THE SUBSTRATE-SPECIFICITY OF THE ENZYME AMYLOGLUCOSIDASE (AMG) .2. 6-SUBSTITUTED MALTOSE DERIVATIVES

The synthesis of maltose derivatives substituted in the 6-position with F, I, N3, NH2, NHAc, COOH or COOMe, and having a 5-6 double bond, are described together with the preparation of the known 6-Cl and 6-Br derivatives using improved synthetic procedures. Furthermore, the 6''-Br and -F derivatives have been prepared. The identities of the deprotected methyl glycosides have in all cases beeen established by 1H and 13C NMR spectroscopy. The synthetic compounds have been tested as substrates for the enzyme amyloglucosidase (AMG) and it has been found that compounds with a charged group in the 6-position, such as amino or carboxylase, or with substituents in the 6''-position are not substrates for the enzyme; all the other compounds can be hydrolysed by the enzyme, although at widely differing rates. The 6-halo compounds proved in competition experiments to be potent enzyme inhibition.