The location of the O-acetyl groups in the (1→3)-α-d-mannan from Dictyophora indusiata fisch

✍ Scribed by Chihiro Hara; Tadashi Kiho; Shigeo Ukai

• Book ID: 102990998
• Publisher: Elsevier Science
• Year: 1982
• Tongue: English
• Weight: 542 KB
• Volume: 111
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(82)85014-3

✦ Synopsis

A linear (l-3)-a-D-mannan (T-2-HN) isolated from the hot, 70 % aqueous ethanol extract of the fruit bodies of Dictyophora indusiutu Fisch. contained about one 0-acetyl group per two D-mannosyl residues in the molecule. The locations of the 0-acetyl groups were elucidated by the methyl-replacement method involving the use of (1-methoxyethyl) protecting groups. The results indicated that most of the acetyl groups (-88 'A) are located solely at O-6 of the cr-(1+3)-linked D-mannopyranosyl residues in T-2-HN. In addition, small proportions of acetyl group are located on O-2,6, O-4,6,0-2, and O-4 of the D-mannosyl residues, and this conclusion was well supported by the results of a 13C-n.m.r.-spectral study. The molecular weights (Mw) of T-ZHN and its deacetylated product (water-insoluble) were, by gel chromatography on Sepharose CL-2B with 0.1~ sodium chloride and 2~ sodium hydroxide as the eluants, respectively determined to be 620,000 and 550,000.