2,117 research outputs found
Poly[[bis(μ2-4-aminobenzenesulfonato-κ2 N:O)diaquamanganese(II)] dihydrate]
The title compound, {[Mn(NH2C6H4SO3)2(H2O)2]·2H2O}n, was prepared under mild hydrothermal conditions. The unique MnII ion is located on a crystallographic inversion center and is coordinated by two –NH2 and two –SO3 groups from four 4-aminobenzenesulfonate ligands and by two water molecules in the axial positions, forming a slightly distorted octahedral coordination environment. The 4-aminobenzenesulfonate anions behave as μ2-bridging ligands to produce a two-dimensional structure. In the crystal structure, intermolecular N—H⋯O, O—H⋯O and C—H⋯O hydrogen bonds link the layers into a three-dimensional network
Flemingia macrophylla Extract Ameliorates Experimental Osteoporosis in Ovariectomized Rats
Flemingia macrophylla (Leguminosae), a native plant of Taiwan, is used as folk medicine. An in vitro study showed that a 75% ethanolic extract of F. macrophylla (FME) inhibited osteoclast differentiation of cultured rat bone marrow cells, and the active component, lespedezaflavanone A (LDF-A), was isolated. It was found that oral administration of FME for 13 weeks suppressed bone loss in ovariectomized rats, an experimental model of osteoporosis. In addition, FME decreased urinary deoxypyridinoline concentrations but did not inhibit serum alkaline phosphatase activities, indicating that it ameliorated bone loss via inhibition of bone resorption. These results suggest that FME may represent a useful remedy for the treatment of bone resorption diseases, such as osteoporosis. In addition, LDF-A could be used as a marker compound to control the quality of FME
Diaquabis(2-carboxybenzoato-κO)nickel(II)
In the title compound, [Ni(C8H5O4)2(H2O)2], the NiII atom lies on an inversion centre and exhibits a square-planar geometry incorporating two phthalate and two water O atoms. The nickel complex is stabilized by intramolecular interactions involving water O atoms and H atoms of the phthalate groups. It forms one-dimensional zigzag chains along the b axis which are held together via π–π stacking interactions (3.647 Å) between the benzene rings of the phthalate groups. The adjacent chains are also hydrogen bonded, resulting in a three-dimensional supramolecular network
The first record of the family Euscorpiidae (Arachnida: Scorpiones) from Central China, with a key of Chinese species of the genus \u3cem\u3eScorpiops\u3c/em\u3e
The genus Scorpiops (Euscorpiidae) is recorded for the first time in Central China. Two immature specimens of a form belonging to Scorpiops hardwickii (Gervais, 1843) “complex” were collected from Huzhaoshan Mountains in Hubei Province. A discussion of Chinese species of genus Scorpiops is provided, as well as a key of Scorpiops from China
Exploring mycorrhizal fungi in walnut with a focus on physiological roles
Walnuts are an economically important forest tree used for timber and nut production, and the nut of fruits is rich in various nutrients, becoming one of the four important nuts in the world. Walnuts have deep roots, which can be colonized by either ectomycorrhizal fungi or arbuscular mycorrhizal fungi in the soil. These mycorrhizal fungi form beneficial symbioses in roots of walnut. A large number of ectomycorrhizal fungi have been identified, whilst Boletus edulis, Calvatia uiacina, and Cantharelles cibarius isolated from walnut orchards stimulated plant growth and gave the capacity of stress tolerance in walnut. Moreover, Carya illinoensis is a very good host plant for commercial production of truffles, especially Tuber indicum. In addition, ectomycorrhizal fungi accelerate plant growth and enhance potential stress tolerance of walnuts. Inoculation with arbuscular mycorrhizal fungi also showed the improvement of plant growth and nutrient acquisition of walnut, the enhancement of drought tolerance in walnut, nutrient redistribution under walnut interplanting patterns, and the delivery of juglone by mycorrhizal hyphae. A culturable in vitro arbuscular mycorrhizal like fungus Piriformospora indica also enhanced salt tolerance of walnut plants. In this mini-review, the physiological roles of mycorrhizal fungi, including arbuscular mycorrhizal fungi, ectomycorrhizal fungi and arbuscular mycorrhizal like fungus (P. indica) on walnut plants are summarized, and future outlooks in the field are proposed
Rice bacterial blight pathogen Xanthomonas oryzae pv. oryzae produces multiple DSF-family signals in regulation of virulence factor production
<p>Abstract</p> <p>Background</p> <p><it>Xanthomonas </it><it>oryzae </it>pv. <it>oryzae </it>(<it>Xoo</it>) is the causal agent of rice bacterial blight disease. <it>Xoo </it>produces a range of virulence factors, including EPS, extracellular enzyme, iron-chelating siderophores, and type III-secretion dependent effectors, which are collectively essential for virulence. Genetic and genomics evidence suggest that <it>Xoo </it>might use the diffusible signal factor (DSF) type quorum sensing (QS) system to regulate the virulence factor production. However, little is known about the chemical structure of the DSF-like signal(s) produced by <it>Xoo </it>and the factors influencing the signal production.</p> <p>Results</p> <p><it>Xoo </it>genome harbours an <it>rpf </it>cluster comprising <it>rpfB</it>, <it>rpfF</it>, <it>rpfC </it>and <it>rpfG</it>. The proteins encoded by these genes are highly homologous to their counterparts in <it>X. campestris </it>pv. <it>campestris </it>(<it>Xcc</it>), suggesting that <it>Xcc </it>and <it>Xoo </it>might use similar mechanisms for DSF biosynthesis and autoregulation. Consistent with <it>in silico </it>analysis, the <it>rpfF </it>mutant was DSF-deficient and the <it>rpfC </it>mutant produced about 25 times higher DSF-like activity than the wild type <it>Xoo </it>strain KACC10331. From the supernatants of <it>rpfC </it>mutant, we purified three compounds showing strong DSF-like activity. Mass spectrometry and NMR analysis revealed that two of them were the previously characterized DSF and BDSF; the third one was a novel unsaturated fatty acid with 2 double bonds and was designated as CDSF in this study. Further analysis showed that all the three DSF-family signals were synthesized via the enzyme RpfF encoded by <it>Xoo2868</it>. DSF and BDSF at a final concentration of 3 μM to the <it>rpfF </it>mutant could fully restore its extracellular xylanase activity and EPS production to the wild type level, but CDSF was less active than DSF and BDSF in induction of EPS and xylanase. DSF and CDSF shared a similar cell density-dependent production time course with the maximum production being detected at 42 h after inoculation, whereas the maximum production of BDSF was observed at 36 h after inoculation. When grown in a rich medium such as YEB, LB, PSA, and NYG, <it>Xoo </it>produced all the three signals with the majority being DSF. Whereas in nutritionally poor XOLN medium <it>Xoo </it>only produced BDSF and DSF but the majority was BDSF.</p> <p>Conclusions</p> <p>This study demonstrates that <it>Xoo </it>and <it>Xcc </it>share the conserved mechanisms for DSF biosynthesis and autoregulation. <it>Xoo </it>produces DSF, BDSF and CDSF signals in rich media and CDSF is a novel signal in DSF-family with two double bonds. All the three DSF-family signals promote EPS production and xylanase activity in <it>Xoo</it>, but CDSF is less active than its analogues DSF and BDSF. The composition and ratio of the three DSF-family signals produced by <it>Xoo </it>are influenced by the composition of culture media.</p
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