Enzymically produced cyclic alpha-1,3-linked and alpha-1,6-linked oligosaccharides of D-glucose.

A new type of bacterial enzyme hydrolyzed alternan (Leuconostoc mesenteroides NRRL B-1355 fraction S dextran, an alternating alpha-1,3-alpha-1,6-D-glucan) to give rise to a series of oligosaccharides. The oligosaccharide formed in the greatest proportion was a cyclic tetrasaccharide of D-glucosyl residues linked in an alternating alpha-1,3-alpha-1,6 fashion. Other saccharide products included isomaltose and alpha-D-glucopyranosyl-1,3-alpha-D-glucopyranosyl-1,6-D-glucose. Oligosaccharides of higher degrees of polymerization were also formed, and included alpha-D-glucosylated derivatives of the cyclic tetrasaccharide. This is the first report of a naturally produced cyclic tetrasaccharide.