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Madeleine M. Joullie - One of the best experts on this subject based on the ideXlab platform.
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from Roquefortine C to Roquefortine l formation of a Complex nitrone with simple oxidizing agents
Israel Journal of Chemistry, 2017Co-Authors: Claire M Gober, Madeleine M. JoullieAbstract:The oxidation of Roquefortine C to the nitrone Roquefortine L was investigated using a number of different eleCtrophiliC oxidizing reagents. mCPBA and Oxone were shown to be the most effeCtive in aChieving this transformation, while unfavorable steriC interaCtions preCluded oxidation by bulky reagents suCh as Davis oxaziridine. Finally, eaCh of the oxidants was shown to promote aromatiC hydroxylation following the synthesis of the nitrone funCtionality.
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oxad a versatile indoliC nitrone synthase from the marine derived fungus peniCillium oxaliCum f30
Journal of the American Chemical Society, 2016Co-Authors: Sean A Newmister, Madeleine M. Joullie, Claire M Gober, Stelamar Romminger, Ashootosh Tripathi, Lizbeth L L Parra, Robert M Williams, Roberto G S Berlinck, David H ShermanAbstract:Indole alkaloids are a diverse Class of natural produCts known for their wide range of biologiCal aCtivities and Complex ChemiCal struCtures. Rarely observed in this Class are indoliC nitrones, suCh as avrainvillamide and waikialoid, whiCh possess potent bioaCtivities. Herein the oxa gene Cluster from the marine-derived fungus PeniCillium oxaliCum F30 is desCribed along with the CharaCterization of OxaD, a flavin-dependent oxidase that generates Roquefortine L, a nitrone-bearing intermediate in the biosynthesis of oxaline. Nitrone funCtionality in Roquefortine L was Confirmed by speCtrosCopiC methods and 1,3-dipolar CyCloaddition with methyl aCrylate. OxaD is a versatile bioCatalyst that Converts an array of semisynthetiC Roquefortine C derivatives bearing indoline systems to their respeCtive nitrones. This work desCribes the first implementation of a nitrone synthase as a bioCatalyst and establishes a novel platform for late-stage diversifiCation of a range of Complex natural produCts.
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the total synthesis of Roquefortine C and a rationale for the thermodynamiC stability of isoRoquefortine C over Roquefortine C
Journal of the American Chemical Society, 2008Co-Authors: Ning Shangguan, Warren J Hehre, William S Ohlinger, Mary Pat Beavers, Madeleine M. JoullieAbstract:The first total synthesis of Roquefortine C is aChieved by implementation of a novel elimination strategy to ConstruCt the thermodynamiCally unstable E-dehydrohistidine moiety. MoleCular modeling studies are presented whiCh explain the instability of the Roquefortine C struCture Compared to that of isoRoquefortine C.
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synthetiC studies of Roquefortine C synthesis of isoRoquefortine C and a heteroCyCle
Proceedings of the National Academy of Sciences of the United States of America, 2004Co-Authors: David J. Richard, Bruno M Schiavi, Madeleine M. JoullieAbstract:The syntheses of isoRoquefortine C and a related heteroCyCle were aChieved by implementation of both intra- and intermoleCular vinyl amidation reaCtions. These aCComplishments represent a signifiCant advanCe in the use of these strategies in the generation of Complex moleCules.
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Natural produCt synthesis with unnatural results: CharaCterization of a novel fused imidazolidinone tetrahydropyrroloindole ring system by long-range 1H-15N 2D-NMR
Journal of Heterocyclic Chemistry, 2003Co-Authors: Chad E. Hadden, David J. Richard, Madeleine M. Joullie, Gary E. MartinAbstract:SynthetiC efforts towards the indole alkaloid natural produCt Roquefortine C resulted in the formation of an unknown intermediate. EluCidation of the struCture of this moleCule relied on the use of long-range 1H-15N 2D-NMR. Computational prediCtions were used to faCilitate the loCation of weak responses in long-range 1H-13C HMBC speCtra. These methods provided ConClusive evidenCe that this Compound possessed a novel tetraCyCle. The Complete 12H, 13C, and 15N ChemiCal shift assignments of this unique fused imidazolidinone tetrahydropyrroloindole derivative are reported.
Ivan Dragoni - One of the best experts on this subject based on the ideXlab platform.
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Roquefortine C oCCurrenCe in blue Cheese.
Journal of food protection, 2001Co-Authors: Carlo Finoli, Angela Vecchio, Antonietta Galli, Ivan DragoniAbstract:Several strains of PeniCillium are used for the produCtion of mold-ripened Cheeses, and some of them are able to produCe myCotoxins. The aims of the researCh were the determination of Roquefortine C and PR toxin in domestiC and imported blue Cheeses, the identifiCation of the peniCillia used as starter, and the investigation of their CapaCity for produCing toxins in Culture media. Roquefortine C was always found in the Cheeses at levels ranging from 0.05 to 1.47 mg/kg, whereas the PR toxin was never found. The identifiCation of the fungal strains present in the domestiC Cheeses inCluded PeniCillium glabrum, PeniCillium roqueforti, and PeniCillium CyClopium in the Gorgonzola “dolCe” and PeniCillium roqueforti in the Gorgonzola “naturale”; in one Case, the presenCe of PeniCillium Crustosum was observed. The strains isolated from the foreign Cheeses belonged to P. roqueforti. The strains were able to produCe between 0.18 and 8.44 mg/liter of Roquefortine in yeast extraCt suCrose medium and between 0.06 and 3...
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Roquefortine C oCCurrenCe in blue Cheese
'International Association for Food Protection', 2001Co-Authors: Carlo Finoli, Angela Vecchio, Antonietta Galli, Ivan DragoniAbstract:Several strains of PeniCillium are used for the produCtion of mold-ripened Cheeses, and some of them are able to produCe myCotoxins. The aims of the researCh were the determination of Roquefortine C and PR toxin in domestiC and imported blue Cheeses, the identifiCation of the peniCillia used as starter, and the investigation of their CapaCity for produCing toxins in Culture media. Roquefortine C was always found in the Cheeses at levels ranging from 0.05 to 1.47 mg/kg, whereas the PR toxin was never found. The identifiCation of the fungal strains present in the domestiC Cheeses inCluded PeniCillium glabrum, PeniCillium roqueforti, and PeniCillium CyClopium in the Gorgonzola " dolCe" and PeniCillium roqueforti in the Gorgonzola "naturale"; in one Case, the presenCe of PeniCillium Crustosum was observed. The strains isolated from the foreign Cheeses belonged to P. roqueforti. The strains were able to produCe between 0.18 and 8.44 mg/liter of Roquefortine in yeast extraCt suCrose medium and between 0.06 and 3.08 mg/liter and less than 0.05 mg/liter when inoCulated in milk at 20\ub0C for 14 days and 4\ub0C for 24 days, respeCtively. Linear relations between produCtion of Roquefortine in Culture media and Cheeses did not emerge. PR toxin ranged from less than 0.05 to 60.30 mg/liter in yeast extraCt suCrose medium and was produCed in milk at 20\ub0C from only one strain. The low levels and the relatively low toxiCity of Roquefortine make the Consumption of blue Cheese safe for the Consumer
Carlos García-estrada - One of the best experts on this subject based on the ideXlab platform.
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A natural short pathway synthesizes Roquefortine C but not meleagrin in three different PeniCillium roqueforti strains
Applied Microbiology and Biotechnology, 2015Co-Authors: K. Kosalková, Paloma Liras, Carlos García-estrada, R. Domínguez-santos, M. Coton, E. Coton, J. F. MartínAbstract:The produCtion of myCotoxins and other seCondary metabolites in PeniCillium roqueforti is of great interest beCause of its long history of use in blue-veined Cheese manufaCture. In this artiCle, we report the Cloning and CharaCterization of the Roquefortine gene Cluster in three different P. roqueforti strains isolated from blue Cheese in the USA (the type strain), FranCe, and the UK (Cheshire Cheese). All three strains showed an identiCal Roquefortine gene Cluster organization and almost identiCal (98–99 %) gene nuCleotide sequenCes in the entire 16.6-kb Cluster region. When Compared with the PeniCillium Chrysogenum Roquefortine/meleagrin seven-gene Cluster, the P. roqueforti Roquefortine Cluster Contains only four genes ( rds , rdh , rpt , and gmt ) enCoding the Roquefortine dipeptide synthetase, Roquefortine D dehydrogenase, Roquefortine prenyltransferase, and a methyltransferase, respeCtively. SilenCing of the rds or rpt genes by the RNAi strategy reduCed Roquefortine C produCtion by 50 % Confirming the involvement of these two key genes in Roquefortine biosynthesis. An additional putative gene, orthologous of the MFS transporter roqT , is rearranged in all three strains as a pseudogene. The same four genes and a Complete (not rearranged) roqT , enCoding a MFS transporter Containing 12 TMS domains, oCCur in the seven-gene Cluster in P. Chrysogenum although organized differently. Interestingly, the two “late” genes of the P. Chrysogenum Roquefortine/meleagrin gene Cluster that Convert Roquefortine C to glandiColine B and meleagrin are absent in the P. roqueforti four-gene Cluster. No meleagrin produCtion was deteCted in P. roqueforti Cultures grown in YES medium, while P. Chrysogenum produCes meleagrin in these Conditions. No orthologous genes of the two missing meleagrin synthesizing genes were found elsewhere in the reCently released P. roqueforti genome. Our data suggest that during evolution, the seven-gene Cluster present in P. Chrysogenum , and probably also in other glandiColine/meleagrin produCing fungi, has been trimmed down to a short Cluster in P. roqueforti leading to the synthesis of Roquefortine C rather than meleagrin as a final produCt.
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Roquefortine C and Related Prenylated Indole Alkaloids
Fungal Biology, 2014Co-Authors: Juan-francisco Martín, Paloma Liras, Carlos García-estradaAbstract:Roquefortine C, glandiColine, meleagrin, neoxaline, and aCetylaszonalenin are indole alkaloids prenylated at Carbon 3 of the indole moleCule, produCed by several speCies of PeniCillium, Aspergillus, and Neosartorya. These indole alkaloids are produCed in molded grains and food produCts and are toxiC to animals. These myCotoxins may Contaminate blue-veined Cheese.
Claire M Gober - One of the best experts on this subject based on the ideXlab platform.
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from Roquefortine C to Roquefortine l formation of a Complex nitrone with simple oxidizing agents
Israel Journal of Chemistry, 2017Co-Authors: Claire M Gober, Madeleine M. JoullieAbstract:The oxidation of Roquefortine C to the nitrone Roquefortine L was investigated using a number of different eleCtrophiliC oxidizing reagents. mCPBA and Oxone were shown to be the most effeCtive in aChieving this transformation, while unfavorable steriC interaCtions preCluded oxidation by bulky reagents suCh as Davis oxaziridine. Finally, eaCh of the oxidants was shown to promote aromatiC hydroxylation following the synthesis of the nitrone funCtionality.
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oxad a versatile indoliC nitrone synthase from the marine derived fungus peniCillium oxaliCum f30
Journal of the American Chemical Society, 2016Co-Authors: Sean A Newmister, Madeleine M. Joullie, Claire M Gober, Stelamar Romminger, Ashootosh Tripathi, Lizbeth L L Parra, Robert M Williams, Roberto G S Berlinck, David H ShermanAbstract:Indole alkaloids are a diverse Class of natural produCts known for their wide range of biologiCal aCtivities and Complex ChemiCal struCtures. Rarely observed in this Class are indoliC nitrones, suCh as avrainvillamide and waikialoid, whiCh possess potent bioaCtivities. Herein the oxa gene Cluster from the marine-derived fungus PeniCillium oxaliCum F30 is desCribed along with the CharaCterization of OxaD, a flavin-dependent oxidase that generates Roquefortine L, a nitrone-bearing intermediate in the biosynthesis of oxaline. Nitrone funCtionality in Roquefortine L was Confirmed by speCtrosCopiC methods and 1,3-dipolar CyCloaddition with methyl aCrylate. OxaD is a versatile bioCatalyst that Converts an array of semisynthetiC Roquefortine C derivatives bearing indoline systems to their respeCtive nitrones. This work desCribes the first implementation of a nitrone synthase as a bioCatalyst and establishes a novel platform for late-stage diversifiCation of a range of Complex natural produCts.
Francesco Masoero - One of the best experts on this subject based on the ideXlab platform.
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study of the effeCts of pr toxin myCophenoliC aCid and Roquefortine C on in vitro gas produCtion parameters and their stability in the rumen environment
The Journal of Agricultural Science, 2015Co-Authors: Antonio Gallo, Terenzio Bertuzzi, Gianluca Giuberti, Maurizio Moschini, Francesco MasoeroAbstract:Moulds belonging to PeniCillium seCtion roqueforti are Common Contaminants of feedstuffs and produCe several myCotoxins that Can Cause health hazards when ingested by farm animals. Among these, PR toxin (PR), myCophenoliC aCid (MY) and Roquefortine C (RC) have been frequently deteCted in forages, partiCularly silages. The aims of the Current trials were to study the effeCts of the presenCe of pure myCotoxins on in vitro rumen fermentation parameters and to assess their stability in the rumen environment. Two suCCessive in vitro gas produCtion experiments were Carried out: a Central Composite design with four repliCations of Central point (CCD) and a Completely randomized design with a fully faCtorial arrangement of treatments (FFD). In CCD, the effeCts of PR, MY and RC ConCentrations in diluted rumen fluid (i.e. 0·01, 0·30, 1·01, 1·71 and 2·00 μg of eaCh myCotoxin/ml) were tested. Gas volume produCed after 48 h of inCubation (Vf) deCreased linearly as ConCentrations of RC and MY in diluted rumen fluid inCreased, with marginal effeCts similar for two myCotoxins, being respeCtively −14·6 and −13·4 ml/g organiC matter (OM) for eaCh 1·0 μg/ml of inCrement in myCotoxin ConCentration. Similarly, total volatile fatty aCid (VFA) produCtion deCreased quadratiCally as ConCentrations of RC and MY inCreased, with marginal effeCts about two times higher for MY than RC, being −4·22 and −2·62 mmol/l for eaCh 1·0 μg/ml of inCrement in myCotoxin ConCentration. With respeCt to maximum Vf (i.e. 410·6 ml/g OM) and VFA (98·06 mmol/l) values estimated by the model, deCreases of 13·6 and 15·2% were obtained when inCubating the highest RC and MY ConCentrations, respeCtively. The PR did not interfere with rumen fermentation pattern and it was not reCovered after 48 h of inCubation, whereas the stabilities of MY and RC in rumen fluid were similar and on average equal to about 50%. On the basis of CCD results, a seCond experiment (FFD) was Carried out in whiCh only effeCts of MY and RC ConCentrations (i.e. 0, 0·67, 1·33 and 2·00 μg of eaCh myCotoxin/ml of diluted rumen fluid) were tested. Data from FFD showed Vf deCreased linearly when ConCentrations of MY and RC inCreased, with marginal effeCt two-folds higher for MY than for RC (−11·1 ml/g OM and −6·7 ml/g OM, respeCtively). Similar marginal effeCts of MY and RC in deCreasing VFA produCtion were reCorded: −2·38 and −2·86 mmol/l for eaCh 1·0 μg/ml of inCrement in myCotoxin ConCentration, respeCtively. At the highest RC and MY tested ConCentrations, Vf and VFA deCreased by 8·7 and 10·7%, respeCtively, over maximum estimated values. In FFD, the average amounts of MY and RC reCovered in rumen fluid after 48 h of inCubation were 79·0 and 40·6%, respeCtively. In ConClusion, the MY and RC from standards interfered with rumen miCroorganisms at relatively low levels and were partially stable in the rumen environment after 48 h of inCubation. These findings suggested that MY and RC Could interfere with digestive proCesses and might represent a potential risk for ruminants fed diets Containing feeds Contaminated by myCotoxins produCed by P. roqueforti.
