The Experts below are selected from a list of 12075 Experts worldwide ranked by ideXlab platform
Hirokazu Kawagishi - One of the best experts on this subject based on the ideXlab platform.
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Hydroxylation of bisphenol A by hyper lignin-degrading fungus Phanerochaete sordida YK-624 under non-ligninolytic condition.
Chemosphere, 2013Co-Authors: Jianqiao Wang, Hirofumi Hirai, Yotaro Yamamoto, Toshinobu Tokumoto, Jing Dong, Peter Thomas, Ryoko Yamamoto, Hirokazu KawagishiAbstract:Bisphenol A (BPA) is one of the representative compounds of the endocrine disrupting compounds group and the highest volume chemicals produced worldwide. As a result, BPA is often detected in many soil and water environments. In this study, we demonstrated the transformation of BPA from liquid cultures inoculated with hyper lignin-degrading fungus Phanerochaete sordida YK-624. Under non-ligninolytic condition, approximately 80% of BPA was eliminated after 7d of incubation. High-resolution electrospray ionization mass spectra and nuclear magnetic resonance analyses of a metabolite isolated from the culture supernatant suggested that BPA was metabolized to hydroxy-BPA, 4-(2-(4-hydroxyphenyl)propan-2-yl)benzene-1,2-diol, which has a much lower estrogenic activity than BPA. In addition, we investigated the effect of the Cytochrome P450 Inhibitor piperonyl butoxide (PB) on the hydroxylation of BPA, markedly lower transformation activity of BPA was observed in cultures containing PB. These results suggest that Cytochrome P450 plays an important role in the hydroxylation of BPA by P. sordida YK-624 under non-ligninolytic condition.
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Biotransformation of acetamiprid by the white-rot fungus Phanerochaete sordida YK-624.
Applied microbiology and biotechnology, 2011Co-Authors: Jianqiao Wang, Hirofumi Hirai, Hirokazu KawagishiAbstract:Acetamiprid (ACE) belongs to the neonicotinoid class of systemic broad-spectrum insecticides, which are the most highly effective and largest-selling insecticides worldwide for crop protection. As neonicotinoid insecticides persist in crops, biotransformation of these insecticides represents a promising approach for improving the safety of foods. Here, the elimination of ACE from a liquid medium by the white-rot fungus Phanerochaete sordida YK-624 was examined. Under ligninolytic and non-ligninolytic conditions, 45% and 30% of ACE were eliminated, respectively, after 15 days of incubation. High-resolution electrospray ionization mass spectra and nuclear magnetic resonance analyses of a metabolite identified in the culture supernatant suggested that ACE was N-demethylated to (E)-N (1)-[(6-chloro-3-pyridyl)-methyl]-N (2)-cyano-acetamidine, which has a much lower toxicity than ACE. In addition, we investigated the effect of the Cytochrome P450 Inhibitor piperonyl butoxide (PB) on the elimination of ACE. The elimination rate of ACE by P. sordida YK-624 was markedly reduced by the addition of either 0.01 or 0.1 mM PB to the culture medium. These results suggest that Cytochrome P450 plays an important role in the N-demethylation of ACE by P. sordida YK-624.
Stephen B Powles - One of the best experts on this subject based on the ideXlab platform.
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non target site resistance to pds inhibiting herbicides in a wild radish raphanus raphanistrum population
Pest Management Science, 2020Co-Authors: Huan Lu, Qin Yu, Mechelle J Owen, Stephen B PowlesAbstract:BACKGROUND: Diflufenican resistance has been reported in wild radish populations since 1998, but the resistance mechanisms have not been investigated. Recently, we identified a wild radish population (H2/10) from the Western Australian grain belt that is resistant (R) to the phytoene desaturase (PDS)-inhibiting herbicide diflufenican. RESULTS: Dose-response results showed this R population is 4.9-fold more resistant than the susceptible (S) population based on the LD50 R/S ratio. In addition, the R population also exhibits cross-resistance to the PDS-inhibiting herbicide fluridone. The Cytochrome P450 Inhibitor malathion reversed diflufenican resistance and partially reversed fluridone resistance in the R population. The full coding sequences of the PDS gene were cloned from the S and R plants and there are natural variations in the PDS gene transcripts/alleles with no correlation to resistance. In addition, the R plants had a level of PDS gene expression that is not significantly different from the S plants. CONCLUSION: These results demonstrated that diflufenican resistance in this R wild radish population is likely due to non-target-site based enhanced herbicide metabolism involving Cytochrome P450s. © 2019 Society of Chemical Industry.
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recurrent selection with reduced 2 4 d amine doses results in the rapid evolution of 2 4 d herbicide resistance in wild radish raphanus raphanistrum l
Pest Management Science, 2016Co-Authors: Michael B. Ashworth, Michael J Walsh, Ken Flower, Stephen B PowlesAbstract:BACKGROUND When used at effective doses, weed resistance to auxinic herbicides has been slow to evolve when compared with other modes of action. Here we report the evolutionary response of a herbicide-susceptible population of wild radish (Raphanus raphanistrum L.) and confirm that sublethal doses of 2,4-dichlorophenoxyacetic acid (2,4-D) amine can lead to the rapid evolution of 2,4-D resistance and cross-resistance to acetolactate synthase (ALS)-inhibiting herbicides. RESULTS Following four generations of 2,4-D selection, the progeny of a herbicide-susceptible wild radish population evolved 2,4-D resistance, increasing the LD50 from 16 to 138 g ha−1. Along with 2,4-D resistance, cross-resistance to the ALS-inhibiting herbicides metosulam (4.0-fold) and chlorsulfuron (4.5-fold) was evident. Pretreatment of the 2,4-D-selected population with the Cytochrome P450 Inhibitor malathion restored chlorsulfuron to full efficacy, indicating that cross-resistance to chlorsulfuron was likely due to P450-catalysed enhanced rates of herbicide metabolism. CONCLUSION This study is the first to confirm the rapid evolution of auxinic herbicide resistance through the use of low doses of 2,4-D and serves as a reminder that 2,4-D must always be used at highly effective doses. With the introduction of transgenic auxinic-herbicide-resistant crops in the Americas, there will be a marked increase in auxinic herbicide use and therefore the risk of resistance evolution. Auxinic herbicides should be used only at effective doses and with diversity if resistance is to remain a minimal issue. © 2016 Society of Chemical Industry
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distinct non target site mechanisms endow resistance to glyphosate accase and als inhibiting herbicides in multiple herbicide resistant lolium rigidum
Planta, 2009Co-Authors: Ibrahim Abdallah, Mechelle J Owen, Heping Han, Stephen B PowlesAbstract:This study investigates mechanisms of multiple resistance to glyphosate, acetyl-coenzyme A carboxylase (ACCase) and acetolactate synthase (ALS)-inhibiting herbicides in two Lolium rigidum populations from Australia. When treated with glyphosate, susceptible (S) plants accumulated 4- to 6-fold more shikimic acid than resistant (R) plants. The resistant plants did not have the known glyphosate resistance endowing mutation of 5-enolpyruvylshikimate-3 phosphate synthase (EPSPS) at Pro-106, nor was there over-expression of EPSPS in either of the R populations. However, [14C]-glyphosate translocation experiments showed that the R plants in both populations have altered glyphosate translocation patterns compared to the S plants. The R plants showed much less glyphosate translocation to untreated young leaves, but more to the treated leaf tip, than did the S plants. Sequencing of the carboxyl transferase domain of the plastidic ACCase gene revealed no resistance endowing amino acid substitutions in the two R populations, and the ALS in vitro inhibition assay demonstrated herbicide-sensitive ALS in the ALS R population (WALR70). By using the Cytochrome P450 Inhibitor malathion and amitrole with ALS and ACCase herbicides, respectively, we showed that malathion reverses chlorsulfuron resistance and amitrole reverses diclofop resistance in the R population examined. Therefore, we conclude that multiple glyphosate, ACCase and ALS herbicide resistance in the two R populations is due to the presence of distinct non-target site based resistance mechanisms for each herbicide. Glyphosate resistance is due to reduced rates of glyphosate translocation, and resistance to ACCase and ALS herbicides is likely due to enhanced herbicide metabolism involving different Cytochrome P450 enzymes.
Paul Workman - One of the best experts on this subject based on the ideXlab platform.
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the role of Cytochrome P450 and Cytochrome P450 reductase in the reductive bioactivation of the novel benzotriazine di n oxide hypoxic cytotoxin 3 amino l 2 4 benzotriazine l 4 dioxide sr 4233 win 59075 by mouse liver
Biochemical Pharmacology, 1992Co-Authors: Michael I Walton, C R Wolf, Paul WorkmanAbstract:Abstract SR 4233 or WIN 59075 (3-amino-1,2,4-benzotriazine-1,4-dioxide) is a novel and highly selective hypoxic cell cytotoxin requiring reductive bioactivation for its impressive antitumour effects. Expression of appropriate reductases will contribute to therapeutic selectivity. Here we provide more detailed information on the role of Cytochrome P450 and Cytochrome P450 reductase in SR 4233 reduction by mouse liver microsomes. Reduction of SR 4233 to the mono- N -oxide SR 4317 (3-amino-1,2, 4-benzotriazine-l-oxide) is NADPH. enzyme and hypoxia dependent. An Inhibitory antibody to Cytochrome P450 reductase decreased the microsomal SR 4233 reduction rate by around 20%. Moreover, studies with purified rat Cytochrome P450 reductase showed unequivocally that this enzyme was able to catalyse SR 4233 reduction at a rate of 20–30% of that for microsomes with equivalent P450 reductase activity. Exposure to the specific Cytochrome P450 Inhibitor carbon monoxide (CO) inhibited microsomal reduction by around 70% and CO plus reductase antibody blocked essentially all activity. Additional confirmation of Cytochrome P450 involvement was provided by the use of other P450 ligands: β- diethylaminoethyl diphenylpropylacetate hydrochloride gave a slight stimulation while aminopyrine, n - octylamine and 2,4-dichloro-6-phenylphenoxyethylamine were Inhibitory. Induction of SR 4233 reduction was seen with phenobarbitone, pregnenalone-16-a-carbonitrile and β-napthoflavone, suggesting that Cytochrome P450 subfamilies IIB. IIC and IIIA may be involved. Since Cytochrome P450 and P450 reductase catalyse roughly 70 and 30%. of mouse liver microsomal SR 4233 reduction respectively, we propose that expression of these and other reductases in normal and tumour tissue is likely to be a major factor governing the toxicity and antitumour activity of the drug.
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The role of Cytochrome P450 and Cytochrome P450 reductase in the reductive bioactivation of the novel benzotriazine di-N-oxide hypoxic cytotoxin 3-amino-l,2,4-benzotriazine-l ,4-dioxide (SR 4233, WIN 59075) by mouse liver
Biochemical pharmacology, 1992Co-Authors: Michael I Walton, C R Wolf, Paul WorkmanAbstract:SR 4233 or WIN 59075 (3-amino-1,2,4-benzotriazine-1,4-dioxide) is a novel and highly selective hypoxic cell cytotoxin requiring reductive bioactivation for its impressive antitumour effects. Expression of appropriate reductases will contribute to therapeutic selectivity. Here we provide more detailed information on the role of Cytochrome P450 and Cytochrome P450 reductase in SR 4233 reduction by mouse liver microsomes. Reduction of SR 4233 to the mono-N-oxide SR 4317 (3-amino-1,2,4-benzotriazine-1-oxide) is NADPH, enzyme and hypoxia dependent. An Inhibitory antibody to Cytochrome P450 reductase decreased the microsomal SR 4233 reduction rate by around 20%. Moreover, studies with purified rat Cytochrome P450 reductase showed unequivocally that this enzyme was able to catalyse SR 4233 reduction at a rate of 20-30% of that for microsomes with equivalent P450 reductase activity. Exposure to the specific Cytochrome P450 Inhibitor carbon monoxide (CO) inhibited microsomal reduction by around 70% and CO plus reductase antibody blocked essentially all activity. Additional confirmation of Cytochrome P450 involvement was provided by the use of other P450 ligands: beta-diethylaminoethyl diphenylpropylacetate hydrochloride gave a slight stimulation while aminopyrine, n-octylamine and 2,4-dichloro-6-phenylphenoxyethylamine were Inhibitory. Induction of SR 4233 reduction was seen with phenobarbitone, pregnenalone-16-alpha-carbonitrile and beta-napthoflavone, suggesting that Cytochrome P450 subfamilies IIB, IIC and IIIA may be involved. Since Cytochrome P450 and P450 reductase catalyse roughly 70 and 30%, of mouse liver microsomal SR 4233 reduction respectively, we propose that expression of these and other reductases in normal and tumour tissue is likely to be a major factor governing the toxicity and antitumour activity of the drug.
Jianqiao Wang - One of the best experts on this subject based on the ideXlab platform.
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Hydroxylation of bisphenol A by hyper lignin-degrading fungus Phanerochaete sordida YK-624 under non-ligninolytic condition.
Chemosphere, 2013Co-Authors: Jianqiao Wang, Hirofumi Hirai, Yotaro Yamamoto, Toshinobu Tokumoto, Jing Dong, Peter Thomas, Ryoko Yamamoto, Hirokazu KawagishiAbstract:Bisphenol A (BPA) is one of the representative compounds of the endocrine disrupting compounds group and the highest volume chemicals produced worldwide. As a result, BPA is often detected in many soil and water environments. In this study, we demonstrated the transformation of BPA from liquid cultures inoculated with hyper lignin-degrading fungus Phanerochaete sordida YK-624. Under non-ligninolytic condition, approximately 80% of BPA was eliminated after 7d of incubation. High-resolution electrospray ionization mass spectra and nuclear magnetic resonance analyses of a metabolite isolated from the culture supernatant suggested that BPA was metabolized to hydroxy-BPA, 4-(2-(4-hydroxyphenyl)propan-2-yl)benzene-1,2-diol, which has a much lower estrogenic activity than BPA. In addition, we investigated the effect of the Cytochrome P450 Inhibitor piperonyl butoxide (PB) on the hydroxylation of BPA, markedly lower transformation activity of BPA was observed in cultures containing PB. These results suggest that Cytochrome P450 plays an important role in the hydroxylation of BPA by P. sordida YK-624 under non-ligninolytic condition.
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Biotransformation of acetamiprid by the white-rot fungus Phanerochaete sordida YK-624.
Applied microbiology and biotechnology, 2011Co-Authors: Jianqiao Wang, Hirofumi Hirai, Hirokazu KawagishiAbstract:Acetamiprid (ACE) belongs to the neonicotinoid class of systemic broad-spectrum insecticides, which are the most highly effective and largest-selling insecticides worldwide for crop protection. As neonicotinoid insecticides persist in crops, biotransformation of these insecticides represents a promising approach for improving the safety of foods. Here, the elimination of ACE from a liquid medium by the white-rot fungus Phanerochaete sordida YK-624 was examined. Under ligninolytic and non-ligninolytic conditions, 45% and 30% of ACE were eliminated, respectively, after 15 days of incubation. High-resolution electrospray ionization mass spectra and nuclear magnetic resonance analyses of a metabolite identified in the culture supernatant suggested that ACE was N-demethylated to (E)-N (1)-[(6-chloro-3-pyridyl)-methyl]-N (2)-cyano-acetamidine, which has a much lower toxicity than ACE. In addition, we investigated the effect of the Cytochrome P450 Inhibitor piperonyl butoxide (PB) on the elimination of ACE. The elimination rate of ACE by P. sordida YK-624 was markedly reduced by the addition of either 0.01 or 0.1 mM PB to the culture medium. These results suggest that Cytochrome P450 plays an important role in the N-demethylation of ACE by P. sordida YK-624.
Ernest Marcourrea - One of the best experts on this subject based on the ideXlab platform.
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degradation of the antibiotics norfloxacin and ciprofloxacin by a white rot fungus and identification of degradation products
Bioresource Technology, 2011Co-Authors: Ailette Prieto, Monika Moder, Rosario Rodil, Lorenz Adrian, Ernest MarcourreaAbstract:Abstract More than 90% of the antibiotics ciprofloxacin (CIPRO) and norfloxacin (NOR) at 2 mg L −1 were degraded by Trametes versicolor after 7 days of incubation in malt extract liquid medium. In in vitro assays with purified laccase (16.7 nkat mL −1 ), an extracellular enzyme excreted constitutively by this fungus, 16% of CIPRO was removed after 20 h. The addition of the laccase mediator 2,2-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt led to 97.7% and 33.7% degradation of CIPRO and NOR, respectively. Inhibition of CIPRO and NOR degradation by the Cytochrome P450 Inhibitor 1-aminobenzotriazole suggests that the P450 system also plays a role in the degradation of the two antibiotics. Transformation products of CIPRO and NOR were monitored at different incubation times by triple-quadrupole and quadrupole time-of-flight mass spectrometry, and can be assigned to three different reaction pathways: (i) oxidation of the piperazinyl substituent, (ii) monohydroxylation, and (iii) formation of dimeric products.
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degradation of the drug sodium diclofenac by trametes versicolor pellets and identification of some intermediates by nmr
Journal of Hazardous Materials, 2010Co-Authors: Ernest Marcourrea, Miriam Pereztrujillo, Gloria Caminal, Carles Cruzmorato, Teresa VicentAbstract:Abstract Degradation of diclofenac sodium, a nonsteroidal anti-inflammatory drug widely found in the aquatic environment, was assessed using the white-rot fungus Trametes versicolor . Almost complete diclofenac removal (≥94%) occurred the first hour with T. versicolor pellets when the drug was added at relatively high (10 mg L −1 ) and environmentally relevant low (45 μg L −1 ) concentrations in a defined liquid medium. In vivo and in vitro experiments using the Cytochrome P450 Inhibitor 1-aminobenzotriazole and purified laccase, respectively, suggested at least two different mechanisms employed by T. versicolor to initiate diclofenac degradation. Two hydroxylated metabolites, 4′-hydroxydiclofenac and 5-hydroxydiclofenac, were structurally elucidated by nuclear magnetic resonance as degradation intermediates in fungal cultures spiked with diclofenac. Both parent compound and intermediates disappeared after 24 h leading to a decrease in ecotoxicity calculated by the Microtox test. Laccase-catalyzed transformation of diclofenac led to the formation of 4-(2,6-dichlorophenylamino)-1,3-benzenedimethanol, which was not detected in in vivo experiments probably due to the low laccase activity levels observed through the first hours of incubation.
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biodegradation of the analgesic naproxen by trametes versicolor and identification of intermediates using hplc dad ms and nmr
Bioresource Technology, 2010Co-Authors: Ernest Marcourrea, Miriam Pereztrujillo, Paqui Blanquez, Teresa Vicent, Gloria CaminalAbstract:Abstract The white-rot fungus Trametes vesicolor degraded naproxen (10 mg L −1 ) in a liquid medium to non-detectable levels after 6 h. When naproxen was added in the range of concentrations typically found in the environment (55 μg L −1 ), it was almost completely degraded (95%) after 5 h. In vitro degradation experiments with purified laccase and purified laccase plus mediator 1-hydroxybenzotriazol showed slight and almost complete naproxen degradation, respectively. A noticeable inhibition on naproxen degradation was also observed when the Cytochrome P450 Inhibitor 1-aminobenzotriazole was added to the fungal cultures. These data suggest that both enzymatic systems could play a role in naproxen degradation. 2-(6-hydroxynaphthalen-2-yl)propanoic acid and 1-(6-methoxynaphthalen-2-yl)ethanone were structurally elucidated by HPLC-DAD-MS and NMR as degradation intermediates of naproxen. After 6 h of incubation, both parent compound and intermediates disappeared from the medium. The non-toxicity of the treated medium was confirmed by Microtox test.
