The Experts below are selected from a list of 969 Experts worldwide ranked by ideXlab platform
Jie-kun Xu - One of the best experts on this subject based on the ideXlab platform.
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An unusual racemic C12-norabietane Diterpene and a new abietane Diterpene Alkaloid from Salvia miltiorrhiza Bunge
Fitoterapia, 2017Co-Authors: Jun He, Bing-zhi Ma, Xiao Xue Wang, Wei-ku Zhang, Jia Zhang, Jie-kun XuAbstract:Abstract A rare C12-norabietane Diterpene racemate (1) and a new abietane Diterpene Alkaloid (2) were isolated from the roots of Salvia miltiorrhiza Bunge. Their structures were established by comprehensive spectroscopic analyses, and 1 was successfully resolved by chiral HPLC, demonstrating that 1 is racemic. The absolute configurations of 1a [(+)-miltiorolide A], 1b [(−)-miltiorolide A], and 2 were determined using TDDFT-ECD calculations. 1a and 1b are the first examples of enantiomeric C12-norabietane Diterpenes featuring an isobutylene with a tetrahydronaphthalene-butyrolactone ring system. The cytotoxic activities of the isolates (1 and 2) were evaluated against three human cancer cell lines BEL-7402, HT-29 and PANC-28. A plausible biogenetic pathway of 1 was also proposed.
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An unusual racemic C12-norabietane Diterpene and a new abietane Diterpene Alkaloid from Salvia miltiorrhiza Bunge
Fitoterapia, 2017Co-Authors: Jun He, Bing-zhi Ma, Xiao Xue Wang, Wei-ku Zhang, Jia Zhang, Jie-kun XuAbstract:Abstract A rare C12-norabietane Diterpene racemate (1) and a new abietane Diterpene Alkaloid (2) were isolated from the roots of Salvia miltiorrhiza Bunge. Their structures were established by comprehensive spectroscopic analyses, and 1 was successfully resolved by chiral HPLC, demonstrating that 1 is racemic. The absolute configurations of 1a [(+)-miltiorolide A], 1b [(−)-miltiorolide A], and 2 were determined using TDDFT-ECD calculations. 1a and 1b are the first examples of enantiomeric C12-norabietane Diterpenes featuring an isobutylene with a tetrahydronaphthalene-butyrolactone ring system. The cytotoxic activities of the isolates (1 and 2) were evaluated against three human cancer cell lines BEL-7402, HT-29 and PANC-28. A plausible biogenetic pathway of 1 was also proposed.
Ewald Usleber - One of the best experts on this subject based on the ideXlab platform.
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a rapid screening method for the tremorgenic indole Diterpene Alkaloid mycotoxin paxilline in beer
Food Analytical Methods, 2018Co-Authors: Julia I Bauer, Gerd Hamscher, Madeleine Gross, Ewald UsleberAbstract:The tremorgenic paxilline (PAX), an indole-Diterpene Alkaloid mycotoxin, was recently detected as a natural contaminant of ergot of barley and rye. To check the possibility of a transfer of this mycotoxin into beer, a rapid and sensitive immunochemical method for the analysis of PAX in commercial bottled beer was developed. A straightforward sample preparation procedure could be established, including degassing, pH adjustment, optional filtering, and finally a 1:5 dilution with a methanolic phosphate-buffered saline solution. Analysis of PAX was performed by a competitive indirect enzyme immunoassay (EIA). The detection limit at a cut-off value of 80% B/B0 of the EIA standard curve was evaluated by analysis of spiked beer. PAX at levels of 3 μg/L and 5 μg/L yielded 69% and 100% positive results, therefore the detection limit in beer was at 5 μg/L. Recoveries of PAX at levels of 5–20 μg/L were 88–97%, coefficients of variation were 17–22%. With these characteristics, the EIA was considered to be a suitable screening method for PAX in beer. A survey of bottled beer from the German market was conducted which included 38 samples of domestic and international brands, the latter containing various flavoring ingredients. All samples were clearly negative for PAX, which indicates that this toxin is not a relevant contaminant in beer.
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Detection of the tremorgenic mycotoxin paxilline and its desoxy analog in ergot of rye and barley: a new class of mycotoxins added to an old problem
Analytical and Bioanalytical Chemistry, 2017Co-Authors: Julia I Bauer, Gerd Hamscher, Sandra Wegner, Heike Hausmann, Benedikt Cramer, Madeleine Gross, Ewald UsleberAbstract:A newly developed enzyme immunoassay (EIA) for the detection of the tremorgenic indole-Diterpene Alkaloid paxilline (PAX) and closely related analogs was used to analyze ergot sclerotia collected from rye and barley fields. The mean EIA standard curve detection limit was 0.47 ± 0.14 ng/mL; relative cross-reactivity of toxin standard solutions was found for 11-hydroxy-paspaline (terpendole E, 1.1%) but not for lolitrem B or ergot Alkaloids. Sclerotia from all fields were positive in the PAX-EIA at concentration levels of 620 ± 200 and 160 ± 37 μg/kg in ergot of rye and 130 ± 47 μg/kg in ergot of barley. Confirmatory analyses of sclerotia by liquid chromatography-tandem mass spectrometric detection identified PAX and its analog 13-desoxypaxilline. To the best of our knowledge, this is the first report on the natural occurrence of tremorgenic indole-Diterpene Alkaloid mycotoxins in ergot sclerotia from rye and barley. Along with details on the analytical methodology developed in this study, particularly PAX-antibody production, the relevance and implications of these findings for food and feed safety are discussed. Presence or absence of elevated levels of tremorgenic mycotoxins, along with the ergot Alkaloids, would help in explaining the difference between the two distinct manifestations of historic ergotism, the convulsive and the gangrenous form. Further method development for paxilline and other tremorgenic mycotoxins in cereals used for food and feed is a prerequisite for a comprehensive risk assessment, which seems to be necessary in light of the findings reported here. Paxilline in ergot of rye
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detection of the tremorgenic mycotoxin paxilline and its desoxy analog in ergot of rye and barley a new class of mycotoxins added to an old problem
Analytical and Bioanalytical Chemistry, 2017Co-Authors: Julia I Bauer, Gerd Hamscher, Sandra Wegner, Heike Hausmann, Benedikt Cramer, Madeleine Gross, Ewald UsleberAbstract:A newly developed enzyme immunoassay (EIA) for the detection of the tremorgenic indole-Diterpene Alkaloid paxilline (PAX) and closely related analogs was used to analyze ergot sclerotia collected from rye and barley fields. The mean EIA standard curve detection limit was 0.47 ± 0.14 ng/mL; relative cross-reactivity of toxin standard solutions was found for 11-hydroxy-paspaline (terpendole E, 1.1%) but not for lolitrem B or ergot Alkaloids. Sclerotia from all fields were positive in the PAX-EIA at concentration levels of 620 ± 200 and 160 ± 37 μg/kg in ergot of rye and 130 ± 47 μg/kg in ergot of barley. Confirmatory analyses of sclerotia by liquid chromatography-tandem mass spectrometric detection identified PAX and its analog 13-desoxypaxilline. To the best of our knowledge, this is the first report on the natural occurrence of tremorgenic indole-Diterpene Alkaloid mycotoxins in ergot sclerotia from rye and barley. Along with details on the analytical methodology developed in this study, particularly PAX-antibody production, the relevance and implications of these findings for food and feed safety are discussed. Presence or absence of elevated levels of tremorgenic mycotoxins, along with the ergot Alkaloids, would help in explaining the difference between the two distinct manifestations of historic ergotism, the convulsive and the gangrenous form. Further method development for paxilline and other tremorgenic mycotoxins in cereals used for food and feed is a prerequisite for a comprehensive risk assessment, which seems to be necessary in light of the findings reported here.
Jun He - One of the best experts on this subject based on the ideXlab platform.
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An unusual racemic C12-norabietane Diterpene and a new abietane Diterpene Alkaloid from Salvia miltiorrhiza Bunge
Fitoterapia, 2017Co-Authors: Jun He, Bing-zhi Ma, Xiao Xue Wang, Wei-ku Zhang, Jia Zhang, Jie-kun XuAbstract:Abstract A rare C12-norabietane Diterpene racemate (1) and a new abietane Diterpene Alkaloid (2) were isolated from the roots of Salvia miltiorrhiza Bunge. Their structures were established by comprehensive spectroscopic analyses, and 1 was successfully resolved by chiral HPLC, demonstrating that 1 is racemic. The absolute configurations of 1a [(+)-miltiorolide A], 1b [(−)-miltiorolide A], and 2 were determined using TDDFT-ECD calculations. 1a and 1b are the first examples of enantiomeric C12-norabietane Diterpenes featuring an isobutylene with a tetrahydronaphthalene-butyrolactone ring system. The cytotoxic activities of the isolates (1 and 2) were evaluated against three human cancer cell lines BEL-7402, HT-29 and PANC-28. A plausible biogenetic pathway of 1 was also proposed.
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An unusual racemic C12-norabietane Diterpene and a new abietane Diterpene Alkaloid from Salvia miltiorrhiza Bunge
Fitoterapia, 2017Co-Authors: Jun He, Bing-zhi Ma, Xiao Xue Wang, Wei-ku Zhang, Jia Zhang, Jie-kun XuAbstract:Abstract A rare C12-norabietane Diterpene racemate (1) and a new abietane Diterpene Alkaloid (2) were isolated from the roots of Salvia miltiorrhiza Bunge. Their structures were established by comprehensive spectroscopic analyses, and 1 was successfully resolved by chiral HPLC, demonstrating that 1 is racemic. The absolute configurations of 1a [(+)-miltiorolide A], 1b [(−)-miltiorolide A], and 2 were determined using TDDFT-ECD calculations. 1a and 1b are the first examples of enantiomeric C12-norabietane Diterpenes featuring an isobutylene with a tetrahydronaphthalene-butyrolactone ring system. The cytotoxic activities of the isolates (1 and 2) were evaluated against three human cancer cell lines BEL-7402, HT-29 and PANC-28. A plausible biogenetic pathway of 1 was also proposed.
Julia I Bauer - One of the best experts on this subject based on the ideXlab platform.
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a rapid screening method for the tremorgenic indole Diterpene Alkaloid mycotoxin paxilline in beer
Food Analytical Methods, 2018Co-Authors: Julia I Bauer, Gerd Hamscher, Madeleine Gross, Ewald UsleberAbstract:The tremorgenic paxilline (PAX), an indole-Diterpene Alkaloid mycotoxin, was recently detected as a natural contaminant of ergot of barley and rye. To check the possibility of a transfer of this mycotoxin into beer, a rapid and sensitive immunochemical method for the analysis of PAX in commercial bottled beer was developed. A straightforward sample preparation procedure could be established, including degassing, pH adjustment, optional filtering, and finally a 1:5 dilution with a methanolic phosphate-buffered saline solution. Analysis of PAX was performed by a competitive indirect enzyme immunoassay (EIA). The detection limit at a cut-off value of 80% B/B0 of the EIA standard curve was evaluated by analysis of spiked beer. PAX at levels of 3 μg/L and 5 μg/L yielded 69% and 100% positive results, therefore the detection limit in beer was at 5 μg/L. Recoveries of PAX at levels of 5–20 μg/L were 88–97%, coefficients of variation were 17–22%. With these characteristics, the EIA was considered to be a suitable screening method for PAX in beer. A survey of bottled beer from the German market was conducted which included 38 samples of domestic and international brands, the latter containing various flavoring ingredients. All samples were clearly negative for PAX, which indicates that this toxin is not a relevant contaminant in beer.
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Detection of the tremorgenic mycotoxin paxilline and its desoxy analog in ergot of rye and barley: a new class of mycotoxins added to an old problem
Analytical and Bioanalytical Chemistry, 2017Co-Authors: Julia I Bauer, Gerd Hamscher, Sandra Wegner, Heike Hausmann, Benedikt Cramer, Madeleine Gross, Ewald UsleberAbstract:A newly developed enzyme immunoassay (EIA) for the detection of the tremorgenic indole-Diterpene Alkaloid paxilline (PAX) and closely related analogs was used to analyze ergot sclerotia collected from rye and barley fields. The mean EIA standard curve detection limit was 0.47 ± 0.14 ng/mL; relative cross-reactivity of toxin standard solutions was found for 11-hydroxy-paspaline (terpendole E, 1.1%) but not for lolitrem B or ergot Alkaloids. Sclerotia from all fields were positive in the PAX-EIA at concentration levels of 620 ± 200 and 160 ± 37 μg/kg in ergot of rye and 130 ± 47 μg/kg in ergot of barley. Confirmatory analyses of sclerotia by liquid chromatography-tandem mass spectrometric detection identified PAX and its analog 13-desoxypaxilline. To the best of our knowledge, this is the first report on the natural occurrence of tremorgenic indole-Diterpene Alkaloid mycotoxins in ergot sclerotia from rye and barley. Along with details on the analytical methodology developed in this study, particularly PAX-antibody production, the relevance and implications of these findings for food and feed safety are discussed. Presence or absence of elevated levels of tremorgenic mycotoxins, along with the ergot Alkaloids, would help in explaining the difference between the two distinct manifestations of historic ergotism, the convulsive and the gangrenous form. Further method development for paxilline and other tremorgenic mycotoxins in cereals used for food and feed is a prerequisite for a comprehensive risk assessment, which seems to be necessary in light of the findings reported here. Paxilline in ergot of rye
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detection of the tremorgenic mycotoxin paxilline and its desoxy analog in ergot of rye and barley a new class of mycotoxins added to an old problem
Analytical and Bioanalytical Chemistry, 2017Co-Authors: Julia I Bauer, Gerd Hamscher, Sandra Wegner, Heike Hausmann, Benedikt Cramer, Madeleine Gross, Ewald UsleberAbstract:A newly developed enzyme immunoassay (EIA) for the detection of the tremorgenic indole-Diterpene Alkaloid paxilline (PAX) and closely related analogs was used to analyze ergot sclerotia collected from rye and barley fields. The mean EIA standard curve detection limit was 0.47 ± 0.14 ng/mL; relative cross-reactivity of toxin standard solutions was found for 11-hydroxy-paspaline (terpendole E, 1.1%) but not for lolitrem B or ergot Alkaloids. Sclerotia from all fields were positive in the PAX-EIA at concentration levels of 620 ± 200 and 160 ± 37 μg/kg in ergot of rye and 130 ± 47 μg/kg in ergot of barley. Confirmatory analyses of sclerotia by liquid chromatography-tandem mass spectrometric detection identified PAX and its analog 13-desoxypaxilline. To the best of our knowledge, this is the first report on the natural occurrence of tremorgenic indole-Diterpene Alkaloid mycotoxins in ergot sclerotia from rye and barley. Along with details on the analytical methodology developed in this study, particularly PAX-antibody production, the relevance and implications of these findings for food and feed safety are discussed. Presence or absence of elevated levels of tremorgenic mycotoxins, along with the ergot Alkaloids, would help in explaining the difference between the two distinct manifestations of historic ergotism, the convulsive and the gangrenous form. Further method development for paxilline and other tremorgenic mycotoxins in cereals used for food and feed is a prerequisite for a comprehensive risk assessment, which seems to be necessary in light of the findings reported here.
Xiao Xue Wang - One of the best experts on this subject based on the ideXlab platform.
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An unusual racemic C12-norabietane Diterpene and a new abietane Diterpene Alkaloid from Salvia miltiorrhiza Bunge
Fitoterapia, 2017Co-Authors: Jun He, Bing-zhi Ma, Xiao Xue Wang, Wei-ku Zhang, Jia Zhang, Jie-kun XuAbstract:Abstract A rare C12-norabietane Diterpene racemate (1) and a new abietane Diterpene Alkaloid (2) were isolated from the roots of Salvia miltiorrhiza Bunge. Their structures were established by comprehensive spectroscopic analyses, and 1 was successfully resolved by chiral HPLC, demonstrating that 1 is racemic. The absolute configurations of 1a [(+)-miltiorolide A], 1b [(−)-miltiorolide A], and 2 were determined using TDDFT-ECD calculations. 1a and 1b are the first examples of enantiomeric C12-norabietane Diterpenes featuring an isobutylene with a tetrahydronaphthalene-butyrolactone ring system. The cytotoxic activities of the isolates (1 and 2) were evaluated against three human cancer cell lines BEL-7402, HT-29 and PANC-28. A plausible biogenetic pathway of 1 was also proposed.
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An unusual racemic C12-norabietane Diterpene and a new abietane Diterpene Alkaloid from Salvia miltiorrhiza Bunge
Fitoterapia, 2017Co-Authors: Jun He, Bing-zhi Ma, Xiao Xue Wang, Wei-ku Zhang, Jia Zhang, Jie-kun XuAbstract:Abstract A rare C12-norabietane Diterpene racemate (1) and a new abietane Diterpene Alkaloid (2) were isolated from the roots of Salvia miltiorrhiza Bunge. Their structures were established by comprehensive spectroscopic analyses, and 1 was successfully resolved by chiral HPLC, demonstrating that 1 is racemic. The absolute configurations of 1a [(+)-miltiorolide A], 1b [(−)-miltiorolide A], and 2 were determined using TDDFT-ECD calculations. 1a and 1b are the first examples of enantiomeric C12-norabietane Diterpenes featuring an isobutylene with a tetrahydronaphthalene-butyrolactone ring system. The cytotoxic activities of the isolates (1 and 2) were evaluated against three human cancer cell lines BEL-7402, HT-29 and PANC-28. A plausible biogenetic pathway of 1 was also proposed.