335193-88-9

Usage

Uses

p-Nitrophenyl-β-D-melibiose (cas# 335193-88-9) is a compound useful in organic synthesis.

Upstream product

• 2492-87-7 4-nitrophenyl-β-D-glucoside 
• 2106-10-7 1-deoxy-1-fluoro-α-D-glucose 
• 3767-28-0 4-nitrophenyl-α-D-glucopyranoside 
• 447-27-8 β-D-glucopyranosyl fluoride 
• 69-79-4 D-maltose 
• 55722-48-0 methyl 2,3,4,6-tetra-O-acetyl-1-thio-β-D-galactopyranoside 
• 4163-60-4 β-D-galactose peracetate 
• 62847-72-7 4-nitrophenyl 2,3-di-O-acetyl-β-D-galactopyranoside 
• 108-24-7 acetic anhydride 
• 80321-97-7 p-nitrophenyl 6-O-β-D-galactopyranosyl-3,4-O-isopropylidene-β-D-galactopyranoside 
• 7512-17-6 N-Acetyl-D-glucosamine 
• 3150-24-1 4-nitrophenyl-β-D-galactopyranoside 
• 2492-87-7 p-nitrophenyl β-D-mannopyranoside 
• 7493-95-0 4-nitrophenyl α-D-galactoside 

Downstream Products

• 80373-95-1 p-nitrophenyl 2,3,4-tri-O-acetyl-6-O-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl)-β-D-galactopyranoside 

Relevant academic research and scientific papers

On expanding the repertoire of glycosynthases: Mutant β-galactosidases forming β-(1,6)-linkages

Oligosaccharide synthesis by enzymatic processes offers the potential for thrusting oligosaccharides to the forefront of pharmaceutical research, in part, due to expedient and scalable reaction protocols. Glycosynthases are an emerging class of mutant enzymes capable of synthesizing glycosidic linkages in high yield. We report a new glycosynthase enzyme generated by a point mutation of E. coli β-galactosidase that condenses α-galactosyl fluoride with aryl glucosides forming a β-(1,6) glycosidic linkage. A further point mutation within the enzyme, proximal to the active site, increases the yields significantly.

Galactosyl transfer onto p-nitrophenyl beta-D-glucoside using beta-D-galactosidase from Bacillus circulans.

beta-D-Gal-(1-->4)-beta-D-Glc-OC6H4NO2-p and its isomers (beta-D-Gal-(1-->3)-beta-D-Glc-OC6H4NO2-p and beta-D-Gal-(1-->6)-beta-D-Glc-OC6H4NO2-p) were synthesized from lactose and beta-D-Glc-OC6H4NO2-p, using transglycosylation by the beta-D-galactosidase from Bacillus circulans. This reaction was efficient enough for us to do a one-pot preparation of galactosyl-glucoside from lactose. The order of the production of the transfer products was (1-->4) > > (1-->3) > (1-->6) in the initial stage of the reaction, and the same relationship was observed for the hydrolytic rate toward the three galactosyl-glucosides. The production of (1-->4)- and (1-->3)-linkages greatly decreased during the subsequent reaction and much more of the (1-->6)- than of the (1-->4)- and (1-->3)-transfer products was found in the later stage of the reaction.

Characterization of properties and transglycosylation abilities of recombinant α-galactosidase from cold-adapted marine bacterium pseudoalteromonas KMM 701 and its C494N and D451A mutants

A novel wild-type recombinant cold-active α-D-galactosidase (α-PsGal) from the cold-adapted marine bacterium Pseudoalteromonas sp. KMM 701, and its mutants D451A and C494N, were studied in terms of their structural, physicochemical, and catalytic properties. Homology models of the three-dimensional α-PsGal structure, its active center, and complexes with D-galactose were constructed for identification of functionally important amino acid residues in the active site of the enzyme, using the crystal structure of the α-galactosidase from Lactobacillus acidophilus as a template. The circular dichroism spectra of the wild α-PsGal and mutant C494N were approximately identical. The C494N mutation decreased the efficiency of retaining the affinity of the enzyme to standard p-nitrophenyl-α-galactopiranoside (pNP-α-Gal). Thin-layer chromatography, matrix-assisted laser desorption/ionization mass spectrometry, and nuclear magnetic resonance spectroscopy methods were used to identify transglycosylation products in reaction mixtures. α-PsGal possessed a narrow acceptor specificity. Fructose, xylose, fucose, and glucose were inactive as acceptors in the transglycosylation reaction. α-PsGal synthesized -α(1→6)- and -α(1→4)-linked galactobiosides from melibiose as well as -α(1→6)- and -α(1→3)-linked p-nitrophenyl-digalactosides (Gal2-pNP) from pNP-α-Gal. The D451A mutation in the active center completely inactivated the enzyme. However, the substitution of C494N discontinued the Gal-α(1→3)-Gal-pNP synthesis and increased the Gal-α(1→4)-Gal yield compared to Gal-α(1→6)-Gal-pNP.

Efficient synthesis of α-galactosyl oligosaccharides using a mutant Bacteroides thetaiotaomicron retaining α-galactosidase (BtGH97b)

The preparation of a glycosynthase, a catalytic nucleophile mutant of a glycosidase, is a well-established strategy for the effective synthesis of glycosidic linkages. However, glycosynthases derived from α-glycosidases can give poor yields of desired products because they require generally unstable β-glycosyl fluoride donors. Here, we investigate a transglycosylation catalyzed by a catalytic nucleophile mutant derived from a glycoside hydrolase family (GH) 97 α-galactosidase, using more stable β-galactosyl azide and α-galactosyl fluoride donors. The mutant enzyme catalyzes the glycosynthase reaction using β-galactosyl azide and α-galactosyl transfer from α-galactosyl fluoride with assistance of external anions. Formate was more effective at restoring transfer activity than azide. Kinetic analysis suggests that poor transglycosylation in the presence of the azide is because of low activity of the ternary complex between enzyme, β-galactosyl azide and acceptor. A three-dimensional structure of the mutant enzyme in complex with the transglycosylation product, β-lactosyl α-d-galactoside, was solved to elucidate the ligand-binding aspects of the α-galactosidase. Subtle differences at the β→α loops 1, 2 and 3 of the catalytic TIM barrel of the α-galactosidase from those of a homologous GH97 α-glucoside hydrolase seem to be involved in substrate recognitions. In particular, the Trp residues in β→α loop 1 have separate roles. Trp312 of the α-galactosidase appears to exclude the equatorial hydroxy group at C4 of glucosides, whereas the corresponding Trp residue in the α-glucoside hydrolase makes a hydrogen bond with this hydroxy group. The mechanism of α-galactoside recognition is conserved among GH27, 31, 36 and 97 α-galactosidases. Database: The atomic coordinates (code: 5E1Q) have been deposited in the Protein Data Bank.

Preparation of α-galactooligoglycosides by cell walls from Cryptococcus laurentii using a novel α-galactosyl donor

The cell walls of an acapsular strain of the yeast Cryptococcus laurentii catalyze the regioselective formation of α-galactooligosaccharides through self-condensation of 4-nitrophenyl α-D-galactopyranoside and of a novel activated α-galactosyl donor 2,2,2-trifluoroethyl α-D-galactopyranoside. The latter substance can be easily prepared by several methods and is highly soluble in water and therefore can be used in higher initial concentrations suppressing secondary product hydrolysis. The preparative reaction catalyzed by cell walls provided 17.4% and 2% of corresponding 2,2,2-trifluoroethyl galactobioside and galactotrioside, respectively, while the reaction with 4-nitrophenyl α-D-galactopyranoside provided the corresponding 4-nitrophenyl galactobioside and galactotrioside in 6.6 and 2.5% yields, respectively. The reactions proceeded with strict α-(1 → 6)-regioselectivity.

Acceptor-induced modification of regioselectivity in CGTase-catalyzed glycosylations of p-nitrophenyl-glucopyranosides

Cyclodextrin glycosyltransferases (CGTase) are reported to selectively catalyze α(1→4)-glycosyl transfer reactions besides showing low hydrolytic activity. Here, the effect of the anomeric configuration of the glycosyl acceptor on the regioselectivity of

A novel, efficient and sustainable strategy for the synthesis of α-glycoconjugates by combination of a α-galactosynthase and a green solvent

Glycosynthases are becoming important enzymatic tools for the synthesis of oligosaccharides. Herein, we explore for the first time the synthesis of α-glycoconjugates using a α-glycosynthase in green solvents. Using this biocatalyst, β-Gal-N3 as donor, pNP-Glc and pNP-Man as acceptors, and green co-solvents we obtained high yields and excellent selectivities in the synthesis of α-glycoconjugates. In addition, reaction scale-up is feasible and co-solvent can be recovered and reused, increasing the sustainability of the reaction process. The results demonstrate that the combination of a glycosynthase and a green solvent is a promising alternative for the synthesis of glycoconjugates. The non-hydrolytic capability of this enzyme on the product obtained is a key feature that can be expanded to other glycosynthases.

Semi-rational approach for converting a GH36 α-glycosidase into an α-transglycosidase

A large number of retaining glycosidases catalyze both hydrolysis and transglycosylation reactions. In order to use them as catalysts for oligosaccharide synthesis, the balance between these two competing reactions has to be shifted toward transglycosylat

α-Galactobiosyl units: Thermodynamics and kinetics of their formation by transglycosylations catalysed by the GH36 α-galactosidase from Thermotoga maritima

Broad regioselectivity of α-galactosidase from Thermotoga maritima (TmGal36A) is a limiting factor for application of the enzyme in the directed synthesis of oligogalactosides. However, this property can be used as a convenient tool in studies of thermodynamics of a glycosidic bond. Here, a novel approach to energy difference estimation is suggested. Both transglycosylation and hydrolysis of three types of galactosidic linkages were investigated using total kinetics of formation and hydrolysis of pNP-galactobiosides catalysed by monomeric glycoside hydrolase family 36 α-galactosidase from T. maritima, a retaining exo-acting glycoside hydrolase. We have estimated transition state free energy differences between the 1,2- and 1,3-linkage (ΔΔG?0 values were equal 5.34 ± 0.85 kJ/mol) and between 1,6-linkage and 1,3-linkage (ΔΔG?0 = 1.46 ± 0.23 kJ/mol) in pNP-galactobiosides over the course of the reaction catalysed by TmGal36A. Using the free energy difference for formation and hydrolysis of glycosidic linkages (ΔΔG?F - ΔΔG?H), we found that the 1,2-linkage was 2.93 ± 0.47 kJ/mol higher in free energy than the 1,3-linkage, and the 1,6-linkage 4.44 ± 0.71 kJ/mol lower.

α-Galactobiosyl units: Thermodynamics and kinetics of their formation by transglycosylations catalysed by the GH36 α-galactosidase from Thermotoga maritima

Broad regioselectivity of α-galactosidase from Thermotoga maritima (TmGal36A) is a limiting factor for application of the enzyme in the directed synthesis of oligogalactosides. However, this property can be used as a convenient tool in studies of thermodynamics of a glycosidic bond. Here, a novel approach to energy difference estimation is suggested. Both transglycosylation and hydrolysis of three types of galactosidic linkages were investigated using total kinetics of formation and hydrolysis of pNP-galactobiosides catalysed by monomeric glycoside hydrolase family 36 α-galactosidase from T. maritima, a retaining exo-acting glycoside hydrolase. We have estimated transition state free energy differences between the 1,2- and 1,3-linkage (ΔΔG?0 values were equal 5.34 ± 0.85 kJ/mol) and between 1,6-linkage and 1,3-linkage (ΔΔG?0 = 1.46 ± 0.23 kJ/mol) in pNP-galactobiosides over the course of the reaction catalysed by TmGal36A. Using the free energy difference for formation and hydrolysis of glycosidic linkages (ΔΔG?F - ΔΔG?H), we found that the 1,2-linkage was 2.93 ± 0.47 kJ/mol higher in free energy than the 1,3-linkage, and the 1,6-linkage 4.44 ± 0.71 kJ/mol lower.