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Tian J.,Northeast Agricultural University | Tian J.,CAS Institute of Microbiology | Chen H.,CAS Institute of Microbiology | Chen H.,Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development | And 7 more authors.
Applied Microbiology and Biotechnology | Year: 2016

Many novel microbial nature products were discovered from Actinobacteria by genome mining methods. However, only a few number of genome mining works were carried out in rare actinomycetes. An important reason precluding the genome mining efforts in rare actinomycetes is that most of them are recalcitrant to genetic manipulation. Herein, we chose the rare marine actinomycete Streptosporangium sp. CGMCC 4.7309 to explore its secondary metabolite diversity by genome mining. The genetic manipulation method has never been established for Streptosporangium strains. At first, we set up the genetic system of Streptosporangium sp. CGMCC 4.7309 unprecedentedly. The draft genome sequencing of Streptosporangium sp. CGMCC 4.7309 revealed that it contains more than 20 cryptic secondary metabolite biosynthetic clusters. A type II polyketide synthases-containing cluster (the hex cluster) was predicted to encode compounds with a pentangular polyphenol scaffold by in silico analysis. The products of the hex cluster were uncovered by comparing the metabolic profile of Streptosporangium sp. CGMCC 4.7309 with that of the hex30 inactivated mutant, in which a key ketoreductase gene was disrupted. Finally, three pentangular polyphenols were isolated and named as hexaricins A (1), B (2), and C (3). The inconsistency of the stereochemistry of C-15 in hexaricins A, B, and C indicates a branch point in their biosynthesis. Finally, the biosynthetic pathway of the hexaricins was proposed based on bioinformatics analysis. © 2016 Springer-Verlag Berlin Heidelberg

Jiang X.,Guangxi University | Jiang X.,Guangxi University of Science and Technology | Jiang X.,Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development | Yang W.,Liuzhou LMZ Co. | And 5 more authors.
Biomedical Research (India) | Year: 2016

The in vitro antibacterial activity of ethanol extract from Bauhinia championii (Benth.) Benth growing in Guangxi, China, was evaluated against S. mutans using twofold agar dilution method. The present study showed that minimal inhibitory concentration was 12.5 mg/mL and there have significant inhibitory activity of adherence and acidogenicity against S. mutans when the extract concentration was greater than or equal to 3.13 mg/mL. These results indicate that Bauhinia championii (Benth.). Benth extract can significantly inhibit the growth, adherence and acidogenicity of S. mutans and might be used in the area of dental caries prevention and treatment in the future. © 2016, Scientific Publishers of India. All rights reserved.

Chen Z.,Guangxi University | Hu W.,Guangxi University | Wang M.,Guangxi University | Wang L.,Guangxi University | And 3 more authors.
Carbohydrate Research | Year: 2016

A glycosyl-rhodamine fluorescent probe with good water-solubility has been designed and synthesized through click reaction. Compared with control compound 1, the obtained target compound (RBGlc-3) could be independently applied for the detection of Hg2+ in water medium, and not disturbed by Ce3+, Eu3+, Ca2+, Cd2+, Fe2+, Ba2+, Co2+, Cu2+, Zn2+, Pb2+, Mg2+, Ni2+, K+, Ag+, Na+, NH4 +, CH3COO-, S2O4 2-, SO4 2-, SO3 2- and Cl-. 1:1 Stoichiometry is the most likely recognition mode of RBGlc-3 toward Hg2+ ion, and the OFF-ON fluorescent mechanism of RBGlc-3 is proposed. © 2016 Elsevier Ltd.

Zhou Y.,Guangxi University | Chen W.,Guangxi University | Shen Y.,Guangxi University | Wu X.,Guangxi University | And 3 more authors.
Journal of Magnetism and Magnetic Materials | Year: 2015

LixCu0.6Mg0.4-xFe2O4 (0.0≤x≤0.3) is obtained by calcining precursor oxalates over 900 °C in air. The precursor and its calcined products are characterized by thermogravimetry and differential scanning calorimetry, X-ray powder diffraction, scanning electron microscopy, and vibrating sample magnetometer. A high-crystallized LixCu0.6Mg0.4-xFe2O4 with a cubic structure is obtained when the precursor is calcined at 900 °C in air for 3 h. The lattice constants of the ferrites decrease after Li+ doping. Magnetic properties of LixCu0.6Mg0.4-xFe2O4 depend on the composition and calcination temperature. Cu0.6Mg0.4Fe2O4 obtained at 900 °C has the highest specific saturation magnetization value, 42.44 emu/g; remanence value of Li0.2Cu0.6Mg0.2Fe2O4 obtained at 900 °C is close to zero. © 2015 Elsevier B.V. All rights reserved.

Du C.-R.,Guangxi University | Lu D.-W.,Guangxi University | Shi K.,Guilin University of Electronic Technology | Chen D.-D.,Guangxi University | And 2 more authors.
Faguang Xuebao/Chinese Journal of Luminescence | Year: 2015

Because of the excellent properties and wide applications of cinnamamide medicines in clinic, three m-hydroxycinnamic acid derivatives were designed and synthetised by the reaction of m-hydroxybenzoic acid with different amino acids, respectively. Their structures were characterized by mass spectrometry, infrared spectroscopy, and nuclear magnetic resonance. The interaction mechanism of derivatives and human serum albumin (HSA) were investigated by AutoDock molecular docking, fluorescence spectroscopy and UV-visible absorption spectroscopy. The results of molecular docking represent that derivatives exist in the hydrophobic pocket of subdomain II A (site I) of HSA. Hydrogen bonds and van der Waals' forces are main acting forces and hydrophobic force is just the secondary consideration. The spectra experiment results indicate that the derivatives can form complexes with HSA respectively and strongly quench the intrinsic fluorescence of HSA through static quenching at different temperatures. Meanwhile, the secondary structure of HSA is influenced. The change in enthalpy (ΔH) and entropy (ΔS) suggest that hydrogen bonds and van der Waals forces are main acting forces. The molecular docking data are consistent with experimental results. © 2015, Science Press. All right reserved.

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