THE OPTIMIZATION OF THE ENZYMATIC-SYNTHESIS OF BETA-1,3-1,6-GLUCOOLIGOSACCHARIDES AND THEIR BIOLOGICAL-ACTIVITY

A study of the enzymic synthesis of beta-1,3; 1,6-glucooligosaccharides by means of transfer of beta-1,3-linked glucose residues from a donor, laminarine, to an acceptor, gentiotetraose, carried out by endo-beta-1,3-glucanase from sea molluscs was continued. Measuring optical rotation of the reaction mixture was selected as a convenient method for monitoring the reaction. The biological activity (simulation of soybean immunity) was found in the fractions with [alpha]D value below -40-degrees. It was shown that to increase the yield of these active substances, the reaction should be stopped at the [alpha]D value about -10-degrees. NMR spectroscopy and methylation analysis were used to corroborate the chemical structure of the biologically active substances. Both methods have shown an increase of the amount of 1 --> 3,6-glucose residues with regard to gentiooligomers.