ENZYMATIC-SYNTHESIS OF POLYOL-GLYCOSIDES AND MASKED POLYOL-GLYCOSIDESUSING BETA-GLYCOSIDASE OF SULFOLOBUS-SOLFATARICUS

The use of commercially available mesophilic glycosidases in the enzym atic synthesis of glycosides of different types is a well established method suffering from some drawbacks such as a poor yield. Substrates with three or four hydroxyl groups have been subjected to enzymatic gl ucosylation using crude homogenate of the thermophilic archaeon Sulfol obus solfataricus containing a beta-glycosidase activity able to trans fer glucose, galactose and fucose from different donors. The stereoche mistry of this reaction was interpreted in terms of interaction with a possible ''glucose'' active site of the enzyme. In addition masked or protected derivatives of tetritols and some simple unsaturated alcoho ls were glycosylated yielding glycosides in yields very competitive wi th those obtained using mesophilic enzymes, examples of further chemic al manipulation of these compounds were reported. When using a scarce amount of acceptor, a reasonable amount of products could be obtained by adding different aliquots of donor at time intervals.