Synthesis of 9-β-d-Glucopyranosyl-Adenine-6′-Phosphate

Synthesis of 9-β-d-glucopyranosyl-adenine-6′-phosphate is described. The method developed here involves the process of condensation of base (chloromercuri-6-benzamidopurine) (I) with phosphorylated sugar (2,3,4-tri-O-acetyl-6-diphenylphosphoryl-α-d-glucopyranosyl bromide) (II). This reaction gives crystalline 6-benzamido-9-(2′,3′,4′-tri-O-acetyl-6′-diphenylphosphoryl-β-d-glucopyranosyl)-purine (III) in high yield, which is converted to the desired nucleotide by alkaline hydrolysis.     

An Improved Synthesis of dl-Histidine

The 5-O-(2,6-diamino-2,6-dideoxy-α-d-glucopyranosyl)-2-deoxystreptamine derivative and its related compounds were synthesized by a modified Königs-Knorr condensation of 3,4-di-O-acetyl-2,6-dideoxy-2-(2′,4′-dinitroanilino)-6-phthalimido-α-d-glucopyranosyl bromide (I) with 4,6-di-O-acetyl-N,N′-dicarbobenzoxy-2-deoxystreptamine (V) and the corresponding streptamine (XI). The aglycons (V) and (XI) were prepared by selective acetylation of the aminocyclitol derivatives by taking advantage of the reactivity difference between the hydroxyl groups at C₅ and C₄ or C₆. The condensed products were converted to N-acetyl derivatives and were shown to have the α-configuration by PMR spectroscopy.     

A Growth Factor for Malo-lactic Fermentation Bacteria

A growth factor (TJF) for a malo-lactic fermentation bacterium has been isolated from tomato juice, and found to be a β-glucoside. The NMR spectra of TJF and its acetate revealed that the glucosyl residue linked to the hydroxyl group at C-2′ or C-4′ of d- or l-pantothenic acid moiety. Then, 2′-O-(β-d-glucopyranosyl)-dl-pantothenic acid (I), 4′-O-(β-d-glucopyranosyl)-dl-pantothenic acid (II) and 4′-O-(β-d-glucopyranosyl)-d(R)-pantothenic acid (II-a) were synthesized, and Il-a and 4′-O-(β-d-glucopyranosyl)-l-pantothenic acid (II-b) were obtained by the optical resolution of the acetate of II. Among the above compounds, II-a was identical with natural TJF regarding to the biological activity, NMR and ORD spectra, and thin-layer chromatography.     

Glycolipids Isolated from Spirulina maxima: Structure and Fatty Acid Composition

Several glycolipids were isolated from Spirulina maxima, an edible blue-green algae, by systematic fractionation with different solvents. Structural investigation by using methylation, GC-MS, and enzymic techniques indicated that the major glycolipids are O-β-d-galactosyl-(1→l′)-2′, 3′-di-O-acyl-d-glycerol, O-α-d-galactosyl-(l-→6)-O-β-d-galactosyl-(1→l′)-2′,3′-di-O-acyl-d-glycerol and 6-sulfo-O-α-quinovosyl-(l→l′)-2′, 3′-di-O-acyl-d-glycerol. Main fatty acid components of these glycolipids were identified as palmitic acid and linoleic or linolenic acid. Based on-these fatty acid compositions, Spirulina glycolipids were compared with those in higher plants.     

Studies on the d-Xylose Series

This paper deals with the partial correction of our previous paper and with some new results in regard to ammonolysis of the epoxide ring of 2,3-anhydroribofuranoside derivatives.

Treatment of methyl 2,3-anhydro-5-deoxy-α-d-ribofuranoside, prepared from d-xylose, with ammonia gave methyl 2-amino-2,5-dideoxy-α-d-arabinoside and no methyl 3-amino-3,5-dideoxy-α-d-xyloside which we reported to obtain previously.

The exclusive attack of the nucleophilic reagent at C-2 is inconsistent with a result of C. D. Anderson et al. in regard to ammonolysis of methyl 2,3-anhydro-α-d-ribofuranoside.

In contrast to α-anomer, methyl 2,3-anhydro-5-deoxy-β-d-ribofuranoside gave mainly methyl 3-amino-3,5-dideoxy-β-d-xyloside. The difference of ammonolysis products between α- and β-anomer will be due to existence of steric hindrance.     

Glycogen Synthetase from Pullularia pullulans

3,4-Di-O-acetyl-2,6-dideoxy-2-(2′,4′-dinitroanilino)-6-phthalimido-α-d-glucopyranosyl bromide (I) was prepared in a good yield from glucosamine hydrochloride. A modified Königs-Knorr condensation of this bromide with a 2-deoxysteptamine derivative afforded a neamine derivative (IX) and its diastereomer (X). These compounds, (IX) and (X), were identified by PMR spectroscopy after conversion into the corresponding N-acetyl derivatives, (XI) and (XII).     

A Bitter Principle of Asparagus: Isolation and Structure of Furostanol Saponin in Asparagus Storage Root

During an examination of components contributing to the bitter taste of asparagus bottom cut (Asparagus officinalis L.), two new furostanol saponins were isolated from roots extractives. Their chemical structures were established as 5β-furostane-3β,22,26 triol-3-O-β-d-glucopyranosyl (1→2)-β-d-glucopyranoside 26-O-β-d-glucopyranoside and 5β-furostane-3β,22,26 triol-3-O-β-d-glucopyranosyl (1→2) [β-d-xylopyranoxyl (1→4)]-β-d-glucopyranoside 26-O-β-d-glucopyranoside respectively.     

Syntheses of Some Derivatives of Glycosyl Pantothenic Acids,Analogues of Growth Factor for MLF Bacteria

A growth factor (TJF) for a malo-lactic fermentation bacterium (Leuconostoc sp.) has been found to be 4′-O-(β-D-glucopyranosyl)-D-pantothenic acid with structural and synthetical studies. Now other 4′-O-glycosides (β-D-ribofuranosyl, α-D-glucopyranosyl, β-D-galacto-pyranosyl, β-maltosyl and β-cellobiosyl) and 2′,4′-O-di-β-D-glucopyranoside of DL-pantothenic acid, and 4′-O-β-D-glucopyranoside of DL-pantethine were synthesized to examine their biological activities. The improved syntheses of TJF were also examined.     

Synthesis of Tropolone Glucopyranosides

Reactions of tropolone (1a) and 3-isopropenyl-, 3-acetyl-, 3- acetamido-, and 5-bromotropolones 1b-e with 2,3,4,6-tetra-O-acet- yl-α-d-glucopyranosyl bromide were carried out in the presence of silver carbonate at 80°C. Unsubstituted, 3′-/7′-isopropenyl-, 7′-acetyl-, 7′-acetamido-, and 5′-bromo-substituted 2′-troponyl 2,3,4,6-tetra-O-acetyl-β-d-glucopyranosides were respectively obtained.     

Synthesis of Some New α- and β-(l→2) Linked Disaccharides Containing L-Quinovose (6-Deoxy L-Glucose)

Hepta-O-acetyl-2-0-β-l-quinovopyranosyl-α-d-glucose (VI) and hepta-O-acetyl-2-O-α-l-quinovopyranosyl-β-d-gIucose (VIII) were prepared by the coupling of 2,3,4-tri-O-acetyl-α-l-quinovopyranosyl bromide (IV) with l,3,4,6-tetra-O-acetyl-α-D-glucose (V) in the presence of mercuric cyanide and mercuric bromide in absolute acetonitrile.

Similarly, hepta-O-acetyW-O-α-l-quinovopyranosyl-α-d-galactose (X) and hepta-O-acetyl-2-O-β-L-quinovopyranosyl-α-d-galactose (XI) were prepared by the reaction of IV with 1,3,4,6-tetra-O-acetyl-α-d-galactose (IX).

Removal of the protecting groups of VI, VIII, X and XI afforded the corresponding disaccharides. On treatment with hydrogen bromide, VI, VIII, X and XI gave the corresponding acetobromo derivatives.     

Synthesis and Properties of Isomeric Di- and Mono-Glucopyranosyl Hypoxanthines

Four isomeric glucosyl hypoxanthines, bis-1,9-(β-d-glucopyranosyl) hypoxanthine (I), bis-1,7-(β-d-glucopyranosyl) hypoxanthine (II), 7-β-d-glucopyranosyl hypoxanthine (III) and 9-β-d-glucopyranosyl hypoxanthine (IV) were synthesized simultaneously by using the so- called Davoll-Lowy’s method. Their synthetic procedures and structural evidences are presented.     

Nucleosides and Related Substances

A new procedure which involves 1-trichloroacetyl sugars as the starting material has been developed for the synthesis of purine nucleosides. 7-β-d-Glucopyranosyl-, 7-β-d-xylopyranosyl-, 7-β-d-ribopyranosyl-theophylline, 9-(tetra-O-acetyl-β-d-glucopyranosyl)-2,6,8-trichloropurine and 9-β-d-glucopyranosyl adenine were prepared in good yields by the reaction in fusion of purine bases with 1-trichloroacetyl sugars, using zinc chloride, p-toluenesulfonic acid, or ethyl polyphosphate as catalyst. 9-d-Ribofuranosyl adenine was also prepared by the same procedures, although the anomeric configuration of the compound is not yet definite. The effect of catalysts on the yields of purine nucleosides is discussed.     

Structural Studies on New,Non-reducing Oligosaccharides Produced by Rhizobium meliloti J7017

Three non-reducing oligosaccharides were isolated from the fraction of cyclic (1→2)-β-d-glucan of Rhizobium meliloti J7017 by reversed-phase chromatography and paper chromatography. Methylation and ¹H-NMR analyses indicated that they were α-d-glucopyranosyl α-kojitrioside, α-d-glucopyranosyl α-kojitetraoside, and α-d-glucopyranosyl α-kojipentaoside.     

Structure of Carbohydrate Moiety of Asterosaponin A

Partial acid hydrolysis of asterosaponin A, a steroidal saponin, afforded two new disaccharides in addition to O-(6-deoxy-α-d-glucopyranosyl)-(l→4)-6-deoxy-d-glucose which has been characterized in the preceding paper. The formers were demonstrated as O-(6-deoxy-α-d-galactopyranosyl)-(1→4)-6-deoxy-d-glucose and O-(6-deoxy-α-d-galactopyranosyl)-(l→4)-6-deoxy-d-galactose, respectively.

Accordingly, the structure of carbohydrate moiety being composed of two moles each of 6-deoxy-d-galactose and 6-deoxy-d-glucose, was established as O-(6-deoxy-α-d-galactopyranosyl)-(l→4)-O-(6-deoxy-α-d-galactopyranosyl)-(l→4)-O-(6-deoxy-α-d-glucopyranosyl)-(l→4)-6-deoxy-d-glucose, which is attached to the steroidal aglycone through an O-acetal glycosidic linkage.     

Effects of Metal Ions on Cattle Liver Phosphoenolpyruvate Carboxykinase Activity in Vitro

A plant glycosphingolipid, O-(β-d-mannopyranosyl)-(l → 4)-O-(β-d-glucopyranosyl)-(l → l)-(2S,3S,4R)-4-hydroxy-N-tetracosanoylsphinganine 1, and the stereoisomer, O-(α-d-mannopyranosyl)-(1 → 4)-O-(β-d-glucopyranosyl)-(l → l)-(2S,3S,4R)-4-hydroxy-N-tetracosanoylsphinganine 6, were synthesized in a stereo- and regio-controlled way.     

Enzymatic Formation of d-Pantothemc Acid-β-Glucoside by Various β-Glucosidases

A β-gIucoside of d-pantothenic acid was formed from d-pantothenic acid and β-glucosyl donors such as cellobiose, phenyl-β-d-glucoside, salicin, and 4-methylumbelliferyl-β-d-glucoside and naphthol AS-BI-β-d-glucoside by various β-glucosidases, i.e., almond β-glucosidase, cellulase type II and III, naringinase, and hesperiginase. The compound was isolated from a reaction mixture of almond β-glucosidase by treatment with active charcoal, Amberlite CG–50, and DEAH-cellulose column chromatography, paper chromatography, and Sephadex G-IO gel filtration. Then, the compound was characterized as 4′-O-(β-d-glucopyranosyl)-d-pantothenic acid by various analytical methods including bioassay, paper chromatography, NMR and specific optical rotation. The microbiological activities of the compound were also determined.     

Biotransformation of Cinnamic Acid,p-Coumaric Acid,Caffeic Acid,and Ferulic Acid by Plant Cell Cultures of Eucalyptus perriniana

Biotransformations of phenylpropanoids such as cinnamic acid, p-coumaric acid, caffeic acid, and ferulic acid were investigated with plant-cultured cells of Eucalyptus perriniana. The plant-cultured cells of E. perriniana converted cinnamic acid into cinnamic acid β-D-glucopyranosyl ester, p-coumaric acid, and 4-O-β-D-glucopyranosylcoumaric acid. p-Coumaric acid was converted into 4-O-β-D-glucopyranosylcoumaric acid, p-coumaric acid β-D-glucopyranosyl ester, 4-O-β-D-glucopyranosylcoumaric acid β-D-glucopyranosyl ester, a new compound, caffeic acid, and 3-O-β-D-glucopyranosylcaffeic acid. On the other hand, incubation of caffeic acid with cultured E. perriniana cells gave 3-O-β-D-glucopyranosylcaffeic acid, 3-O-(6-O-β-D-glucopyranosyl)-β-D-glucopyranosylcaffeic acid, a new compound, 3-O-β-D-glucopyranosylcaffeic acid β-D-glucopyranosyl ester, 4-O-β-D-glucopyranosylcaffeic acid, 4-O-β-D-glucopyranosylcaffeic acid β-D-glucopyranosyl ester, ferulic acid, and 4-O-β-D-glucopyranosylferulic acid. 4-O-β-D-Glucopyranosylferulic acid, ferulic acid β-D-glucopyranosyl ester, and 4-O-β-D-glucopyranosylferulic acid β-D-glucopyranosyl ester were isolated from E. perriniana cells treated with ferulic acid.     

Syntheses of Paromamine and Its Related Compounds

Paromamine and its related compounds were synthesized by a modified Königs-Knorr reaction of 3,4,6-tri-O-acetyl-2-(2′,4′-dinitroanilno)-α-d-glucopyranosyl bromide with isopropylidene derivatives of 2-deoxystreptamine, streptamine and dihydroconduramine F–4. The condensed products were isolated as their poly N-acetyl derivatives and proved to have α-configuration by PMR spectroscopy in D₂O.     

Anti-Diabetic Effects of a Kaempferol Glycoside-Rich Fraction from Unripe Soybean (Edamame,Glycine max L. Merrill. ‘Jindai’) Leaves on KK-Ay Mice

The anti-diabetic effects of a kaempferol glycoside-rich fraction (KG) prepared from leaves of unripe Jindai soybean (Edamame) and kaempferol, an aglycone of kaempferol glycoside, were determined in genetically type 2 diabetic KK-A^y mice. The hemoglobin A_1c level was decreased and tended to be decreased by respectively feeding KG and kaempferol (K). The area under the curve (AUC) in the oral glucose tolerance test (OGTT) tended to be decreased by feeding K and KG. The liver triglyceride level and fatty acid synthase activity were both decreased in the mice fed with KG and K when compared to those parameters in the control mice. These results suggest that KG and K would be useful to improve the diabetes condition. The major flavonoids in KG were identified as kaempferol 3-O-β-D-glucopyranosyl(1→2)-O-[α-L-rhamnopyranosyl(1→6)]-β-D-galactopyranoside, kaempferol 3-O-β-D-glucopyranosyl(1→2)-O-[α-L-rhamnopyranosyl(1→6)]-β-D-glucopyranoside, kaempferol 3-O-β-D-(2-O-β-D-glucopyranosyl) galactopyranoside and kaempferol 3-O-β-D-(2,6-di-O-α-L-rhamnopyranosyl) galactopyronoside, suggesting that these compounds or some of them may be concerned with mitigation of diabetes.     

Conversion of Cellobiose into Lactose

Benzyl 2, 3, 6-tri-O-acetyl-4-O-(2,3-di-O-acetyl-4,6-di-O-methylsulfonyl-β-d-glucopyranosyl)-β-d-glucopyranoside (VI) was prepared from α-cellobiose octaacetate. Displacement of the sulfonyl esters of VI with acyloxy-groups in N, N-dimethyl formamide in the presence of sodium benzoate gave 4-O-β-d-galactopyranosyl-d-glucopyranose derivative (lactose derivative). Elimination of blocking groups of the derivative yielded lactose hydrate (IX), though the overall yield of lactose from cellobiose octaacetate was less than 2%.