6 results on '"Mori, Naoki"'
Search Results
2. Identification of Plasmalogen in the gut of silkworm (Bombyx mori)
- Author
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Aboshi, Takako, Nishida, Ritsuo, and Mori, Naoki
- Subjects
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SILKWORMS , *PLASMALOGENS , *OXIDATIVE stress , *MOLECULAR weights , *ANTIOXIDANTS , *FATTY acids , *LIQUID chromatography-mass spectrometry , *IONIZATION (Atomic physics) - Abstract
Abstract: Herbivorous insect species are constantly challenged with endogenous and exogenous oxidative stress. Consequently, they possess an array of antioxidant enzymes and small molecular weight antioxidants. Lipid-soluble small molecular antioxidants, such as tocopherols, have not been well studied in insects but may play important antioxidant roles. In this study, we identified plasmalogen phosphatidylethanolamines (pPEs) as well as α-, β/γ-, δ-tocopherol in the larvae of the silkworm Bombyx mori by LCMS analyses and examined their distribution. Plasmalogen are reported to inhibit the metal ion induced oxidation. The composition of tocopherols was the same among gut contents, gut tissues, and the other tissues. However, plasmalogens, a unique class of glycerophospholipids rich in polyunsaturated fatty acids and containing a vinyl ether bond at the sn-1 position, were mainly distributed in gut tissues. Plasmalogens might protect gut tissues from oxidation stress. [Copyright &y& Elsevier]
- Published
- 2012
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3. Biosynthesis of linoleic acid in Tyrophagus mites (Acarina: Acaridae).
- Author
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Aboshi, Takako, Shimizu, Nobuhiro, Nakajima, Yuji, Honda, Yoshiyuki, Kuwahara, Yasumasa, Amano, Hiroshi, and Mori, Naoki
- Subjects
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BIOSYNTHESIS , *LINOLEIC acid , *TYROPHAGUS , *MITES , *ACARIDAE , *PALMITIC acid , *LECITHIN - Abstract
Abstract: We report here that Tyrophagus similis and Tyrophagus putrescentiae (Astigmata: Acaridae) have the ability to biosynthesize linoleic acid [(9Z, 12Z)-9, 12-octadecadienoic acid] via a Δ12-desaturation step, although animals in general and vertebrates in particular appear to lack this ability. When the mites were fed on dried yeast enriched with d 31 -hexadecanoic acid (16:0), d 27 -octadecadienoic acid (18:2), produced from d 31 -hexadecanoic acid through elongation and desaturation reactions, was identified as a major fatty acid component of phosphatidylcholines (PCs) and phosphatidylethanolamines (PEs) in the mites. The double bond position of d 27 -octadecadienoic acid (18:2) of PCs and PEs was determined to be 9 and 12, respectively by dimethyldisulfide (DMDS) derivatization. Furthermore, the GC/MS retention time of methyl 9, 12-octadecadienoate obtained from mite extracts agreed well with those of authentic linoleic acid methyl ester. It is still unclear whether the mites themselves or symbiotic microorganisms are responsible for inserting a double bond into the Δ12 position of octadecanoic acid. However, we present here the unique metabolism of fatty acids in the mites. [Copyright &y& Elsevier]
- Published
- 2013
- Full Text
- View/download PDF
4. Phospholipid biosynthesis in the gut of Spodoptera litura larvae and effects of tannic acid ingestion
- Author
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Aboshi, Takako, Yoshinaga, Naoko, Nishida, Ritsuo, and Mori, Naoki
- Subjects
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PHOSPHOLIPIDS , *BIOSYNTHESIS , *SPODOPTERA littoralis , *INSECT larvae , *TANNINS , *INGESTION , *POLYPHENOLS , *DIGESTIVE enzymes , *INSECT-plant relationships - Abstract
Abstract: Tannins are polyphenols and defensive molecules occurring widely in plants. Dietary tannin may bind digestive enzymes of herbivores and affect them by reducing digestibility. In lepidopteran caterpillars, lysophosphatidylcholine (lysoPC), known as surfactants present in the guts, are thought to interfere with tannin–protein interactions. However, details of biosynthetic pathways of lysoPC in caterpillars have not been paid attention. Here, we investigated biosyntheses of lysoPC in Spodoptera litura larvae. S. litura larvae were fed on artificial diets enriched with [U-13C]linolenic acid for 3h, and then phospholipids in the gut contents were analyzed by LCMS-IT-TOF. Labeled linolenic acid was incorporated into lysoPC as well as diacylPC, diacylphosphatidylethanolamine (diacylPE) and diacylphosphatidylinositol (diacylPI). Detailed investigation on the biosynthesis revealed that [U-13C]linolenic acid was incorporated into phospholipids in gut tissues and then the biosynthesized phospholipids were released to the gut lumen, and then some of diacylPC were hydrolyzed to lysoPC in the gut lumen. When S. litura larvae were fed on artificial diets enriched with tannic acid, a significant increase in the activity to produce diacylPC in the gut tissues was observed. The activated diacylPC production leading to an increase of lysoPC in the larvae might be the adaptively-tuned mechanisms against plant tannins. [Copyright &y& Elsevier]
- Published
- 2010
- Full Text
- View/download PDF
5. Identification of crinosterol from astigamatid mites
- Author
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Murakami, Kenjiro, Watanabe, Bunta, Nishida, Ritsuo, Mori, Naoki, and Kuwahara, Yasumasa
- Subjects
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MITES , *ARTHROPODA , *ACAROLOGY , *ARACHNIDA - Abstract
Abstract: A 24-alkylsterol, crinosterol [(24S)-24-methylcholesta-5,22(E)-dien-3β-ol] has been isolated from sea-dwelling animals, protists and plants. Here, we identified crinosterol from nine species of mites (Acari). The compound was identified by using 1H-NMR analysis and GCMS spectral data along with the HPLC retention time by comparing with those of the synthesized compound. As far as we know, this is the first report on the identification of crinosterol from arthropods. Furthermore, after Rhizoglyphus robini were fed on artificial diets with d 3-methionine, d 2-crinosterol was detected from the mite''s extracts. The incorporation of two deuterium atoms into the sterol indicated that a d 3-methyl group was introduced into the C24 of the side chain to form crinosterol. Although the details of the biosynthesis of crinosterol remain unknown, the discovery of crinosterol in the mites implies the existence of interesting sterol metabolisms in the animals. [Copyright &y& Elsevier]
- Published
- 2007
- Full Text
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6. In vitro biosynthesis of volicitin in Spodoptera litura
- Author
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Yoshinaga, Naoko, Morigaki, Nobuyoshi, Matsuda, Fumio, Nishida, Ritsuo, and Mori, Naoki
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SPODOPTERA littoralis , *AMINO acids , *GLUTAMINE , *TISSUES , *GASTROINTESTINAL system - Abstract
Abstract: Volicitin [N-(17-hydroxylinolenoyl)-l-glutamine] and N-linolenoyl-l-glutamine, originally identified in the regurgitant of Spodoptera exigua, induce damaged corn leaves to release volatile compounds which enable parasitic wasps to locate host caterpillars. Here we demonstrate the in vitro biosynthesis of volicitin for the first time by using gut tissues of Spodoptera litura larvae, as well as N-linolenoyl-l-glutamine. When crop, midgut tissues, peritrophic membrane and gut contents isolated from S. litura were incubated with sodium linolenate and l-[α-15N] glutamine, not only 15N-labeled N-linolenoyl-l-glutamine but 15N-labeled volicitin was detected mainly in the midgut incubation by LCMS and LCMSMS analysis. In contrast, there were negligible amounts of the newly biosynthesized compounds in the gut content incubation. Furthermore, the microsomal fraction obtained from the gut tissues clearly showed specific incorporation of glutamine. This substrate selectivity accounts for the exclusive uptake of glutamine by fatty acid amides (FAAs) in the noctuid caterpillars, even though glutamine was not a major component in the regurgitant. Additionally, intensive chemical analyses revealed that more than 20% of glutamine in hemolymph was present as conjugates in gut contents. These results suggest that FAA compounds are actively synthesized by caterpillar tissues and might play important physiological role(s) in glutamine metabolism. [Copyright &y& Elsevier]
- Published
- 2005
- Full Text
- View/download PDF
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