著者

坊木 佳人 山田 雅英 北小路 学

出版者

日本応用糖質科学会

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.53, no.4, pp.241-247, 2006

被引用文献数

1

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生薬の抽出残渣に含まれている澱粉の有用性を評価するため,澱粉の物理化学的な諸特性を調べた.生薬は収穫時期あるいは栽培地の異なるものを用いた.澱粉(S)は,<i>Pinellia ternata</i> (Thunb.) Breitenbachの塊茎,ハンゲ(PT),<i>Alisma orientale</i> Juzepczukの塊茎,タクシャ(AO),<i>Coix lacryma-jobi</i> Linn&eacute; var. <i>ma-yuen</i> Stapfの種子,ヨクイニン(CL)から調製した.PT,AO,CLの粉末生薬には,澱粉が41.1-77.5,12.5-40.5,1.5-5.8%含まれていた(Table 1).S-PT,S-AO,S-CLの平均粒子径は8.2&plusmn;0.2-16.0&plusmn;0.4,6.1&plusmn;0.2,11.5&plusmn;0.4-13.5&plusmn;0.4 &mu;mであった(Fig. 1).S-PT,S-AO,S-CLの結晶型はC<small>A</small>型であった(Fig. 3).S-PT,S-AO,S-CLそれぞれの燐含量は62-330,93-110,75-210 &mu;g/g,カルシウム含量は320-530,48-260,18-33 &mu;g/gであった(Table 2).S-PT-1,S-AO-2,S-CL-2の吸熱曲線は67.3-85.0,58.9-84.2,59.2-81.0&deg;Cの範囲内に観察され,エンタルピーはそれぞれ3.4&plusmn;0.3,4.2&plusmn;0.0,4.5&plusmn;0.2 J/gであった(Table 3).これらの澱粉は低エネルギー糊化デンプンとしての利用が期待できる.生澱粉S-PT,S-AO,S-CLの&alpha;-アミラーゼによる72時間後の分解率は35.3&plusmn;2.4,38.3&plusmn;2.3,62.2&plusmn;5.2%であった(Fig. 4).&alpha;-アミラーゼにより生澱粉から生成した(分解率 : S-PT-1,2.4% ; S-AO-2,5.8% ; S-CL-2,7.1%)主な糖類は,三単糖(35.8-40.0%)とマルトース(35.8-42.8%)であった(Table 4).グルコアミラーゼにより生澱粉から生成した(分解率 : S-PT-1,4.8% ; S-AO-2,12.1% ; S-CL-2,18.7%)主な糖は,グルコース(97.6-99.5%)であった(Table 5).S-PT-1,S-AO-2,S-CL-2は,1時間分解後,&alpha;-アミラーゼによって粒子の表面全体が凸凹に侵食されたが,グルコアミラーゼによっては原型をとどめており粒子表面に小粒が付着していた.S-CL-2の粒子には,グルコアミラーゼによってその原型を失っているものもみられた(Fig. 2).&alpha;-アミラーゼにより分解されたS-PT-1(A),S-AO-2(A),S-CL-2(A)は,多孔性のゆえに吸着剤としての利用が期待できる(Fig. 2).糊化温度とエントロピーの結果から,&alpha;-アミラーゼによって分解されたS-PT-1,S-AO-2,S-CL-2の方が,グルコアミラーゼによるものよりも,熱安定性の高いことが推察された(Fig. 2,Table 3).

著者

村上 洋 瀬古 亜紀子 安積 真澄 上嶋 夏子 吉栖 肇 中野 博文 北畑 寿美雄

出版者

日本応用糖質科学会

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.50, no.2, pp.117-120, 2003

被引用文献数

4 36

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ラクトビオン酸(LA)はラクトースから合成されるアルドビオン酸で,ビフィズス菌増殖活性をもち,溶解性の高いミネラル補給剤として利用可能であるなど,用途に富んだ糖質素材である.しかし,現在までは,実用に耐える大量生産方法がなく,日本では化学合成法により試薬として少量市販されているのみであった.筆者らは,ラクトビオン酸の安価な大量生産方法の開発をめざし,Burkholderia cepaciaの1菌株を用いた発酵生産条件を検討した.その結果,回分培養では,4日間の培養により,2009/Lのラクトビオン酸が生成した.また乳糖と炭酸カルシウムの逐次添加を行う流加培養では,10日間の培養により,培養液中に4009/Lのラクトビオン酸を蓄積した.いずれの場合も,原料の加水分解や副生成物の生成を伴わず,収率は100%であった.得られた発酵培養液上清にエタノールを加えエタノール濃度75%とすることで,純度100%のLAが収率98%で得られた.

著者

宮永 顕正 小関 卓也 松澤 洋 若木 高善 祥雲 弘文 伏信 進矢

出版者

日本応用糖質科学会

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.53, no.2, pp.143-148, 2006 (Released:2006-07-20)

参考文献数

24

被引用文献数

1 2

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アラビノキシランは,植物細胞壁の成分の一つであり,β-1,4キシラン主鎖にα-1,2またはα-1,3結合でアラビノースが側鎖として結合している構造をとっている.α-L-アラビノフラノシダーゼは,そのアラビノキシランのキシラン主鎖と側鎖アラビノース間の結合を切断する酵素である.Aspergillus kawachii由来のα-L-アラビノフラノシダーゼB (AkAbf54) は,構造未知である糖質分解酵素ファミリー54に属しており,反応機構なども不明であった.われわれはこのAkAbf54のX線結晶構造解析を行った.AkAbf54をPichia pastorisで大量発現させ,結晶構造解析を行った.全体構造を明らかにしたところ,AkAbf54は触媒ドメインとアラビノース結合ドメインの二つのドメインから構成されていた.アラビノースとの複合体構造では,アラビノースが触媒ドメインに1分子,アラビノース結合ドメインに2分子結合していた.複合体構造および変異体を用いた実験などから,求核残基がGlu221,酸/塩基触媒がAsp297であることを明らかにした.興味深いことに隣り合ったシステイン残基Cys176およびCys177がジスルフィド結合を形成し,アラビノースを疎水的に認識していた.アラビノース結合ドメインは,糖質結合ドメイン (CBM) ファミリー13と似たフォールドをとっていた.しかし,糖リガンド結合部位やモチーフが異なるなどいくつか異なる点がみられた.これらのことを考慮に入れた結果,アラビノース結合ドメインは新規な糖質結合ドメインであるCBM42に分類された.われわれはCBM42の詳細な機能解析を行い,CBM42はヘミセルロースの側鎖の糖であるアラビノースのみを認識して結合するという,これまでには例のない新規な糖質結合ドメインであることを示した.

著者

清水 哲哉 中津 亨 宮入 一夫 奥野 智旦 加藤 博章

出版者

日本応用糖質科学会

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.51, no.2, pp.161-167, 2004 (Released:2008-03-24)

参考文献数

28

被引用文献数

1 2

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エンドポリガラクツロナーゼ(EndoPG)は,inverting型の加水分解酵素であり,その触媒機構の詳細は不明であった。本研究では,リンゴ銀葉病菌(Stereum purpureum)の病徴発現蛋白として単離されたEndoPG Iを用いて触媒機構の解明を目的としてX線結晶構造解析を行った。イオンスプレー型質量分析装置を用いたEndoPG Iの糖鎖修飾の分析結果からEndoPG Iの結晶化には,3種のアイソフォーム,EndoPG Ia,Ib,Icのうち糖鎖の最も少ないEndoPG IaをEndoHで糖鎖切断した脱糖鎖型EndoPG Iaを用いた。この脱糖鎖型EndoPG IaをPEG 4000を沈殿剤に用いたハンギングドロップ蒸気拡散法により結晶化した。得られた結晶は,空間群P1に属し,格子定数はa=37.26 Å,b=46.34 Å,c=52.05 Å,α=67.17°,β=72.44°,γ=68.90°であった。この結晶を用いて大型放射光施設SPring-8によりX線回折実験を行った。結晶構造の決定は,多波長異常分散法で行った。SPring-8で収集したデータを用いて初期位相を決定し,最終的に0.96 Å分解能でR値11.4%,Rfree値14.0%という超高分解能のEndoPG Iの構造モデルを得た。得られたEndoPG Iの構造は,10回の完全ターンの平行β-へリックス構造であった。さらに反応生成物であるガラクツロン酸(GalA)を1分子を含むbinary複合体と2分子含むternary複合体の結晶構造を1.00 Åおよび1.15 Å分解能で決定した。binary複合体において1分子のピラノース型(GalpA)の結合がみられた。GalpAの結合位置は,活性残基と推定されているAsp153,Asp173,Asp174の還元末端側にあたることから,GalpAは+1サブサイトに結合していると考えられた。一方,ternary複合体においては,GalpAの他に,フラノース型のGalfAの結合がみられた。GalfAの結合位置は,活性残基の非還元末端側にあたる-1サブサイトと決定された。+1サブサイトでは,三つの塩基性残基,His195,Arg226,Lys228がGalpAのカルボン酸の結合に関与していた。一方,-1サブサイトでは,特異なcis型のペプチド結合がGalfAのカルボン酸の認識に関わっていた。そこで,二つのガラクツロン酸の結合状態を基に,基質の-1,+1結合した2量体部分のモデルを構築し,EndoPG Iの反応機構を検討した。まず,Asp173は切断される基質モデルのグリコシド結合と直接水素結合しうる位置にあった。したがって,Asp173はグリコシド結合にプロトンを供給する一般酸触媒残基と確認された。一方,Asp153とAsp174は,基質のアノマー炭素を求核攻撃すると考えられる水分子と水素結合していた。このことから,Asp153あるいはAsp174が水からプロトンを引き抜き活性化する一般塩基触媒残基と予想された。

著者

Hiroki Hosaka Sayaka Shirai Sora Fujita Mitsuru Tashiro Takako Hirano Wataru Hakamata Toshiyuki Nishio

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.67, no.4, pp.129-135, 2020-11-20 (Released:2020-11-20)

参考文献数

24

被引用文献数

1

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Utilizing transglycosylation reaction catalyzed by β-N-acetylhexosaminidase of Stenotrophomonas maltophilia, β-D-fructofuranosyl-(2↔1)-α-N, N´diacetylchitobioside (GlcNAc2-Fru) was synthesized from N-acetylsucrosamine and N, N´-diacetylchitobiose (GlcNAc2), and β-D-fructofuranosyl-(2↔1)-α-N, N´, N´´-triacetylchitotrioside (GlcNAc3-Fru) was synthesized from GlcNAc2-Fru and GlcNAc2. Through purification by charcoal column chromatography, pure GlcNAc2-Fru and GlcNAc3-Fru were obtained in molar yields of 33.0 % and 11.7 % from GlcNAc2, respectively. The structures of these oligosaccharides were confirmed by comparing instrumental analysis data of fragments obtained by enzymatic hydrolysis and acid hydrolysis of them with known data of these fragments.

著者

Tomonari Tanaka Ayane Matsuura Yuji Aso Hitomi Ohara

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.67, no.4, pp.119-127, 2020-11-20 (Released:2020-11-20)

参考文献数

33

被引用文献数

2

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Glycopolymers have attracted increased attention as functional polymeric materials, and simple methods for synthesizing glycopolymers remain needed. This paper reports the aqueous one-pot and chemoenzymatic synthesis of four types of glycopolymers via two reactions: the β-galactosidase-catalyzed glycomonomer synthesis using 4,6-dimetoxy triazinyl β-D-galactopyranoside and hydroxy group-containing (meth)acrylamide and (meth)acrylate derivatives as the activated glycosyl donor substrate and as the glycomonomer precursors, respectively, followed by radical copolymerization of the resulting glycomonomer and excess glycomonomer precursor without isolating the glycomonomers. The resulting glycopolymers bearing galactose moieties exhibited specific and strong interactions with the lectin peanut agglutinin as glycoclusters.

著者

Midori Umekawa Kaito Hamada Naoto Isono Shuichi Karita

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.67, no.4, pp.103-109, 2020-11-20 (Released:2020-11-20)

参考文献数

20

被引用文献数

6

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Hexokinases catalyze glucose phosphorylation at the first step in glycolysis in eukaryotes. In the budding yeast Saccharomyces cerevisiae, three enzymes for glucose phosphorylation have long been known: Hxk1, Hxk2, and Glk1. In this study, we focus on Emi2, a previously uncharacterized hexokinase-like protein of S. cerevisiae. Our data show that the recombinant Emi2 protein (rEmi2), expressed in Escherichia coli, possesses glucose-phosphorylating activity in the presence of ATP and Mg2+. It was also found that rEmi2 phosphorylates not only glucose but also fructose, mannose and glucosamine in vitro. In addition, we examined changes in the level of endogenous Emi2 protein in S. cerevisiae in the presence or absence of glucose and a non-fermentable carbon source. We found that the expression of Emi2 protein is tightly suppressed during proliferation in high glucose, while it is strongly upregulated in response to glucose limitation and the presence of a non-fermentable carbon source. Our data suggest that the expression of the endogenous Emi2 protein in S. cerevisiae is regulated under the control of Hxk2 in response to glucose availability in the environment.

著者

Feunai Agape Papalii Tautau Minoru Izumi Emiko Matsunaga Yujiro Higuchi Kaoru Takegawa

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.67, no.3, pp.87-93, 2020-09-03 (Released:2020-09-03)

参考文献数

36

被引用文献数

2

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α-L-Rhamnosidases (α-L-Rha-ases, EC 3.2.1.40) are glycosyl hydrolases (GHs) that hydrolyze a terminal α-linked L-rhamnose residue from a wide spectrum of substrates such as heteropolysaccharides, glycosylated proteins, and natural flavonoids. As a result, they are considered catalysts of interest for various biotechnological applications. α-L-rhamnose (6-deoxy-L-mannose) is structurally similar to the rare sugar α-L-mannose. Here we have examined whether microbial α-L-Rha-ases possess α-L-mannosidase activity by synthesizing the substrate 4-nitrophenyl α-L-mannopyranoside. Four α-L-Rha-ases from GH78 and GH106 families were expressed and purified from Escherichia coli cells. All four enzymes exhibited both α-L-rhamnosyl-hydrolyzing activity and weak α-L-mannosyl-hydrolyzing activity. SpRhaM, a GH106 family α-L-Rha-ase from Sphingomonas paucimobilis FP2001, was found to have relatively higher α-L-mannosidase activity as compared with three GH78 α-L-Rha-ases. The α-L-mannosidase activity of SpRhaM showed pH dependence, with highest activity observed at pH 7.0. In summary, we have shown that α-L-Rha-ases also have α-L-mannosidase activity. Our findings will be useful in the identification and structural determination of α-L-mannose-containing polysaccharides from natural sources for use in the pharmaceutical and food industries.

著者

Sora Yamaguchi Naoki Sunagawa Mikako Tachioka Kiyohiko Igarashi Masahirog Samejima

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.67, no.3, pp.79-86, 2020-09-03 (Released:2020-09-03)

参考文献数

22

被引用文献数

3

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Thermal inactivation of saccharifying enzymes is a crucial issue for the efficient utilization of cellulosic biomass as a renewable resource. Cellobiohydrolases (CBHs) are a kind of cellulase. In general, CBHs belonging to glycoside hydrolase (GH) family 6 (Cel6) act synergistically with CBHs of GH family 7 (Cel7) and other carbohydrate-active enzymes during the degradation of cellulosic biomass. However, while the catalytic rate of enzymes generally becomes faster at higher temperatures, Cel6 CBHs are inactivated at lower temperatures than Cel7 CBHs, and this represents a limiting factor for industrial utilization. In this study, we produced a series of mutants of the glycoside hydrolase family 6 cellobiohydrolase PcCel6A from the fungus Phanerochaete chrysosporium, and compared their thermal stability. Eight mutants from a random mutagenesis library and one rationally designed mutant were selected as candidate thermostable mutants and produced by heterologous expression in the yeast Pichia pastoris. Comparison of the hydrolytic activities at 50 and 60 °C indicated that the thermal stability of PcCel6A is influenced by the number and position of cysteine residues that are not involved in disulfide bonds.

著者

西本 友之

出版者

日本応用糖質科学会

雑誌

Journal of applied glycoscience (ISSN:13447882)

巻号頁・発行日

vol.53, no.1, pp.57-64, 2006-01-20

参考文献数

67

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Trehalose (&alpha;-Glc<i>p</i>-(1&harr;1)-&alpha;-Glc<i>p</i>) is widely distributed in nature such as microorganisms, insects, plants, and invertebrates. This sugar exists not only as an energy source but also as an important functionality-material that protects the organization from damage by various stresses such as drying, freezing, and osmotic pressure. Therefore, organisms have various trehalose-related enzymes that participate in degradation or synthesis of trehalose to adjust the concentration in response to the environment. In this study, we obtained trehalase, trehalose synthase or trehalose phosphorylase producing bacterium from soil or an already identified bacterium. The trehalose-related enzymes are classified from the catalyst style into three groups named the degradation, the intramolecular transglucosylation, and the intermolecular transglucosylation. Three enzymes we screened were different from other kinds of trehalose-related enzymes. In addition, we clarified some properties of these enzymes, and examined the synthesis of useful oligosaccharides. Trehalase, which hydrolyzes trehalose to glucose, was purified from the <i>Bacillus</i> sp. T3 cultures. Trehalose synthase, which catalyzes the interconversion of maltose and trehalose by intramolecular transglucosylation, was purified from cell-free extracts of <i>Pimelobacter</i> sp. R48 and the thermophilic bacterium <i>Thermus aquaticus</i> ATCC33923. Trehalose phosphorylase, which catalyzes the reversible phosphorolytic cleavage of trehalose, was purified from a cell-free extract of thermopholic anaerobe, <i>Thermoanaerobacter brockii</i> ATCC 35047. Trehalose synthase was useful for not only the synthesis of trehalose but also the production of trehalulose (1-<i>O</i>-&alpha;-<small>D</small>-glucopyranosyl-<small>D</small>-fructose) from sucrose. Moreover, a non-reducing disaccharide, &alpha;-galactosyl &alpha;-glucoside, was synthesized for the first time by trehalose phosphorylase using galactose as an acceptor.

著者

Yu Teshigahara Ikuko Kakizaki Wataru Hirao Kanji Tanaka Ryoki Takahashi

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.67, no.2, pp.63-66, 2020-05-20 (Released:2020-05-20)

参考文献数

17

被引用文献数

2

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Human urinary trypsin inhibitor (UTI) is a proteoglycan composed of one core protein covalently linked to one glycosaminoglycan, which is a low sulfated chondroitin 4-sulfate. It is used as an anti-inflammatory medicine based on the protease inhibitory activity of the core protein. However, functions of the chondroitin sulfate have not been clarified. Recently, we succeeded in remodeling the UTI chondroitin sulfate to hyaluronan to create hyaluronan hybrid UTI, without changing the core protein. Here, we investigated the effect of the remodeled chondroitin sulfate on the activities of serine proteases. Native UTI showed stronger protease inhibitory activity than hyaluronan hybrid UTI or hydrolyzed glycosaminoglycan UTI. Chondroitin 4-sulfate chains with a small peptide derived from the native UTI did not show any protease inhibitory activity. These results suggest that the chondroitin sulfate chain linked covalently to core protein enhances protease inhibitor activity of UTI although the chondroitin sulfate chain itself does not.

著者

Masakazu Ike Ken Tokuyasu

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2019_0019, (Released:2020-02-19)

被引用文献数

1

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The aim of this study was to investigate the effect of pH control by CO2 pressurization on the enzymatic hydrolysis of herbaceous feedstock in the calcium capturing by carbonation (CaCCO) process for fermentable sugar production. The pH of the slurry of 5% (w/w) Ca(OH)2-pretreated/CO2-neutralized rice straw could be controlled between 5.70 and 6.38 at 50 °C by changing the CO2 partial pressure (pCO2) from 0.1 to 1.0 MPa. A mixture of fungal enzyme preparations, namely, Trichoderma reesei cellulases/hemicellulases and Aspergillus niger β-glucosidase, indicated that pH 5.5–6.0 is optimal for solubilizing sugars from Ca(OH)2-pretreated rice straw. Enzymatic saccharification of pretreated rice straw under various pCO2 conditions revealed that the highest soluble sugar yields were obtained at pCO2 0.4 MPa and over, which is consistent with the expected pH at the pCO2 without enzymes and demonstrates the effectiveness of pH control by CO2 pressurization.

著者

Kiyohiko Igarashi Satoshi Kaneko Motomitsu Kitaoka Masahiro Samejima

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.67, no.2, pp.51-57, 2020-05-20 (Released:2020-05-20)

参考文献数

40

被引用文献数

2

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Cellobiose dehydrogenase (CDH) is a flavocytochrome catalyzing oxidation of the reducing end of cellobiose and cellooligosaccharides, and has a key role in the degradation of cellulosic biomass by filamentous fungi. Here, we use a lineup of glucose/xylose-mixed β-1,4-linked disaccharides and trisaccharides, enzymatically synthesized by means of the reverse reaction of cellobiose phosphorylase and cellodextrin phosphorylase, to investigate the substrate recognition of CDH. We found that CDH utilizes β-D-xylopyranosyl-(1→4)-D-glucopyranose (Xyl-Glc) as an electron donor with similar Km and kcat values to cellobiose. β-D-Glucopyranosyl-(1→4)-D-xylopyranose (Glc-Xyl) shows a higher Km value, while xylobiose does not serve as a substrate. Trisaccharides show similar behavior; i.e., trisaccharides with cellobiose and Xyl-Glc units at the reducing end show similar kinetics, while the enzyme was less active towards those with Glc-Xyl, and inactive towards those with xylobiose. We also use docking simulation to evaluate substrate recognition of the disaccharides, and we discuss possible molecular mechanisms of substrate recognition by CDH.

著者

Atsushi Kawano Kansuke Fukui Yuji Matsumoto Atsushi Terada Akihiro Tominaga Nozomi Nikaido Takashi Tonozuka Kazuhide Totani Nozomu Yasutake

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2019_0015, (Released:2020-03-06)

被引用文献数

9

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According to whole-genome sequencing, Aspergillus niger produces multiple enzymes of glycoside hydrolases (GH) 31. Here we focus on a GH31 α-glucosidase, AgdB, from A. niger. AgdB has also previously been reported as being expressed in the yeast species, Pichia pastoris; while the recombinant enzyme (rAgdB) has been shown to catalyze tranglycosylation via a complex mechanism. We constructed an expression system for A. niger AgdB using Aspergillus nidulans. To better elucidate the complicated mechanism employed by AgdB for transglucosylation, we also established a method to quantify glucosidic linkages in the transglucosylation products using 2D NMR spectroscopy. Results from the enzyme activity analysis indicated that the optimum temperature was 65 °C and optimum pH range was 6.0–7.0. Further, the NMR results showed that when maltose or maltopentaose served as the substrate, α-1,2-, α-1,3-, and small amount of α-1,1-β-linked oligosaccharides are present throughout the transglucosylation products of AgdB. These results suggest that AgdB is an α-glucosidase that serves as a transglucosylase capable of effectively producing oligosaccharides with α-1,2-, α-1,3-glucosidic linkages.

著者

Hiromi Takada Takane Katayama Toshihiko Katoh

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2019_0020, (Released:2020-02-19)

被引用文献数

11

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Ovomucin, a hen egg white protein, is characterized by its hydrogel-forming properties, high molecular weight, and extensive O-glycosylation with a high degree of sialylation. As a commonly used food ingredient, we explored whether ovomucin has an effect on the gut microbiota. O-Glycan analysis revealed that ovomucin contained core-1 and core-2 structures with heavy modification by N-acetylneuraminic acid and/or sulfate groups. Of the two mucin-degrading gut microbes we tested, Akkermansia muciniphila grew in medium containing ovomucin as a sole carbon source during a 24 h culture period, whereas Bifidobacterium bifidum did not. Both gut microbes, however, degraded ovomucin O-glycans and released monosaccharides into the culture supernatants in a species-dependent manner, as revealed by semi-quantified mass spectrometric analysis and anion exchange chromatography analysis. Our data suggest that ovomucin potentially affects the gut microbiota through O-glycan decomposition by gut microbes and degradant sugar sharing within the community.

著者

笹川 秋彦 内木 由美子 長島 誠一 山倉 美穂 山崎 彬 山田 明文

出版者

日本応用糖質科学会

雑誌

Journal of applied glycoscience (ISSN:13447882)

巻号頁・発行日

vol.53, no.1, pp.27-33, 2006-01-20

参考文献数

27

被引用文献数

17

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Brown rice is commonly considered to have an effect on various diseases including life-style related diseases. Pre-germinated brown rice is characterized by its easier cooking properties and better taste after cooking when compared with normal brown rice. Because of the rich content of gamma-aminobutyric acid (GABA) in brown rice, which can prevent the increase of blood pressure, the market for brown rice is now growing. However, the taste of the cooked pre-germinated brown rice is still unsatisfactory because of the peculiar smell. We performed a study aimed at establishing a processing method for obtaining a brown rice product with more GABA accumulation than in the commercially available brown rice products by introducing a high-pressure treatment. The result was that the content of GABA in the obtained brown rice is higher than that in the commercially available brown rice products and the functional components such as ferulic acids and oryzanol are also retained. Further, such brown rice with increased GABA accumulation was found to be digested more quickly than the commercially available brown rice products when those cooked rice products were evaluated by the artificial digestion method. The GABA-increased brown rice was also found to compare favorably with commercially available normal brown rice in terms of taste after cooking.

著者

Sosyu Tsutsui Kiyoshi Sakuragi Kiyohiko Igarashi Masahiro Samejima Satoshi Kaneko

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.67, no.1, pp.17-22, 2020-02-20 (Released:2020-02-20)

参考文献数

29

被引用文献数

4

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Sugarcane bagasse is a useful biomass resource. In the present study, we examined the efficacy of ammonia pretreatment for selective release of hemicellulose from bagasse. Pretreatment of bagasse with aqueous ammonia resulted in significant loss of xylan. In contrast, pretreatment of bagasse with anhydrous ammonia resulted in almost no xylan loss. Aqueous ammonia or anhydrous ammonia-pretreated bagasse was then subjected to enzymatic digestion with a xylanase from the glycoside hydrolase (GH) family 10 or a xylanase from the GH family 11. The hydrolysis rate of xylan in bagasse pretreated with aqueous ammonia was approximately 50 %. In contrast, in the anhydrous ammonia-treated bagasse, xylan hydrolysis was > 80 %. These results suggested that anhydrous ammonia pretreatment would be an effective method for preparation of sugarcane bagasse for enzymatic hydrolysis to recover xylooligosaccharides.

著者

Yuya Furushiro Takashi Kobayashi

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2019_0014, (Released:2019-10-29)

被引用文献数

9

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Glucose and fructose were treated in subcritical water in the presence of alkali or alkaline earth metal chlorides. All salts accelerated the conversion of saccharides, and alkaline earth metal chloride greatly promoted the isomerization of glucose to fructose. In contrast, alkali metal salts only slightly promoted this isomerization and facilitated the decomposition of glucose to byproducts such as organic acids. The selectivity of the glucose-to-fructose isomerization was higher at lower conversions of glucose and in the presence of alkaline earth metal chlorides. The pH of the reaction mixture also greatly affected the selectivity, which decreased rapidly at lower pH due to the generated organic acids. At low pH, decomposition of glucose became dominant over isomerization, but further conversion of glucose was suppressed. This result was elucidated by the suppression of the alkali-induced isomerization of glucose at low pH. Fructose underwent decomposition during the treatment of the fructose solution, but its isomerization to glucose was not observed. The added salts autocatalytically promoted the decomposition of fructose, and the reaction mechanism of fructose decomposition differed from that of glucose.

著者

Ken Fukami Daiki Suehiro Motoko Ohnishi

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2019_0013, (Released:2019-10-30)

被引用文献数

8

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We examined the in vitro digestibility of maltobionic acid, obtained from enzymatic oxidation of maltose, its utilization by intestinal bacteria, and its biological effects on the bowel movements in healthy subjects. We found that maltobionic acid is not digested in vitro by saliva, gastric juice, or pancreatic juice. Moreover, it is digested only to a small extent by small intestinal enzymes. Among the 24 strains of intestinal bacteria, maltobionic acid was selectively utilized by Bifidobacterium dentium and Bi. adolescentis. We also evaluated the influence of long-term ingestion of maltobionic acid calcium salt on bowel movements in healthy Japanese women by a randomized, double-blind, placebo-controlled, crossover trial. Thirty-four subjects completed the study, and no adverse events related to the test food were observed. Ten subjects were excluded prior to the efficacy analysis because of conflict with the control criteria; the remaining 24 subjects were analyzed. Intake of test food containing 4 g maltobionic acid for 4 weeks caused a significant increase in the stool frequency, significant improvement in stool form scale and CAS-MT total scores as compared with the placebo group. These results suggest that maltobionic acid is an indigestible carbohydrate and is a promising therapeutic agent for improving the intestinal environment.

著者

Takae Nagasawa Katsuyuki Sato Takafumi Kasumi

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2019_0012, (Released:2019-10-24)

被引用文献数

6

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Lactulose, a keto-type disaccharide widely used in pharmaceuticals and functional foods, is produced by the isomerization of lactose. The organogermanium compound poly-trans-[(2-carboxyethyl) germasesquioxane] (Ge-132) is an effective reaction promoter for the conversion of lactose to lactulose because of its high affinity to ketoses. Herein, an effective method for the continuous production of lactulose syrup was developed using Ge-132 through the alkaline isomerization of lactose in a bench-scale plant. This plant carried out a continuous isomerization process using Ge-132, continuous two-step separation process for separating the sugar and Ge-132, a continuous purification and concentration processes for the lactulose syrup, and separation and purification processes for the recovery of Ge-132. In this bench-scale plant, lactulose-containing syrup (350 g/L lactulose, 92 g/L lactose, and 31 g/L galactose) was prepared. The syrup was produced at a rate of 37.7 mL/h, and the content of residual Ge-132 in the syrup was 2 mg/L. The separation process was a two-step separation system requiring an ordinary electrodialyzer and an electro deionizer, which allowed the separation of more than 99.6 % Ge-132 from the reaction mixture. Moreover, the majority of Ge-132 and sodium hydroxide were recovered through electrodialysis using a bipolar membrane. The proposed system is the first to represent the novel development of an effective continuous production system for lactulose-containing syrup on the basis of the use of organogermanium compounds and incorporation of the electrodialysis technology.