THE STRUCTURES OF PHOSPHORYL OLIGOSACCHARIDES PREPARED FROM POTATO STARCH

In the previous study, we proposed that phosphoryl oligosaccharides (P Os) prepared from potato starch had an inhibitory effect on the format ion of a calcium phosphate precipitate in vitro. In this study, we inv estigated the structures of the phosphoryl oligosaccharide-1 (PO-1) fr action that was the main component of POs, By treating with bacterial saccharifying alpha-amylase (BSA) after glucoamylase (GA), the PO-1 fr action produced 3(2)-phosphoryl maltotriose from 3-phosphoryl oligosac charides, and 6(3)-phosphoryl maltotriose from 6-phosphoryl oligosacch arides. These products were characterized spectrometrically as well as chemically, including measurement of the amounts of the non-reducing- terminal residue, reducing-terminal residue, and organic phosphate, A small amount of 6(2)-phosphoryl maltose was also detected after treati ng with GA alone, indicating that 6(2)-phosphoryl maltotriose existed in the PO-1 fraction, According to the reaction specificities of GA an d BSA, we conclude that the PO-1 fraction was made up of 3-phosphoryl oligosaccharides (3(3)-phosphoryl maltotetraose and 3(4)-phosphoryl ma ltopentaose) and 6-phosphoryl oligosaccharides (6(3)-phosphoryl maltot riose, 6(2)-phosphoryl maltotriose, 6(3)-phosphoryl maltotetraose, and 6(4)-phosphoryl maltopentaose).