periodicals, Inc.     

Distribution of Cu fraction in sediments using Suaeda heteroptera - Nereis succinea combination: A greenhouse study

A knowledge of the total amount of heavy metals is not enough to assess the environmental impact of polluted soils. Therefore, the determination of Cu fractions in sediment is important to evaluate its behavior in the environment and its mobilization capacity. The distribution of Cu (II) fractions in the sediment was studied in a laboratory simulation experiment. The results indicated that the distribution of Cu fractions was related to the concentration of Cu in sediments. In the Suaeda heteroptera group, the content of exchangeable and carbonate-bound were reducing, while the Fe-Mn oxide- and organic matter-bound were basically raising. In the Nereis succinea group, the content of Fe-Mn oxide- and organic matter-bound were from raising to reducing, and the residual was basically reducing with the increasing Cu concentrations. Generally speaking, the existence of N. succinea could enhance the uptake of Cu in the coastal sediment planted with S. heteroptera. When S. heteroptera and N. succinea in combination, effect of S. heteroptera and N. succinea on Cu fractions in sediments was significantly higher than the two working singly.     

Investigation of B,C-ring truncated deguelin derivatives as heat shock protein 90 (HSP90) inhibitors for use as anti-breast cancer agents

On the basis of deguelin, a series of the B,C-ring truncated surrogates with N-substituted amide linkers were investigated as HSP90 inhibitors. The structure activity relationship of the template was studied by incorporating various substitutions on the nitrogen of the amide linker and examining their HIF-1α inhibition. Among them, compound 57 showed potent HIF-1α inhibition and cytotoxicity in triple-negative breast cancer lines in a dose-dependent manner. Compound 57 downregulated expression and phosphorylation of major client proteins of HSP90 including AKT, ERK and STAT3, indicating that its antitumor activity was derived from the inhibition of HSP90 function. The molecular modeling of 57 demonstrated that 57 bound well to the C-terminal ATP-binding pocket in the open conformation of the hHSP90 homodimer with hydrogen bonding and pi-cation interactions. Overall, compound 57 is a potential antitumor agent for triple-negative breast cancer as a HSP90 C-terminal inhibitor.     

Mechanically Activated Piezo Channels Mediate Touch and Suppress Acute Mechanical Pain Response in Mice

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