Abstract
1. In continuation of the foregoing work, the group mucopolysaccharide, prepared by alkaline scission of pig stomach mucus at room temperature, (MP I) was investigated with respect to the union between its polypeptide and carbohydrate moieties.
2. A partial degradation product of MP I, which was still group active, (MP II) was obtained in crystalline form. It contains three molecules of acetylglucosamine, two molecules of acetylgalactosamine, five molecules of galactose and one molecule each of L-fucose, serine and alanine per unit molecule and is devoid of sialic acid. Moreover, it lacks acetal link.
3. As products by alkaline hydrolysis of MP II, a tetrasaccharide composed of one molecule of acetylglucosamine, two molecules of galactose and one molecule of L-fucose (“gastro-N-tetrasaccharide”) and two undialyzable high-molecular polypeptide-polysaccharide complexes were separated. In gastro-N-tetrasaccharide, one of the galactose molecules stands at the reducing terminal and the L-fucose molecule is bound in a manner stable against acetic acid. One of the polypeptide-polysac-charide complexes is most probably a fragment whose multiple makes up MP II deprived of the tetrasaccharide.
4. Ester linkage between the carboxyl of alanine and a hydroxyl in gastro-N-tetrasaccharide was suggested.
5. Crystalline N-acetylglucosamine-galactoside serine ether was isolated from a H2SO4-hydrolysate of MP II.
6. From the findings above and those in other articles from this laboratory a partial structure of MP I and II are discussed.
Through the Grant Committee for Scientific Researches the Ministry of Education gave a grant in aid to us, which is gratefully acknowledged. H. Masamune.
