SYNTHESIS OF DEOXY DERIVATIVES OF LACTOSE AND THEIR HYDROLYSIS BY BETA-GALACTOSIDASE FROM ESCHERICHIA-COLI

Methyl 2-deoxy-alpha-lactoside, methyl 3-deoxy-beta-lactoside, 1,5-anhydro-4-O-beta-D-galactopyranosyl-D-glucitol and the 2-deoxy and 2,3-dideoxy derivatives of 1,5-anhydro-4-O-beta-D-galactopyranosyl-D-glucitol have been synthesized by deoxygenation of lactose derivatives at appropriate positions. Cyclohexyl beta-D-galactopyranoside has also been synthesized. All derivatives proved to be substrates for the enzyme beta-galactosidase from E. coli, but the rate of hydrolysis of the substrate analogues was strongly dependent on the nature of the aglycone.