真菌の生化学的免疫化学的研究(第12報) : Aspergillus fumigatus培養濾液および菌体Galactomannanについて

抄録

Two galactomannans have been isolated from culture filtrate and dried cells of Aspergillus fumigatus by Sephadex G-50, DEAE- and CM-cellulose column chromatography. The cell-galactomannan ([α]²⁰_D -17.5, 2.1S) was determined to be homogeneous by the ultracentrifugal and electrophoretic analysis. The culture filtrate-galactomannan ([α]²⁰_D -2, 1.8S) was also homogeneous. Sugar components of galactomannans are composed of galactose and mannose in molar ratio of 1 : 1. On the partial hydrolysis, cell-galactomannan and culture filtrate-galactomannan removed 40% galactose and 9% oligosaccharide (Gal : Man=4 : 5), leaving 51% mannan fraction ([α]²⁰_D +38.8, 1.7S) composed of galactose and mannose in a molar ratio of 2 : 15. From the results of periodate oxidation of cell-galactomannan, culture filtrate-galactomannan and the mannan fraction, it was found that periodates consumed were 0.90 mole, 0.84 mole and 0.80 mole, released formic acid were 0.8 mole, 0.8 mole and 0.6 mole per anhydrohexose unit, respectively. Sugar components of periodate-oxidized galactomannan were confirmed to be mannose, glycerol and small amounts of galactose. Presumable structure of the galactomannan was attached galactofuranose residue and oligosaccharide (Gal : Man=4 : 5) as side chain to mannan core consisted of α_1→2, α_1→3, α_1→6 D-mannopyranose unit. It was shown that cell-galactomannan and culture filtrate-galactomannan were similar in chemical and physical properties.