The Experts below are selected from a list of 615 Experts worldwide ranked by ideXlab platform
Hiroshi Noguchi - One of the best experts on this subject based on the ideXlab platform.
-
engineered biosynthesis of plant polyketides chain length control in an octaketide producing plant type iii polyketide synthase
Journal of the American Chemical Society, 2005Co-Authors: Satoshi Oguro, Yoriko Utsumi, Yukie Sano, Hiroshi NoguchiAbstract:The chalcone synthase (CHS) superfamily of type III polyketide synthases (PKSs) produces a variety of plant secondary metabolites with remarkable structural diversity and biological activities (e.g., chalcones, stilbenes, benzophenones, acrydones, phloroglucinols, resorcinols, pyrones, and chromones). Here we describe an octaketide-producing novel plant-specific type III PKS from Aloe (Aloe Arborescens) sharing 50-60% amino acid sequence identity with other plant CHS-superfamily enzymes. A recombinant enzyme expressed in Escherichia coli catalyzed seven successive decarboxylative condensations of malonyl-CoA to yield aromatic octaketides SEK4 and SEK4b, the longest polyketides known to be synthesized by the structurally simple type III PKS. Surprisingly, site-directed mutagenesis revealed that a single residue Gly207 (corresponding to the CHS's active site Thr197) determines the polyketide chain length and product specificity. Small-to-large substitutions (G207A, G207T, G207M, G207L, G207F, and G207W) resulted in loss of the octaketide-forming activity and concomitant formation of shorter chain length polyketides (from triketide to heptaketide) including a pentaketide chromone, 2,7-dihydroxy-5-methylchromone, and a hexaketide pyrone, 6-(2,4-dihydroxy-6-methylphenyl)-4-hydroxy-2-pyrone, depending on the size of the side chain. Notably, the functional diversity of the type III PKS was shown to evolve from simple steric modulation of the chemically inert single residue lining the active-site cavity accompanied by conservation of the Cys-His-Asn catalytic triad. This provided novel strategies for the engineered biosynthesis of pharmaceutically important plant polyketides.
-
a plant type iii polyketide synthase that produces pentaketide chromone
Journal of the American Chemical Society, 2005Co-Authors: Ikuro Abe, Satoshi Oguro, Yoriko Utsumi, Yukie Sano, Hiroyuki Morita, Hiroshi NoguchiAbstract:A novel plant-specific type III polyketide synthase (PKS) that catalyzes formation of a pentaketide chromone, 5,7-dihydroxy-2-methylchromone, from five molecules of malonyl-CoA, was cloned and sequenced from Aloe (Aloe Arborescens). Site-directed mutagenesis revealed that Met207 (corresponding to Thr197 in CHS) determines the polyketide chain length and the product specificity of the enzyme; remarkably, replacement of a single amino acid residue, Met207, with Gly yielded a mutant enzyme that efficiently produces aromatic octaketides, SEK4 and SEK4b, the products of the minimal PKS for actinorhodin (act from Streptomyces coelicolor), from eight molecules of malonyl-CoA. This provided new insights into the catalytic functions and specificities of the CHS-superfamily type III PKS enzymes.
Hidehiko Beppu - One of the best experts on this subject based on the ideXlab platform.
-
determination of Aloenin barbaloin and isobarbaloin in Aloe species by micellar electrokinetic chromatography
Journal of Chromatography B: Biomedical Sciences and Applications, 2001Co-Authors: Hiroshi Kuzuya, Ikuko Tamai, Hidehiko Beppu, Kan Shimpo, Takeshi ChiharaAbstract:Aloenin, barbaloin and isobarbaloin in JP Aloe1, Aloe barbadensis (Aloe vera) and Aloe Arborescens Miller var. natalensis Berger (Aloe Arborescens Miller) were determined by micellar electrokinetic chromatography (MEKC) with 50 mM sodium dodecyl sulfate. Aloenin, barbaloin and isobarbaloin were well separated by MEKC and as little as 5.5 pg/11 nl of the three compounds could be detected. The determination took around 14 min.
-
in vivo effects of Aloe Arborescens miller var natalensis berger kidachi Aloe on experimental tinea pedis in guinea pig feet
Phytotherapy Research, 1998Co-Authors: Kaoru Kawai, Hidehiko Beppu, Kan Shimpo, Takeshi Chihara, Naoki Yamamoto, Toshiharu Nagatsu, H Ueda, Y YamadaAbstract:Trichophytosis was induced in guinea-pigs and the antifungal effects of Aloe Arborescens Miller var. natalensis Berger (Kidachi Aloe) evaluated in comparison with lanoconazole, a commercially available antifungal agent. Trichophytosis was induced by inoculation of arthrospores of Trichophyton mentagrophytes cephalic strain SM-110 (T. mentagrophytes SM-110) onto the plantar part of guinea-pig feet. Culture studies after application of 30% freeze-dried Kidachi Aloe for 10 days showed a 70% growth inhibition compared with the untreated animals. In an in vitro experiment, the fraction of Kidachi Aloe with molecular weights less than 10 000 and a bioactive compound of barbaloin, a low molecular weight component of Kidachi Aloe, showed growth inhibition of Trichophyton at a minimum concentration of 75 mg/mL and 200 μg/mL. © 1998 John Wiley & Sons, Ltd.
-
inhibitory effect of Aloe Arborescens miller var natalensis berger kidachi Aloe on induction of preneoplastic focal lesions in the rat liver
Phytotherapy Research, 1993Co-Authors: Hiroyuki Tsuda, Hidehiko Beppu, Kazuyuki Matsumoto, Mitsuya Ito, Iwao Hirono, Kaoru Kawai, K Fujita, M NagaoAbstract:Inhibitory effects of freeze-dried Aloe Arborescens Miller var. natalensis Berger (Kidachi Aloe) whole leaf powder (Aloe) on induction of preneoplastic glutathione S-transferase (GST-P) positive hepatocyte foci GST-P + were studied in male rats. Experiment 1: Group 1 was fed a diet containing 30% Aloe for 8 days. At day 7, the carcinogen, 2-amino-3-methylimidazo(4,5-f)quinoline(IQ, 100 mg/kg, i.g., one dose), was given 12 h after partial hepatectomy (PH) for initiation, followed by phenobarbital (PB) and D-galactosamine for promotion and then killed at week 11. Experiment 2: Group 1 was given diethylnitrosamine (DEN, 200 mg/kg, i.p.) for initiation then a diet containing 30, 20 or 10% Aloe during weeks 3-8, with PH at week 3. In both experiments, groups 2 and 3 were treated as in group 1 without Aloe or carcinogens
Kaoru Kawai - One of the best experts on this subject based on the ideXlab platform.
-
in vivo effects of Aloe Arborescens miller var natalensis berger kidachi Aloe on experimental tinea pedis in guinea pig feet
Phytotherapy Research, 1998Co-Authors: Kaoru Kawai, Hidehiko Beppu, Kan Shimpo, Takeshi Chihara, Naoki Yamamoto, Toshiharu Nagatsu, H Ueda, Y YamadaAbstract:Trichophytosis was induced in guinea-pigs and the antifungal effects of Aloe Arborescens Miller var. natalensis Berger (Kidachi Aloe) evaluated in comparison with lanoconazole, a commercially available antifungal agent. Trichophytosis was induced by inoculation of arthrospores of Trichophyton mentagrophytes cephalic strain SM-110 (T. mentagrophytes SM-110) onto the plantar part of guinea-pig feet. Culture studies after application of 30% freeze-dried Kidachi Aloe for 10 days showed a 70% growth inhibition compared with the untreated animals. In an in vitro experiment, the fraction of Kidachi Aloe with molecular weights less than 10 000 and a bioactive compound of barbaloin, a low molecular weight component of Kidachi Aloe, showed growth inhibition of Trichophyton at a minimum concentration of 75 mg/mL and 200 μg/mL. © 1998 John Wiley & Sons, Ltd.
-
inhibitory effect of Aloe Arborescens miller var natalensis berger kidachi Aloe on induction of preneoplastic focal lesions in the rat liver
Phytotherapy Research, 1993Co-Authors: Hiroyuki Tsuda, Hidehiko Beppu, Kazuyuki Matsumoto, Mitsuya Ito, Iwao Hirono, Kaoru Kawai, K Fujita, M NagaoAbstract:Inhibitory effects of freeze-dried Aloe Arborescens Miller var. natalensis Berger (Kidachi Aloe) whole leaf powder (Aloe) on induction of preneoplastic glutathione S-transferase (GST-P) positive hepatocyte foci GST-P + were studied in male rats. Experiment 1: Group 1 was fed a diet containing 30% Aloe for 8 days. At day 7, the carcinogen, 2-amino-3-methylimidazo(4,5-f)quinoline(IQ, 100 mg/kg, i.g., one dose), was given 12 h after partial hepatectomy (PH) for initiation, followed by phenobarbital (PB) and D-galactosamine for promotion and then killed at week 11. Experiment 2: Group 1 was given diethylnitrosamine (DEN, 200 mg/kg, i.p.) for initiation then a diet containing 30, 20 or 10% Aloe during weeks 3-8, with PH at week 3. In both experiments, groups 2 and 3 were treated as in group 1 without Aloe or carcinogens
Vysniauskas Gintautas - One of the best experts on this subject based on the ideXlab platform.
-
Evaluation of herb extracts and germanium oxide as immunological adjuvants in quails ( Coturnix coturnix japonica )
2018Co-Authors: Vysniauskas Gintautas, Bižanov Gazim, Normantienė Teresa, Jonauskienė IrenaAbstract:Objective. The aim of present investigation was to assess the immunostimulatory activity of herb extracts from Allium sativum, Aloe Arborescens and germanium oxide. Materials and methods. Quails were immunized three times orally with bovine serum albumin (BSA) in combination with the crude plant extracts and the inorganic substance which was indicated above. BSA-specific IgA antibodies in saliva and IgY antibodies in egg yolk were tested by ELISA. Results. It was discovered that the birds treated with BSA in combination with either Allium sativum or Aloe Arborescens extracts or germanium oxide had higher titers of BSA-specific IgA antibodies in the saliva at the 42 day of monitoring, while the quails administered with BSA and Allium sativum or Aloe Arborescens extracts or germanium oxide demonstrated higher levels of BSA-specific IgY antibodies in the egg yolk at the end of observation. Furthermore, the birds immunised with BSA alone had significantly lower immune responses to BSA than quails immunised with BSA supplemented with the herb extracts and germanium oxide. Conclusions. These data suggest that medicinal plant extracts and germanium oxide can be applied as oral adjuvants or as immunomodulators for quails.Objetivo. Evaluar la actividad inmunoestimulante de extractos de hierbas de Allium sativum, Aloe Arborescens y óxido de germanio. Materiales y métodos. Las codornices se inmunizaron tres veces por vía oral con albúmina de suero bovino (BSA) en combinación con los extractos vegetales crudos y la sustancia inorgánica antes indicada. Los anticuerpos IgA específicos de la BSA en la saliva y los anticuerpos IgY en la yema de huevo se analizaron mediante ELISA. Resultados. Se encontró que las aves tratadas con BSA en combinación con extractos de Allium sativum o Aloe Arborescens o con óxido de germanio tenían títulos más altos de anticuerpos IgA específicos de BSA en la saliva a los 42 días de seguimiento, mientras que las codornices administradas con BSA y Allium sativum o extractos de Aloe Arborescens u óxido de germanio demostraron niveles más altos de anticuerpos IgY específicos de BSA en la yema de huevo al final de la observación. Además, las aves inmunizadas sólo con BSA tuvieron respuestas inmunitarias significativamente más bajas a la BSA que las codornices inmunizadas con BSA complementadas con extractos de hierbas y óxido de germanio. Conclusiones. Estos datos sugieren que los extractos de plantas medicinales y el óxido de germanio pueden aplicarse como adyuvantes orales o como inmunomoduladores para las codornices
-
Evaluación de extractos de hierbas y el óxido de germanio como adyuvantes inmunológicos en codornices (Coturnix coturnix japonica)
'Universidad de Cordoba', 2018Co-Authors: Bižanov Gazim, Normantienė Teresa, Jonauskienė Irena, Vysniauskas GintautasAbstract:Objective. The aim of present investigation was to assess the immunostimulatory activity of herb extracts from Allium sativum, Aloe Arborescens and germanium oxide. Materials and methods. Quails were immunized three times orally with bovine serum albumin (BSA) in combination with the crude plant extracts and the inorganic substance which was indicated above. BSA-specific IgA antibodies in saliva and IgY antibodies in egg yolk were tested by ELISA. Results. It was discovered that the birds treated with BSA in combination with either Allium sativum or Aloe Arborescens extracts or germanium oxide had higher titers of BSA-specific IgA antibodies in the saliva at the 42 day of monitoring, while the quails administered with BSA and Allium sativum or Aloe Arborescens extracts or germanium oxide demonstrated higher levels of BSA-specific IgY antibodies in the egg yolk at the end of observation. Furthermore, the birds immunised with BSA alone had significantly lower immune responses to BSA than quails immunised with BSA supplemented with the herb extracts and germanium oxide. Conclusions. These data suggest that medicinal plant extracts and germanium oxide can be applied as oral adjuvants or as immunomodulators for quails.Objetivo. El objetivo de la presente investigación fue evaluar la actividad inmunoestimulante de extractos de hierbas de Allium sativum, Aloe Arborescens y óxido de germanio. Materiales y métodos. Las codornices se inmunizaron tres veces por vía oral con albúmina de suero bovino (BSA) en combinación con los extractos vegetales crudos y la sustancia inorgánica antes indicada. Los anticuerpos IgA específicos de la BSA en la saliva y los anticuerpos IgY en la yema de huevo se analizaron mediante ELISA. Resultados. Se encontró que las aves tratadas con BSA en combinación con extractos de Allium sativum o Aloe Arborescens o con óxido de germanio tenían títulos más altos de anticuerpos IgA específicos de BSA en la saliva a los 42 días de seguimiento, mientras que las codornices administradas con BSA y Allium sativum o extractos de Aloe Arborescens u óxido de germanio demostraron niveles más altos de anticuerpos IgY específicos de BSA en la yema de huevo al final de la observación. Además, las aves inmunizadas sólo con BSA tuvieron respuestas inmunitarias significativamente más bajas a la BSA que las codornices inmunizadas con BSA complementadas con extractos de hierbas y óxido de germanio. Conclusiones. Estos datos sugieren que los extractos de plantas medicinales y el óxido de germanio pueden aplicarse como adyuvantes orales o como inmunomoduladores para las codornices
Y Yamada - One of the best experts on this subject based on the ideXlab platform.
-
in vivo effects of Aloe Arborescens miller var natalensis berger kidachi Aloe on experimental tinea pedis in guinea pig feet
Phytotherapy Research, 1998Co-Authors: Kaoru Kawai, Hidehiko Beppu, Kan Shimpo, Takeshi Chihara, Naoki Yamamoto, Toshiharu Nagatsu, H Ueda, Y YamadaAbstract:Trichophytosis was induced in guinea-pigs and the antifungal effects of Aloe Arborescens Miller var. natalensis Berger (Kidachi Aloe) evaluated in comparison with lanoconazole, a commercially available antifungal agent. Trichophytosis was induced by inoculation of arthrospores of Trichophyton mentagrophytes cephalic strain SM-110 (T. mentagrophytes SM-110) onto the plantar part of guinea-pig feet. Culture studies after application of 30% freeze-dried Kidachi Aloe for 10 days showed a 70% growth inhibition compared with the untreated animals. In an in vitro experiment, the fraction of Kidachi Aloe with molecular weights less than 10 000 and a bioactive compound of barbaloin, a low molecular weight component of Kidachi Aloe, showed growth inhibition of Trichophyton at a minimum concentration of 75 mg/mL and 200 μg/mL. © 1998 John Wiley & Sons, Ltd.