Kunio Katō

A new facile methylation method for cell-wall polysaccharides

Abstract A new methylation method involving powdered sodium hydroxide and methyl iodide has been developed for the facile methylation of cell-wall polysaccharides. Commercial cellulose powder, wood cellulose, and unbleached kraft pulp in solution in SO 2 -diethylamine-methyl sulfoxide could be completely methylated. Suspensions of holocelluloses, prepared from spruce and beech wood-meals and containing Nicotiana tabacum (CWM), were almost completely methylated in one step. Some decarboxylation occurred with the latter polymers.

A stereoselective synthesis of “natural” (4S,6S,7S)-serricornin, the sex pheromone of cigarette bettle, from levoglucosenone

Abstract The natural stereoisomer of serricornin was synthesized stereoselectively from levoglucosenone. This firmly established the absolute stereochemistry of serricornin to be 4S,6S,7S. A short synthesis of (−)-δ-multistriatin was also reported.

Structural investigation of the arabinoxyloglucan from Nicotiana tabacum

Abstract The structure of tobacco arabinoxyloglucan has been further studied by methylation analysis, by 1 H-, and 13 C-n.m.r., and by fd. mass spectrometry, after complete digestion by cellulase. The results showed the polysaccharide molecule to be composed of two parts; a hexasaccharide component (AraXyl 2 Glc 3 , 1 ) and an unsubstituted (1→4)-β- d -glucan region (4- O -linked glucosyl residues) in the molar ratio of ∼ 1:2. Some heterogeneities of this structure in the arabinofuranosyl sub-group were also found.

Pyrolytic formation of 3-hydroxy-2-penteno-1,5-lactone from xylan, xylo-oligosaccharides, and methyl xylopyranosides

Abstract Xylan, xylotriose, and xylobiose were heated for 3 sec at 386 and 423° in helium as carrier gas. The major, volatile decomposition-products of the foregoing compounds were 3-hydroxy-2-penteno-1,5-lactone and 2-furaldehyde. Lactone formation also occurred on pyrolysis of methyl α- and β-D-xylopyranosides, although the yields of volatile products were very low, except for methanol, which was derived from the aglycon. The relative yield of the lactone decreased as the number of non-reducing xylopyranosyl residues in the molecule decreased. None of the lactone could be found in the pyrolyzate of D-xylose, whereas 2-furaldehyde was formed from all of the samples. These results suggest that 3-hydroxy-2-penteno-1,5-lactone is formed independent from the formation of 2-furaldehyde, and that the lactone arises from the non-reducing xylopyranosyl residues in the molecule. The results of dynamic thermal analyses of xylan, xylo-oligosaccharides, D-xylose, and methyl β-D-xylo-pyranoside are also reported.

A galactoglucomannan from extracellular polysaccharides of suspension-cultured cells of Nicotiana tabacum

Abstract A polysaccharide containing d -xylose, l -arabinose, d -mannose, d -galactose and d -glucose residues in the molar ratio of 0.07:0.16:1.

A galactoglucomannan from cell walls of suspension-cultured tobacco (Nicotiana tabacum) cells

Abstract Cell-wall polysaccharides of suspension-cultured cells of Nicotiana tabacum were fractionated into EDTA-soluble, 5% and 24% potassium hydroxide-soluble, and α-cellulose components. From the 24% potassium hydroxide-soluble fraction, a polysaccharide composed of d -galactose, d -glucose, and d -mannose in approximately equal proportions was purified by ion-exchange chromatography and barium hydroxide precipitation. Methylation analysis, enzymic hydrolysis, and 13 C-n.m.r. studies showed that the polysaccharide was built up of (1→4)-linked, alternating β- d -glucopyranosyl and β- d -mannopyranosyl residues, and that ∼83% of the mannosyl residues were substituted at O-6 by α- d -galactopyranosyl or 2- O -β- d -galactopyranosyl-α- d -galactopyranosyl side-chains.

Structural investigation of a galactoglucomannan from cell walls of tobacco (Nicotiana tabacum) midrib

Abstract Cell-wall polysaccharides of the midrib of Nicotiana tabacum were fractionated into pectin, hemicellulose, and α-cellulose components. From the α-cellulose fraction, a polymer composed of d -galactose, d -glucose, and d -mannose in the molar ratios ∼1:2:4 was extracted by aqueous 25% sodium hydroxide-5% boric acid and purified by barium hydroxide precipitation, ion-exchange chromatography, and gel filtration. Methylation analysis, enzymic degradation, and 13 C-n.m.r. studies showed that the polysaccharide was built up of (1→4)-linked β- d -glucopyranosyl and β- d -mannopyranosyl residues in the molar ratio ∼1:2, and that ∼14% of the d -mannosyl residues were substituted at O-6 by α- d -galactopyranosyl or 2- O -β- d -galactopyranosyl-α- d -galactopyranosyl side-chains.

An arabinoglucuronomannan from suspension-cultured cells of Nicotiana tabacum

Abstract From the soluble polysaccharides of suspension-cultured, tobacco cells ( Nicotiana tabacum ), an arabinoglucuronomannan (AGM) was isolated from the extract with phosphate buffer. Application of partial hydrolysis with acid, carboxyl reduction, methylation analysis, and 1 H- and 13 C-n.m.r. spectroscopy indicated AGM to consist of the tetrasaccharide repeating-unit .

Isolation of (−)-1,2-dehydro-α-cyperone and solavetivone from Lycium chinense

Abstract The investigation of volatile components of Lycium chinense afforded (−)-1,2-dehydro-α-cyperone and solavetivone. (−)-1,2-Dehydro-α-cyperon

Methylation analysis of extracellular polysaccharides from suspension-cultured cells of Nicotiana tabacum

Abstract The soluble extracellular polysaccharides (ECP) of suspension-cultured tobacco cells were fractionated by DEAE-Sephadex CC into seven sub-fractions. Su