Hiroto Kikuchi

A Phenolic amide from roots of Chenopodium album

Abstract A new phenolic amide has been isolated from the roots of Chenopodium album . Its structure was determined as N-trans -feruloyl-4- O -methyldopamine by spectroscopic evidence and chemical synthesis. It showed attracting activity toward the zoospores of Aphanomyces cochlioides , a pathogenic fungus against some plants of Chenopodiaceae.

Industrial production of difructose anhydride III (DFA III) from crude inulin extracted from chicory roots using Arthrobacter sp. H65-7 fructosyltransferase

A practical, economical, and industrial process for the enzymatic production of difructose anhydride III (DFA III) was investigated for crude inulin prepared from chicory roots using Arthrobacter sp. H65-7 fructosyltransferase. A comparable level of DFA III production to that from commercial inulin was obtained using crude inulin, suggesting the feasibility of this production process.

Structural confirmation of oligosaccharides newly isolated from sugar beet molasses

BackgroundSugar beet molasses is a viscous by-product of the processing of sugar beets into sugar. The molasses is known to contain sucrose and raffinose, a typical trisaccharide, with a well-established structure. Although sugar beet molasses contains various other oligosaccharides as well, the structures of those oligosaccharides have not been examined in detail. The purpose of this study was isolation and structural confirmation of these other oligosaccharides found in sugar beet molasses.ResultsFour oligosaccharides were newly isolated from sugar beet molasses using high-performance liquid chromatography (HPLC) and carbon-Celite column chromatography. Structural confirmation of the saccharides was provided by methylation analysis, matrix-assisted laser desorption/ionaization time of flight mass spectrometry (MALDI-TOF-MS), and nuclear magnetic resonance (NMR) measurements.ConclusionThe following oligosaccharides were identified in sugar beet molasses: β-D-galactopyranosyl-(1- > 6)-β-D-fructofuranosyl-(2 <-> 1)-α-D-glucopyranoside (named β-planteose), α-D-galactopyranosyl-(1- > 1)-β-D-fructofuranosyl-(2 <-> 1)-α-D-glucopyranoside (named1-planteose), α-D-glucopyranosyl-(1- > 6)-α-D-glucopyranosyl-(1 <-> 2)-β-D-fructofuranoside (theanderose), and β-D-glucopyranosyl-(1- > 3)-α-D-glucopyranosyl-(1 <-> 2)-β-D-fructofuranoside (laminaribiofructose). 1-planteose and laminaribiofructose were isolated from natural sources for the first time.

One-pot conversion of levan prepared from Serratia levanicum NN to difructose anhydride IV by Arthrobacter nicotinovorans levan fructotransferase

The newly established difructose anhydride IV (DFA IV) production system is comprised of the effective production of levan from sucrose by Serratia levanicum NN, the conversion of the levan into DFA IV by levan fructotransferase from Arthrobacter nicotinovorans GS-9, which is highly expressed in an Escherichiacoli transformant, and a practical purification step. The chemical properties of DFA IV were also investigated.

Influence of Dietary Methionine Level on the Liver Metallothionein mRNA Level in Rats

The effects of some methyl-containing compounds added to a choline-deficient diet on the metallothionein mRNA level in the rat liver were studied. The addition of choline or carnitine to the choline-deficient diet did not induce a gain in body weight, while the addition of either betaine or methionine to the choline-deficient diet, or of methionine to the choline-deficient diet with choline significantly increased the body weight. The metallothionein mRNA level in the liver of rats fed on the choline-deficient diet was similar to that of rats fed on the choline-deficient diet with choline, betaine or carnitine. However, the addition of methionine to the choline-deficient diet with or without choline caused a marked suppression in the metallothionein mRNA level in the liver. It is thus surmised that the metallothionein mRNA level in the liver might be regulated by the dietary content of methionine.

Structural analysis of novel kestose isomers isolated from sugar beet molasses

Eight kestose isomers were isolated from sugar beet molasses by carbon-Celite column chromatography and HPLC. GC-FID and GC-MS analyses of methyl derivatives, MALD-TOF-MS measurements and NMR spectra were used to confirm the structural characteristics of the isomers. The (1)H and (13)C NMR signals of each isomer saccharide were assigned using COSY, E-HSQC, HSQC-TOCSY, HMBC and H2BC techniques. These kestose isomers were identified as α-D-fructofuranosyl-(2- > 2)-α-D-glucopyranosyl-(1 < ->2)-β-D-fructofuranoside, α-D-fructofuranosyl-(2- > 3)-β-D-fructofuranosyl-(2 < ->1)-α-D-glucopyranoside, α-D-fructofuranosyl-(2- > 4)-β-D-fructofuranosyl-(2 < ->1)-α-D-glucopyranoside, β-D-fructofuranosyl-(2- > 4)-β-D-fructofuranosyl-(2 < ->1)-α-D-glucopyranoside, β-D-fructofuranosyl-(2- > 3)-α-D-glucopyranosyl-(1 < ->2)-β-D-fructofuranoside, α-D-fructofuranosyl-(2- > 1)-β-D-fructofuranosyl-(2 < ->1)-α-D-glucopyranoside, α-D-fructofuranosyl-(2- > 6)-α-D-glucopyranosyl-(1 < ->2)-β-D-fructofuranoside, and α-D-fructofuranosyl-(2- > 6)-β-D-fructofuranosyl-(2 < ->1)-α-D-glucopyranoside. The former five compounds are novel saccharides.

Structural confirmation of novel oligosaccharides isolated from sugar beet molasses.

Eleven oligosaccharides were isolated from sugar beet molasses using carbon-Celite column chromatography and HPLC. The constituent sugars and linkage positions were determined using methylation analysis, MALDI-TOF-MS, and NMR measurements. The configurations of isolated oligosaccharides were confirmed based on detailed NMR analysis. Based on our results, three of the 11 oligosaccharides were novel.