Marine-derived fungi are a treasure house for the discovery of structurally novel secondary metabolites with potential pharmaceutical value. In this study, a pair of new nor-bisabolane derivative enantiomers (±)-1 and two new phthalides (4 and 5), as well as four known metabolites, were isolated from the culture filtrate of the marine algal-derived endophytic fungus LD-201810. Their structures were established by detailed interpretation of spectroscopic data (1D/2D NMR and ESI-MS).
View Article and Find Full Text PDFFungi play an irreplaceable role in drug discovery in the course of human history, as they possess unique abilities to synthesize diverse specialized metabolites with significant medicinal potential. are well-studied filamentous fungi generally observed in nature, which are widely marketed as biocontrol agents. The secondary metabolites produced by have gained extensive attention since they possess attractive chemical structures with remarkable biological activities.
View Article and Find Full Text PDFA new pentaketide derivative, penilactonol A (), and two new hydroxyphenylacetic acid derivatives, (2'R)-stachyline B (2) and (2'R)-westerdijkin A (3), together with five known metabolites, bisabolane-type sesquiterpenoids 4-6 and meroterpenoids 7 and 8, were isolated from the solid culture of a marine alga-associated fungus LD-201810. Their structures were elucidated based on extensive spectroscopic analyses, including 1D/2D NMR and high resolution electrospray ionization mass spectra (HRESIMS). The absolute configurations of the stereogenic carbons in 1 were determined by the (Mo(OAc))-induced circular dichroism (CD) and comparison of the calculated and experimental electronic circular dichroism (ECD) spectra, while the absolute configuration of the stereogenic carbon in 2 was established using single-crystal X-ray diffraction analysis.
View Article and Find Full Text PDFMarine-derived fungi are considered to be valuable producers of bioactive secondary metabolites used as lead compounds with medicinal importance. In this study, chemical investigation of the seawater-derived fungus SW9 led to the isolation and identification of one new quinazolinone alkaloid, 2-(4-hydroxybenzyl)-4-(3-acetyl)quinazolin-one (), one new aromatic bisabolene-type sesquiterpenoid, () and one new chorismic acid analogue (), as well as two known alkaloids (compounds and ). Their structures were determined by extensive 1D/2D NMR and mass spectrometric data, and the absolute configurations of and were assigned by the analysis of ECD spectra aided by quantum chemical computations.
View Article and Find Full Text PDFTo enhance the structural diversity of isoflavonoids and provide more derivatives for the biological screening, a semisynthetic mixture was generated by diversification of the crude extract of Radix puerariae (Pueraria montana var. lobata) through the chemical reaction with hydrazine hydrate. Eleven 3,4-diarylpyrazoles (1-11) and two 5-phenyl-6-benzyldihydropyridazinones (12 and 13) were isolated from the semisynthetic mixture, and their structures were identified by spectroscopic methods in combination with X-ray crystallographic analysis.
View Article and Find Full Text PDFIn mid-August 2013, two H9N2 influenza viruses, named A/mink/Shandong/F6/2013 (Mk/SD/F6/13) and A/mink/Shandong/F10/2013 (Mk/SD/F10/13), were isolated from lung samples of 2 of 45 farmed mink exhibiting respiratory signs in mideastern Shandong province, China. The seroprevalence of antibodies to H9N2 in mink was 20% (53/265). Based on sequence analysis, the eight nucleotide sequences showed 99.
View Article and Find Full Text PDFTo investigate molecular epidemiology of DuCV in Cherry Valley ducks in China, the complete genomes of six DuCV strains, which were detected from Cherry Valley ducks in China between 2007 and 2008, were sequenced. Sequence and phylogenetic analysis were carried out to compare these six strains with another 27 DuCV strains from Mulard duck, Muscovy duck, Pekin ducks and Mule duck. The analysis showed that the six DuCV strains exhibited typical genetic features of the family of DuCV, such as a stem-loop structure, three major open reading frames (Rep, Cap and ORF3), four intergenic repeats and the conserved motifs for rolling circle replication and for the dNTP binding domain located in the Rep protein.
View Article and Find Full Text PDFInfection with duck circovirus (DuCV) is associated with growth retardation and developmental problems in farmed ducks. To detect DuCV-specific antibody in duck serum, an indirect enzyme-linked immunosorbent assay (iELISA) method was developed using the recombinant capsid protein antigen prepared by cloning the cap (Cap) gene of DuCV FJ0601 strain into pET-32a (+) vector and expressed in Escherichia coli. Using the optimized iELISA method, DuCV-specific antibodies were detected in 157 (12.
View Article and Find Full Text PDFThe clinical symptoms of infectious coryza are multiple and include nasal discharge, facial swelling, lacrimation, and anorexia. In general, the disease is not fatal to chicken; so, in experiments where animals are infected with Avibacterium paragallinarum, there have been debates about conducting the challenge model and evaluating the clinical signs. In this experiment, 150 chickens, aged 30 days, were randomly divided into different groups.
View Article and Find Full Text PDFThe genomic DNA extracted from chicken embryo fibroblasts (CEF) of SPF chickens from three chicken farms was used as template to amplify the ALV proviral DNA by PCR with four pairs of primers, high positive detection rates of gag - gene (29/46), pol - gene (27/46), env - gene (24/46) and LTR fragment (31/46) were achieved. Eight continuous and overlapping fragments were amplified from one DNA sample with 8 pairs of primers according to published sequences, then cloned into the TA vector and se quenced. The complete sequence of the whole genome of ALV strain SD0501 was established and analyzed with DNAstar software.
View Article and Find Full Text PDFIn order to study E. coli aerosol spreading from chicken houses to their surrounding air, air samples, including indoor and outdoor air (upwind 10 and 50 m as well as downwind 10, 50, 100, 200 and 400 m away) of 5 chicken houses were collected using six-stage Andersen microbial samplers and Reuter-Centrifugal samplers (RCS). E.
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