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Article in Chinese | WPRIM | ID: wpr-878890


According to human carboxylesterase 2(hCE2) inhibitors reported in the literature, the pharmacophore model of hCE2 inhibitors was developed using HipHop module in Discovery Studio 2016. The optimized pharmacophore model, which was validated by test set, contained two hydrophobic, one hydrogen bond acceptor, and one aromatic ring features. Using the pharmacophore model established, 5 potential hCE2 inhibitors(CS-1,CS-2,CS-3,CS-6 and CS-8) were screened from 20 compounds isolated from the roots of Paeonia lactiflora, which were further confirmed in vitro, with the IC_(50) values of 5.04, 5.21, 5.95, 6.64 and 7.94 μmol·L~(-1), respectively. The results demonstrated that the pharmacophore model exerted excellent forecasting ability with high precision, which could be applied to screen novel hCE2 inhibitors from Chinese medicinal materials.

Carboxylesterase/metabolism , Humans , Hydrogen Bonding , Hydrophobic and Hydrophilic Interactions
Braz. j. microbiol ; 47(2): 327-336, Apr.-June 2016. tab, graf
Article in English | LILACS | ID: lil-780820


Abstract Diamondback moth (DBM), Plutella xylostella (Linnaeus), is a notorious pest of brassica crops worldwide and is resistant to all groups of insecticides. The insect system harbors diverse groups of microbiota, which in turn helps in enzymatic degradation of xenobiotic-like insecticides. The present study aimed to determine the diversity of gut microflora in DBM, quantify esterase activity and elucidate their possible role in degradation of indoxacarb. We screened 11 geographic populations of DBM in India and analyzed them for bacterial diversity. The culturable gut bacterial flora underwent molecular characterization with 16S rRNA. We obtained 25 bacterial isolates from larvae (n = 13) and adults (n = 12) of DBM. In larval gut isolates, gammaproteobacteria was the most abundant (76%), followed by bacilli (15.4%). Molecular characterization placed adult gut bacterial strains into three major classes based on abundance: gammaproteobacteria (66%), bacilli (16.7%) and flavobacteria (16.7%). Esterase activity from 19 gut bacterial isolates ranged from 0.072 to 2.32 µmol/min/mg protein. Esterase bands were observed in 15 bacterial strains and the banding pattern differed in Bacillus cereus – KC985225 and Pantoea agglomerans – KC985229. The bands were characterized as carboxylesterase with profenofos used as an inhibitor. Minimal media study showed that B. cereus degraded indoxacarb up to 20%, so it could use indoxacarb for metabolism and growth. Furthermore, esterase activity was greater with minimal media than control media: 1.87 versus 0.26 µmol/min/mg protein. Apart from the insect esterases, bacterial carboxylesterase may aid in the degradation of insecticides in DBM.

Animals , Male , Female , Oxazines/metabolism , Bacteria/enzymology , Carboxylesterase/metabolism , Esterases/metabolism , Gastrointestinal Microbiome , Insecticides/metabolism , Moths/microbiology , Phylogeny , Bacteria/isolation & purification , Bacteria/classification , Bacteria/genetics , Gastrointestinal Tract/microbiology , Carboxylesterase/genetics , Esterases/genetics , India
Braz. j. microbiol ; 46(2): 425-432, Apr-Jun/2015. tab, graf
Article in English | LILACS | ID: lil-749712


The strain JPL-2, capable of degrading fenoxaprop-P-ethyl (FE), was isolated from the soil of a wheat field and identified as Rhodococcus ruber. This strain could utilize FE as its sole carbon source and degrade 94.6% of 100 mg L−1 FE in 54 h. Strain JPL-2 could also degrade other aryloxyphenoxy propanoate (AOPP) herbicides. The initial step of the degradation pathway is to hydrolyze the carboxylic acid ester bond. A novel esterase gene feh, encoding the FE-hydrolyzing carboxylesterase (FeH) responsible for this initial step, was cloned from strain JPL-2. Its molecular mass was approximately 39 kDa, and the catalytic efficiency of FeH followed the order of FE > quizalofop-P-ethyl > clodinafop-propargyl > cyhalofop-butyl > fluazifop-P-butyl > haloxyfop-P-methyl > diclofop-methy, which indicated that the chain length of the alcohol moiety strongly affected the hydrolysis activity of the FeH toward AOPP herbicides.

Carboxylesterase/genetics , Carboxylesterase/metabolism , Herbicides/metabolism , Oxazoles/metabolism , Propionates/metabolism , Rhodococcus/isolation & purification , Rhodococcus/metabolism , Biotransformation , Cloning, Molecular , Cluster Analysis , Carboxylesterase/chemistry , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Molecular Sequence Data , Molecular Weight , Phylogeny , /genetics , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Rhodococcus/enzymology , Rhodococcus/genetics , Sequence Analysis, DNA , Soil Microbiology , Substrate Specificity , Triticum/growth & development