Nitrophenylgalactosides → 2-Nitrophenol

HRID 493894

Reaction equation

HRID 493894 reaction equation
[C@@H]1(O[C@H](CO)[C@H](O)[C@@H](O)C=O)O[C@H](CO)[C@H](O)[C@H](O)[C@H]1O.[O:22]([C:34]1[CH:39]=[CH:38][CH:37]=[CH:36][C:35]=1[N+:40]([O-:42])=[O:41])[C@@H]1O[C@H](CO)[C@H](O)[C@H](O)[C@H]1O.O=C[C@@H]([C@H]([C@@H](CO)O)O)O.OP([O-])(O)=O.[K+].OP([O-])([O-])=O.[K+].[K+].[Mg+2].[Cl-].[Cl-].SC(O)C>O>[N+:40]([C:35]1[CH:36]=[CH:37][CH:38]=[CH:39][C:34]=1[OH:22])([O-:42])=[O:41]

Participants

8

Reactant 6

HCID 96647Nitrophenylgalactosides2×HCID 644160aldehydo-D-XyloseHCID 3082054GaxiloseHCID 4713212Mercapto-ethanolHCID 5360315Magnesium ChlorideHCID 21889592Monopotassium phosphate dipotassium phosphate

Product 1

HCID 69472-NitrophenolYield 19%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
100 °C

Procedure

In order to synthesize 4-O-β-D-galactopyranosyl-D-xylose, 5 g of o-nitrophenyl β-D-galactopyranoside (Gal-ONP) and 25 g of D-xylose were dissolved in 330 ml of water buffered to a pH of 7 (0.05 M KH2PO4/K2HPO4, 1 mM MgCl2, 5 mM mercaptoethanol), 2 mg (640 u) of E. coli β-galactosidase enzyme were added and the solution thus obtained was subjected to incubation at 37° C. in an orbital stirrer until the Gal-ONP was practically consumed (approximately 2 hours). Following the methodology put forth in example 3, the reaction was stopped by heating at 100° C. for 10 minutes and the ortho-nitrophenol formed was extracted with ethyl acetate. The aqueous solution was concentrated up to an approximate volume of 50 ml, filtered through glasswool and passed through the active carbon/celite column. First of all, the excess D-xylose was eluted with water and afterwards, using a fractioned gradient of EtOH/H2O (2%-10% of EtOH) the mixture of disaccharides was collected. The enriched fractions in the 4-O-β-D-galactopyranosyl-D-xylose regioisomer were combined and concentrated to a reduced volume, after which acetone was added until turbidity appeared and the mixture thus obtained was left to stand cold. The 4-O-β-D-galactopyranosyl-D-xylose was crystallized in a pure form, obtaining 970 mg, namely, a yield of 19% based on the initial Gal-ONP, whose spectral data coincided with those given for the product obtained in accordance with example 3.

Workup

  1. additioncoli β-galactosidase enzyme were added
  2. customthe solution thus obtained
  3. customwas practically consumed (approximately 2 hours)

Sources & evidence

ORD record
ord-f31e4a24244f4b069dacfd71bce1d912
Source dataset
uspto-grants-2009_05
Patent number
US07537909B2

Linked notes

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