Galactopyranoside phenyl

Methylumbelliferyl p-D-xylopyranoside ort/w-A itrophenyl P-D-galactopyranoside ortAn-A itrophenyl P-D-glucopyranoside para-Chlorophenyl P-D-mannopyranoside Phenyl P-D-galactopyranoside Phenyl P-D-glucopyranoside... 

Phenyl 0-D-mannopyranoaide Methyl /S-n-gulopyranoside Phenyl S-D-galactopyranoside ... 

M. Yde and C. K. De Bruyne, Binding of substituted phenyl 1-thio-P-D-galactopyranosides to P-D-galactosidase from E. coli, Carbohydr. Res., 60 (1978) 155-165. 

Fig. 3. Conversion of O-nitro-phenyl-P-D-galactopyranoside (ONPG) into O-nitrophenol and d-galactose as a function of time in packed (5- D-galactosidase-immobil-ized bed reactor operated isother-mally at 30 °C and 35 °C or cycled between 30 and 35 °C (From T.G. Park and A.S. Hoffman [63])...

Very efficient reaction occurs when phenyl 1 -thio-/ -D-glucopyranoside and -D-galactopyranoside tetrabenzoates (94 and 95) are treated in refluxing carbon tetrachloride with JV-bromosuccinimide under a heat lamp, and, within 15 minutes, they are converted into products from which the enones 96 and 97 have been obtained by direct crystallization in 76 and 83% yield, respectively (see Scheme 15).20... 

Since phenyl a-D-galactopyranoside did react, although slowly, it is apparent that this substance was converted to some intermediate common to it and the jS-D-galactopyranoside, or else it was degraded by a mechanism unique to itself. The conversion of phenyl /3-D-mannopyranoside to l,6-anhydro-/3-D-mannopyranose9 was effected with relative ease, whereas phenyl a-D-mannopyranoside reacted at about the same rate but the intermediate product, which was apparently not stabilized by 1,6-anhydride formation, underwent extensive destruction in the alkali.8... 

Those degradations which occur in spite of the unfavorable steric relationships within the molecule may proceed in either of two ways. The first is by a single-inversion mechanism. This has been suggested in order to rationalize the alkaline degradation of phenyl a-D-galactopyranoside (XXVIII). Such a mechanism may show a rate dependence on hydroxyl ion as well as on phenyl /3-D-galactopyranoside, although the reaction is so slow that the alkali dependence may not be demonstrable. 

Rate of Hydrolysis of Phenyl a-D-Galactopyranoside and of Melibiose, by Different... 

Source of enzyme Ratio of rate of hydrolysis of melibiose to that of phenyl a-D-galactopyranoside... 

Similarly, phenyl 3,4- O-isopropylidene-1 -thio-2- O-(methylthiothiocarbonyl)-(3-D-galactopyranoside and phenyl 3-O-benzyl-4,6- O-benzylidene-1 -thio-2-0-(methylthiothiocarbonyl)- 3-D-galactopyranoside gave, on brief treatment (5-10 min) with n-Bu3SnH (plus AIBN) in refluxing toluene, l,5-anhydro-2-deoxy-3,4-0-isopropylidene-D-/yxo-hex-1 -enitol (229), and l,5-anhydro-3-0-benzyl-4,6- O-benzylidene-2-deoxy-D-fyxo-hex-1 -enitol (230) in 93 and 90% yields, respectively.286... 

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