4- nitrophenyl-a-D-galactopyranoside

Photochemical nucleophilic aromatic substitution 4-Nitrophenyl-a-D- galactopyranoside... 

Purify 4-nitrophenyl-a-D-galactopyranoside by recrystallisation from H2O or aqueous EtOH. The monohydrate has m 85° which resolidifies and melts again at 151-152° (the hemihydrate), then resolidifies again and melts at 173° to give the ou/zyr/roMS form. Drying the monohydrate at 60° yields the hemihydrate, and drying at 100°... 

A neoagarobiase activity isolated from Pseudomonas atlantica hydrolysed 4-nitrophenyl a-D-galactopyranoside and neoagarotetraose, and was stimulated by Na " ions. ... 

Lactose 6 -0-sulphate neither behaved as a substrate nor acted as an inhibitor with respect to unsubstituted lactose and 4-nitrophenyl /3-D-galactopyranoside when tested with j3-D-galactosidase ( lactase ) of suckling rat intestine and Escherichia coli 3-D-galactosidase. ... 

Previously reported differences in the substrate specificities of a-D-galacto-sidases A and B from human liver have been further investigated. A highly purified fraction of the B enzyme was found to contain -D-2-acetamido-2-deoxygalactosidase activity Kja 2-nitrophenyl 2-acetamido-2-deoxy-a-D-galactopyranoside 1.3 mM, ATm 4-methylumbelliferyl a-D-galactopyranoside 6.8 mM) (see also p. 379). 

Employing a multichannel PDMS microreactor [350 gm (wide) x 250 gm (deep) x 6.4 mm (long)], in which the thermophilic enzyme (3-glycosi-dase was immobilized, Thomsen et al. (2007) evaluated the hydrolysis of 2-nitrophenyl-p-D-galactopyranoside. Heating the reactor to 80 °C, the authors were able to continuously hydrolyze 2-nitrophenyl-p-D-galactopyranoside and monitored the reaction efficiency via generation of 2-nitrophenol 97. 

Application and Principle This procedure is used to determine lactase activity of enzyme preparations derived from Aspergillus oryzae var. The assay is based on a 15-min hydrolysis of an o-nitrophenyl-(3-D-galactopyranoside substrate at 37° and pH 4.5. 

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