Search

We have investigated the impacts of 63 different low-molecular-weight compounds, most of them plant derived, on the in vitro expression of two antifungal biosynthetic genes by the plant-protecting rhizobacterium Pseudomonas fluorescens CHA0. The majority of the compounds tested affected the expression of one or both antifungal genes. This suggests that biocontrol activity in plant-beneficial pseudomonads is modulated by plant-bacterium signaling. [ABSTRACT FROM AUTHOR]

A 60-kDa extra-cellular laccase enzyme was purified to homogeneity from a liquid culture of Fomitioiria mediterranea, the main wood rot agent of the grapevine diseases esca. The enzyme exhibited thermal stability. Substrate specificity and inhibitor studies indicated that the enzyme was a typical fungal laccase. Several natural phenolic and polyphenolic compounds were oxidised by the isolated laccase. [ABSTRACT FROM AUTHOR]

Microextraction in packed syringe (MEPS) is a new technique for miniaturised solid‐phase extraction that can be connected online to GC or LC. In this work, a liquid polymer was used as coating polymer on a filter in a 10 µL and 250 µL syringe to handle small sample volumes (≤10 µL plasma). Ropivacaine in plasma samples was used as model substance. The validation of the methodology showed that the accuracy values of quality control samples (QC) were in the range of 103%–114% for GC‐MS, and 98–101% for LC‐MS‐MS. The precisions, given as relative standard deviation (R.S.D.) were in the range 1.9 to11% for Inter‐ and intra‐day precisions. The standard curves were obtained within the concentration ranges 5‐2,000 nM in human plasma samples. The regression correlation coefficients (R 2 ) for plasma samples were 0.99 for all runs using GC‐MS and LC‐MS‐MS. [ABSTRACT FROM AUTHOR]

Abstract: Two clerodane diterpenoids, Bafoudiosbulbins A 1, and B 2, together with five known compounds: tetracosanoic acid, 1-(tetracosanoyl)-glycerol, trans-tetracosanylferulate, β-sitosterol and 3-O-β-d-glucopyranosyl-β-sitosterol were isolated from the tubers of Dioscorea bulbifera L. var sativa. Their structures were established by spectroscopic methods (1D and 2D-NMR, MS) and X-ray crystallographic diffraction analysis of compound 1. The CH2Cl2-soluble portion of the crude extract and the two clerodanes were screened for anti-bacterial activity using both agar diffusion and broth dilution techniques against Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Salmonella typhi, Salmonella paratyphi A and Salmonella paratyphi B. They both showed significant activities against P. aeruginosa, S. typhi, S. paratyphi A and S. paratyphi B. [Copyright &y& Elsevier]