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Hiromu Kameoka - One of the best experts on this subject based on the ideXlab platform.

  • Biological stereoselective reduction of 2,6- and 3,5-dimethylcyclohexanones by Glomerella cingulata
    Journal of Chemical Technology & Biotechnology, 1999
    Co-Authors: Mitsuo Miyazawa, Shigeaki Okamura, Hiromu Kameoka
    Abstract:

    The microbial transformations of 2,6- and 3,5-dimethylcyclohexanone were investigated using the plant pathogenic fungus, Glomerella cingulata. With this organism 2,6- and 3,5-dimethylcyclohexanone gave the corresponding 2,6- and 3,5-dimethylcyclohexanol. The metabolites from 2,6-dimethylcyclohexanone indicated enantioselective reduction by specific optical rotation of the products. The enantiomeric excesses of the microbiological reduction products were determined by 1H-NMR spectra of (+)-MTPA-esters of the alcohols produced. The reduction of 2,6-dimethylcyclohexanone was stereospecific, with the (2R,6R)-ketone being converted to the corresponding (2R,6R)-(−)-2,6-dimethylcyclohexanol; absolute configuration, 70% ee. On the other hand, 3,5-dimethylcyclohexanone gave the (1α,3α,5α)-3,5-dimethylcyclohexanol (74%) and (1α,3β,5β)-3,5-dimethylcyclohexanol (26%). © 1999 Society of Chemical Industry

  • biotransformation of the sesquiterpenoid γ gurjunene using a plant pathogenic fungus Glomerella cingulata as a biocatalyst
    Phytochemistry, 1998
    Co-Authors: Yoshihiro Honjo, Hiromu Kameoka
    Abstract:

    Abstract The biotransformation of a sesquitepenod which possesses a guaiane skeleton, (+)- γ -gurjunene has been investigated using the plant pathogenic fungus, Glomerella cingulata as a biocatalyst. (+)- γ -Gurjunene was oxidized at the double bond of the isopropenyl group to (1 S ,4 S ,7 R ,10 R )-5-guaien-11,13-diol and in addition oxidized at the C–10 position to (1 S ,4 S ,7 R ,10 S )-5-guaien-10,11,13-triol. The structures of the metabolic products have been elucidated on the basis of their spectral data.

  • biotransformation of lavandulol by the plant pathogenic fungus Glomerella cingulata
    Journal of Agricultural and Food Chemistry, 1998
    Co-Authors: Hirokazu Nankai, Shinichi Akazawa, Hiromu Kameoka
    Abstract:

    To clarify the structures of biotransformation products and the metabolic pathways, the microbial transformation of (±)-lavandulol has been investigated using the plant pathogenic fungus Glomerella cingulata. (±)-Lavandulol [(±)-5-methyl-2-(1-methylethenyl)-4-hexen-1-ol] was mainly oxidized at the C-4 double bond to give (−)-(2S,4S)-1,5-epoxy-5-methyl-2-(1-methylethenyl)-4-hexanol and cis- and trans-1,4-epoxy-5-methyl-2-(1-methylethenyl)-5-hexanol. 5-Methyl-2-(1-methylethenyl)-4-hexene-1,6-diol (6-hydroxylavandulol) was also produced through this biotransformation. These structures were confirmed by the mass, IR, 1H NMR, and 13C NMR spectral data. Keywords: Biotransformation; microbial transformation; Glomerella cingulata; plant pathogenic fungus; (±)-lavandulol; tetrahydropyran; tetrahydrofuran

  • Biotransformation of (2Z,6Z)-farnesol by the plant pathogenic fungus Glomerella cingulata
    Phytochemistry, 1998
    Co-Authors: Hirokazu Nankai, Hiromu Kameoka
    Abstract:

    Abstract The microbial transformation of (2 Z ,6 Z )-farnesol was investigated using the plant pathogenic fungus, Glomerella cingulata as a biocatalyst. Oxidation of the remote double bond and isomerization of the 2,3-double bond gave (2 Z ,6 Z )-3,7,11-trimethyl-2,6-dodecadiene-1,10,11-triol and (2 E ,6 Z )-3,7,11-trimethyl-2-6-dodecadiene-1,10,11-triol as major metabolites. One of the further degraded compounds, ( Z )-9,10-dihydroxy-6,10-dimethyl-5-undecen-2-one, was also obtained.

  • biotransformation of cis myrtanol and trans myrtanol by plant pathogenic fungus Glomerella cingulata
    Phytochemistry, 1997
    Co-Authors: Yasuhiro Suzuki, Hiromu Kameoka
    Abstract:

    Abstract The biotransformation of the diastereoisomers, (−)-cis-myrtanol and (+)-trans-myrtanol, by Glomerella cingulata has been investigated. (−)-cis-Myrtanol was initially converted to (3S)-3-hydroxy-cis-myrtanol, (4R)-4-hydroxy-cis-myrtanol, 5-hydroxy-cis-myrtanol and [1R, 4R, 5S]-thujane-7, 10-diol having the cyclopropane ring. (4R)-4-Hydroxy-cis-myrtanol was further converted to 4-oxo-cis-myrtanol. By comparison (+)-trans-myrtanol was converted to 3-oxo-trans-myrtanol, 9-hydroxy-trans-myrtanol, 4-oxo-trans-myrtanic acid and 5-hydroxy-trans-myrtanic acid. The structures of the metabolic products were determined by spectral methods. © 1997 Elsevier Science Ltd. All rights reserved

Hirokazu Nankai - One of the best experts on this subject based on the ideXlab platform.

Deokkun Oh - One of the best experts on this subject based on the ideXlab platform.

  • production of 7 8 dihydroxy unsaturated fatty acids from plant oils by whole recombinant cells expressing 7 8 linoleate diol synthase from Glomerella cingulata
    Journal of Agricultural and Food Chemistry, 2016
    Co-Authors: Woo-ri Kang, Kyung-chul Shin, Deokkun Oh
    Abstract:

    The reaction conditions for the production of 7S,8S-dihydroxy-9,12(Z,Z)-octadecadienoic acid from linoleic acid by recombinant Escherichia coli expressing 7,8-linoleate diol synthase from Glomerella cingulata were optimized using response surface methodology. The optimal reaction conditions were pH 7.0, 18.6 °C, 10.8% (v/v) dimethyl sulfoxide, 44.9 g/L cells, and 14.3 g/L linoleic acid, with agitation at 256 rpm. Under these conditions, recombinant cells produced 7,8-dihydroxy unsaturated fatty acids in the range of 7.0–9.8 g/L from 14.3 g/L linoleic acid, 14.3 g/L oleic acid, and plant oil hydrolysates such as waste oil and olive oil containing 14.3 g/L linoleic acid or oleic acid. To the best of the authors’ knowledge, this is the first report on the biotechnological production of 7,8-dihydroxy unsaturated fatty acids.

Zhenfang Zhang - One of the best experts on this subject based on the ideXlab platform.

  • effects of temperature wetness duration and moisture on the conidial germination infection and disease incubation period of Glomerella cingulata
    Plant Disease, 2015
    Co-Authors: Bing Wang, Caixia Wang, Xiangli Dong, Baohua Li, Zhenfang Zhang
    Abstract:

    Abstract Glomerella leaf spot (GLS) caused by Glomerella cingulata is a newly emergent disease that results in severe defoliation and fruit spots. Currently, GLS is not effectively controlled in China due to a lack of understanding of its epidemiology. Therefore, the effects of temperature, wetness duration, and moisture on conidial germination, infection, and the disease incubation period of GLS were examined by inoculating cv. Gala apple leaves with a conidial suspension and performing in vitro germination assays. Conidia could germinate and form appressoria at temperatures ranging from 5 to 35°C, with an optimum temperature of 27.6°C. The germination of conidia required free water or a nearly saturated relative humidity, with only a few conidia germinating and forming appressoria when the RH was less than 99%. The conidial germination dynamics at 10, 25, and 30°C were well represented by three logistic models. The infection of cv. Gala apple leaves by conidia occurred at temperatures ranging from 15 to...

  • effects of temperature wetness duration and moisture on the conidial germination infection and disease incubation period of Glomerella cingulata
    Plant Disease, 2015
    Co-Authors: Bing Wang, Caixia Wang, Xiangli Dong, Zhenfang Zhang
    Abstract:

    Glomerella leaf spot (GLS) caused by Glomerella cingulata is a newly emergent disease that results in severe defoliation and fruit spots. Currently, GLS is not effectively controlled in China due to a lack of understanding of its epidemiology. Therefore, the effects of temperature, wetness duration, and moisture on conidial germination, infection, and the disease incubation period of GLS were examined by inoculating cv. Gala apple leaves with a conidial suspension and performing in vitro germination assays. Conidia could germinate and form appressoria at temperatures ranging from 5 to 35°C, with an optimum temperature of 27.6°C. The germination of conidia required free water or a nearly saturated relative humidity, with only a few conidia germinating and forming appressoria when the RH was less than 99%. The conidial germination dynamics at 10, 25, and 30°C were well represented by three logistic models. The infection of cv. Gala apple leaves by conidia occurred at temperatures ranging from 15 to 35°C. The minimum wetness duration required for infection by conidia at different temperatures was described using a polynomial equation, and the lowest minimum wetness duration was 2.76 h, which occurred at 27.6°C according to the polynomial. Successful infection by conidia was represented by the number of lesions per leaf, which increased with extended wetness durations at the conidial infection stage for six tested temperatures, with the exception of 10°C, when the minimum wetness durations were satisfied. The associations of successfully infected conidia with wetness duration at temperatures of 15, 20, 25, and 30°C were described by four logistic models. Conidia infections developed into visible lesions at temperatures ranging from 15 to 30°C, and the shortest incubation period of 2 days was observed at 25°C. These data and models can be used to construct forecasting models and develop effective control systems for Glomerella leaf spot.

Woo-ri Kang - One of the best experts on this subject based on the ideXlab platform.

  • production of 7 8 dihydroxy unsaturated fatty acids from plant oils by whole recombinant cells expressing 7 8 linoleate diol synthase from Glomerella cingulata
    Journal of Agricultural and Food Chemistry, 2016
    Co-Authors: Woo-ri Kang, Kyung-chul Shin, Deokkun Oh
    Abstract:

    The reaction conditions for the production of 7S,8S-dihydroxy-9,12(Z,Z)-octadecadienoic acid from linoleic acid by recombinant Escherichia coli expressing 7,8-linoleate diol synthase from Glomerella cingulata were optimized using response surface methodology. The optimal reaction conditions were pH 7.0, 18.6 °C, 10.8% (v/v) dimethyl sulfoxide, 44.9 g/L cells, and 14.3 g/L linoleic acid, with agitation at 256 rpm. Under these conditions, recombinant cells produced 7,8-dihydroxy unsaturated fatty acids in the range of 7.0–9.8 g/L from 14.3 g/L linoleic acid, 14.3 g/L oleic acid, and plant oil hydrolysates such as waste oil and olive oil containing 14.3 g/L linoleic acid or oleic acid. To the best of the authors’ knowledge, this is the first report on the biotechnological production of 7,8-dihydroxy unsaturated fatty acids.

  • Production of 7,8-Dihydroxy Unsaturated Fatty Acids from Plant Oils by Whole Recombinant Cells Expressing 7,8-Linoleate Diol Synthase from Glomerella cingulata
    2016
    Co-Authors: Min-ju Seo, Woo-ri Kang, Kyung-chul Shin
    Abstract:

    The reaction conditions for the production of 7S,8S-dihydroxy-9,12­(Z,Z)-octadecadienoic acid from linoleic acid by recombinant Escherichia coli expressing 7,8-linoleate diol synthase from Glomerella cingulata were optimized using response surface methodology. The optimal reaction conditions were pH 7.0, 18.6 °C, 10.8% (v/v) dimethyl sulfoxide, 44.9 g/L cells, and 14.3 g/L linoleic acid, with agitation at 256 rpm. Under these conditions, recombinant cells produced 7,8-dihydroxy unsaturated fatty acids in the range of 7.0–9.8 g/L from 14.3 g/L linoleic acid, 14.3 g/L oleic acid, and plant oil hydrolysates such as waste oil and olive oil containing 14.3 g/L linoleic acid or oleic acid. To the best of the authors’ knowledge, this is the first report on the biotechnological production of 7,8-dihydroxy unsaturated fatty acids