Hironobu Tsuchida

Chemical Studies on the Reaction Products of Glucose and Ammonia Part X:Isolation and Identification of 4 (5)-(DL-Glycero-2, 3-Dihydroxypropyl) imidazole

A new imidazole compound was isolated as crystalline form from the reaction mixture of glucose and ammonia, and identified as 4(5)-(dl-glycero-2,3-dihydroxypropyl)imidazole. From the results the authors suggested that pentose may be formed in the reaction mixture not by direct fission of C-C bond of glucose but by recombination of glucose fragments, for example, of triose and glycolic aldehyde.4(5)-[d-(-)-Glycero-2,3-dihydroxypropyl]imidazole was also newly prepared from d-xylose via 3-deoxy-d-pentosone.

Sugars in the Nondialyzable Melanoidin

アンモニアカラメルの一製造条件に従って,グルコースとアンモニアから調製した非透析性メラノイジンおよび,それをさらにDEAE-セルロースカラムによって分画したメラノイジン(F2, F3, F4, F5およびF6)中に存在する糖類について,各種検討を行なった. 1)該メラノイジンの酸加水分解物をAmberlite IR-120 (H+型)処理,ついで活性炭処理してえた画分Aについて, PPCおよびGLCによって検討を行なった.その結果,この画分の大部分は糖類であり,グルコース,フラクトース,アラビノースのほかに,痕跡量の4種の未知物質の存在が認められた. 2)該メラノイジンの酸加水分解の最適条件を検索した.その結果, 0.1N塩酸中, 1000°C, 7時間加熱した条件が比較的好ましい水解条件であることがわかった.また,水解最適条件の検索中,水中で該メラノイジンを煮沸しただけでも,全糖量の約1/2量の還元性糖類が遊離してくることがわかった.このことから全糖の約1/2の糖類は,該メラノイジン中でゆるい結合をなしているものと予想される. 3)各々のメラノイジン中の全糖量,および各種糖類の定量を行なった.全糖量はPark-Johnson法で,各種糖類についてはTMS誘導体として, GLC(内部標準法)で定量した.その結果,全糖の含量はいずれのメラノイジン中にも2～3%存在し,各々のメラノイジンのO/C値と糖量との間に,なんら相関性はみとめられなかった.また,各種糖類の定量の結果,いずれのメラノイジン中にもグルコースが圧倒的に多く含まれていたが,グルコース含量の最も多いのは, F2であった.また, F3およびF4はフラクトースが, F5ではアラビノースが比較的多く含まれていた.これらの結果から,各々のメラノイジンの生成順位(F2, F3, F4, F5の順で生成)が予想される.

Chemical Studies on the Reaction Products of Methylpentose and Ammonia:Part II. Formation of 4 (5)-Ethylimidazole from the Reaction of L-Rhamnose and Ammonia

Reducing sugars react in aqueous ammonia to form several imidazolic compounds. An unknown compound was newly isolated from the reaction mixture of l-rhamnose and ammonia, and identified as 4(5)-ethylimidazole. It was found that this compound was formed in aqueous ammonia only from such reducing sugars as rhamnose, fucose etc. containing a terminal methyl group. Consequently, it was inferred that in aqueous ammonia l-rhamnose decomposes to form ethylglyoxal as an intermediate of 4(5)- ethylimidazole.

The Oligosaccharides Produced from Sucrose by Dematium pullulans: Part I. Isolation and Characterization of a Tetrasaccharide

A tetrasaccharide produced from sucrose by Dematium pullulans was obtained in a crystalline state, and its properties and physical constants were studied. By elementary analysis, molecular weight, tetrazolium test, the Raybin test, aldose value, paper chromatographic examination of partial acid hydrolyzate and enzymic hydrolyzate, periodate oxidation, and molar optical rotation, the crystalline compound was identified as β-fructofuranosyl-1-kestose trihydrate.

A Modified Procedure for the Synthesis of Sucrose: Condensation of 1,3,4,6-Tetra-O-benzoyl-d-fructofuranose with 1,2-Anhydro-3,4,6-tri-O-acetyl-α-d-glucopyranose

A modified procedure for synthesis of sucrose was carried out by using purified crystalline 1,3,4,6-tetra-O-benzoyl-d-fructofuranose in place of 1,3,4,6-tetra-O-acetyl-d-fructofuranose; namely, reaction of 1,2-anhydro-3,4,6-tri-O-acetyl-α-d-glucopyranose with tetrabenzoyl-d-fructose at 110~118°C for 3 hr followed by deacylation, and by chromatographic separation of the deacylated product afforded crude sucrose. Acetylation of the synthetic product gave octaacetate sucrose in the yield of 5.0%.