Fumiko Yaku

Synthesis of LCC Model Compounds and Their Chemical and Enzymatic Stabilities

Hydrolysis with dioxane-water (1:1) at 180 °C for one hour allows to break the phenylglycosidic linkage but remains undegraded at least 85% of the glycosidic bond at 7-hydroxyl of lignin side chain. Boron tribromide treatment of all model compounds results in a nearly quantitative Splitting of sugar components. The glycosidic bond between carbohydrate and lignin component is hydrolyzed completely by heating with 1N-H2SO4 at 100 °C for 6 hours, but sugar-lignin bond of ether type locating at 7-position of lignin side chain does not undergo acid hydrolysis. Sodium hydroxide (5%) treatment at ambient temperature never cleavage all of the glycosidic bonds synthesized here except compound III, but benzyl ether type locating at -position of phenylpropane unit is unstable even for very dilute alkali. It was found that methyl ether of this type compound, Villa also suffered alkaline degradation even at near ambient.temperature if the prolonged reaction time was employed. Cellulase preparations (Cellulosin AC and AP) hydrolyze quantitatively all of the glycosidic linkages of lignin-carbohydrate synthesized here even though the aglycon is so bulky äs dimer of phenylpropane unit. Enzymatic hydrolysis rate is larger in alkylated phenolic hydroxyl in comparison to free phenolic hydroxyl, in the former, benzylated one being more faster than the ethylated. Phenylxyloside is subjected to enzymatic hydrolysis more easily compared with phenylgiucoside.

Production of N-Acetylglucosamine Deacetylase by Vibrio cholerae Non-O1

Vibrio cholerae non-O1 (1148 A) produced β-N-acetylglucosamini-dase and N-acetylglucosamine (GlcNAc) deacetylase intracellularly when grown in chitin or GlcNAc containing medium. It also secreted chitinase only in the chitin-containing medium. The partially purified GlcNAc deacetylase deacetylated GlcNAc but not chitin oligosaccharides, the dimer to hexamer of GlcNAc. We also detected the reaction product by capillary electrophoresis.

Immobilization of β-Glucosidase using Wood Residue for Enzymatic Hydrolysis

ABSTRACT A significant amount of β-glucosidase and other cellulase components were adsorbed on the residue remaining after enzymatic hydrolysis of cellulosic materials. The wet wood-residue separated from an enzymatic degradation mixture hydrolyzed cellobiose to glucose in a yield of about 100% and retained the activity even after the 30th treatment. These residues were able to be used as an immobilized β-glucosidase preparation. By drying the wet wood residue, only β-glucosidase was retained on it, and the stability of immobilized β-glucosidase increased, although the specific activity decreased significantly.

Polymerization of Acetaldehyde by the Use ob Phosphoric Esters

各種のリン酸エステル,亜リン酸エステル,縮合リン酸ニステルを触媒として,アセトアルデヒドの低温重合をおこない,分子量数千～10万の非晶性ポリエーテル型ポリマーを得た。これらのリン酸エステルがアセトアルデヒドの重合に対し触媒として活性を示すためには, 分子内にP-OHの存在が必要であり, ポリリン酸系触媒の場合に必要であったP-O-P の連鎖を必ずしも必要としないことが認められた。つぎに触媒として使用した各種リン酸化合物の酸強度を測定し重合活性との関係につき検討した結果,カウンターイオンの影響よりも触媒自身の酸強度の影響の方が大きいことが認められた。酸強度の異なるリン酸化合物を触媒として用いると,パラアルデヒドやメタアルデヒドの生成する下限温度には差があり,酸の強い程その温度の低いことを認めた。