細菌に依る澱粉の一結晶性分解成績体に就いて (第5報)

新六糖体の構造

抄録

Chemical structure of the methylated compound of the new hexasaccharide (new crystalline dextrin) was examined and it was found to be a oligosaccharide in which 6mol. of 2, 3, 6-trimethylglucopyranose were bonded in a ring form, similar to the previously reported hexasaccharide.
Treatment of the completely methylated compound of the new saccharide with conc. HCl at a low temperature gives trimethylglucose, which can be assumed to be its structural components, in a 93% yield. This compound gives an m.p. of 114°, [α]_D=+90°. Its chemical examination revealed that it posseses an oxygen bridge between C₁ and C₅, and a free OH radical at C₄, so that the structure was proved to be 2, 3, 6-trimethyl-glucopyranose.
Changes in the α_D value of the saccharide was examined by its hydrolysis with 50% H₂SO₄ at a room temperature and a temporary increase in α_D value was observed which is the specific characteristics of cyclic polysaccharides as stated by Freudenberg. From these facts, the new compound was assumed to be a cyclic hexasaccharide.