Structure of the Degraded Anacardium occidentale (Cashew Nut Tree) Gum

Department of Sugar Chemistry, National Sugar Institute, Kanpur-208 017 Manuscript received 10 April 1978, revised 3 June 1980, accepted 26 July 1980 The structure of the degraded \(Anacardium\) \(occidentale\) gum has been deduced from the results of methylation, periodate oxidation and Smith degradation experiments Completely methylated degraded gum upon acid hydrolysis produced 2,3,4,6-tetra-, 2,4,6-tri-, 2,3,4,-tri- and 2,4-di-O-methyl-D-galactose and 2,3,4-tri-\(O\)-methyl-D-galac­turonic acid in a molar ratio of 1:2:2:2:1. This shows the branched chain nature of the degraded gum and its repeating unit consists of a 1→3 linked galactan main chain to which are attached two side chains of galactose and aldobiouronic acid by 1→6 linkages. The results of periodate oxidation and Smith degradation confirm the above structure. The molecular weight determination shows that the repeating unit is repeated seventeen times in the full structure of the degraded A. \(occidetitale \) gum