Influence of saccharides production

The symbols Gn , Gm , and Gx represent straight-chain malto-oligosaccharides containing n, m, and x units of (I ->4)-Cl.-D-glucopyranose; cGx is a CD composed of x units. A D-glucose unit at the non-reducing end of a (I ->4)-X-D-glucopyranosyl chain appears to be transferred by way of either 0-4 or C-4 to either C-I or 0-1 of another D-glucose unit that functions as a suitable donor. A variety of sugars and sugar derivatives were examined for the effect of their presence on conversion of maltodextrin (average degree of polymerization 22) into cyclomalto-oligosaccharides (cyclodextrins; CDs) by cyclodextrin glucanotransferase. Those saccharides having structural features known to be necessary for high efficiency as acceptors in intermolecular transglycosylation behaved as strong inhibitors of cyclization. Their presence resulted in lower-than-normai yields of CDs. The basic requirement for strong inhibition by a simple sugar is a 0or L-g!ucopyranose structure with unsubstituted hydroxy groups at C-2, C-3. and C-4. Replacement of a hydroxy group at C-I or C-6 with other substituents mayor may not eliminate inhibitory abilit'f, depending upon the nature of the substituent. Replacement of the hydroxymethyl group at C-S with a hydrogen atom results in strong inhibition only when the sugar is in the L form.