Search

A new cycloartane-type triterpenoid, 3β-acetoxy-9β,19-cyclolanost-24E-ene-1α,16β-diol-27-O-β-d-glucopyranoside (1), together with three known ones (2–4) were isolated from the aerial parts of Astragalus hoantchy. The structure of compound 1 was elucidated by detailed spectroscopic analyses including 1D and 2D NMR, HRESIMS, and IR experiments. All of the four compounds were isolated from A. hoantchy for the first time. The antifungal activities of compounds 1–4 against a phytopathogenic fungus (Alternaria solani) were evaluated with the result that compound 3 exhibited a moderate activity with an IC50 value of 284 μg/mL. [ABSTRACT FROM AUTHOR]

Stipa purpurea is among constructive endemic species in the alpine steppe on the Qinghai-Xizang Plateau. To reveal the fungal community structure and diversity in the rhizosphere and roots of this important grass and to analyze the potential influence of different habitats on the structure of fungal communities, we explored the root endophyte and the directly associated rhizosphere communities of S. purpurea by using internal transcribed spacer rRNA cloning and sequencing methods. We found that the roots of S. purpurea are associated with a diverse consortium of Basidiomycota (59.8%) and Ascomycota (38.5%). Most fungi obtained from rhizosphere soil in S. purpurea have been identified as Ascomycetes, while the high proportion detected in roots were basidiomycetous endophytes. The species richness, diversity, and evenness of fungal assemblages were higher in roots than in the rhizosphere soil. Fungi inhabiting the rhizosphere and roots of S. purpurea are significantly different, and the rhizosphere and endophyte communities are largely independent with little overlap in the dominant phyla or operational taxonomic units. Taken together, these results suggested that a wide variety of fungal communities are associated with the roots and rhizosphere soil of S. purpurea and that the fungal assemblages are strongly influenced by different habitats. [ABSTRACT FROM AUTHOR]

A strain SMrs28 was isolated from the rhizosphere soil of a toxic plant Stellera chamaejasme and identified as Bacillus sp. on the basis of morphological and partial 16S rRNA gene sequence analysis. The crude extract of SMrs28 fermentation broth showed strong nematocidal activities in preliminary test. To define the active nematocidal metabolites of SMrs28, a novel compound ( 1), 4-oxabicyclo[3.2.2]nona-1(7), 5,8-triene, along with five known compounds ( 2- 6), were isolated from the strain by various column chromatographic techniques and characterized on the basis of spectroscopic analysis. Results of the in vitro nematicidal tests showed that the metabolites presented different levels of activity at certain exposure conditions. Compounds ( 1- 3) displayed LC50 values of 904.12, 451.26, 232.98 µg/ml and 1594.0, 366.62, 206.38 µg/ml against Bursaphelenchus xylophilus and Ditylenchus destructor at 72 h, respectively. This is the first report of the nematicidal activity of the compounds as constituents of Bacillus sp.. Our findings help to find potential chemical structures to develop nematicides from microbial source for the management of nematode-infected plant diseases. [ABSTRACT FROM AUTHOR]

The Hequ Tibetan MastiffCanis lupus familiaris(Carnivora: Canidae) is a primitive breed of large dogs native to the northeastern Qinghai-Tibetan Plateau of China. In this study, its complete mitochondrial genome sequence has been assembled and characterized using high-throughput Illumina sequencing technology. The circular genome is 16 730 bp in length, and possesses all genomic components as typically found in most other metazoan mitogenomes. The gene arrangement is identical to those of most other vertebrates. Except forND4Lwith GTG as its start codon, all the other PCGs are initiated with an ATR (ATA/ATG) codon. Three distinct stop codons are employed, i.e. AGA forCYTB, TAA forATP6, ATP8, COX1, COX2, ND1, ND4L, ND5andND6, and an incomplete stop codon T forCOX3, ND2, ND3andND4. The nucleotide composition is asymmetric (31.6% A, 25.5% C, 14.2% G and 28.7% T) with an overall A + T content of 60.3%. These data would contribute to our better understanding its evolutionary history. [ABSTRACT FROM AUTHOR]