Localization of acetyl groups in macromolecules of glucomannan from Eremurus zangezuricus roots

Water-soluble glucomannan from roots of Eremurus zangezuricus Mikheev was studied. The polysaccharide contains D-glucose, D-mannose, and acetyl groups in the molecular ratio of 1:2.8:0.38. 13C NMR studies showed that the polysaccharide under study is a linear, partly acetylated 1,4-beta-D-glucomannan. The acetyl groups are attached to the C2 and C3 of mannopyranose units. The polymer contains, on average, one acetyl group per seven mannose units. The glucomannan of E. zangezuricus has the following parameters: alpha]D = -37.5 degrees, eta] = 3.73 dl/g, and Mw = 151 kDa.