AN IMPROVED METHYLATION PROCEDURE FOR THE ANALYSIS OF COMPLEX POLYSACCHARIDES INCLUDING RESISTANT STARCH AND A CRITIQUE OF THE FACTORS WHICH LEAD TO UNDERMETHYLATION
Pw. Needs et Rr. Selvendran, AN IMPROVED METHYLATION PROCEDURE FOR THE ANALYSIS OF COMPLEX POLYSACCHARIDES INCLUDING RESISTANT STARCH AND A CRITIQUE OF THE FACTORS WHICH LEAD TO UNDERMETHYLATION, Phytochemical analysis, 4(5), 1993, pp. 210-216
Deficiencies in the widely used Hakomori method of methylation are des
cribed. Evidence is given that this method of linkage analysis often g
ives levels of undermethylation which hamper the detailed study of com
plex carbohydrates from plant cell walls. A modified method using sodi
um hydroxide as base is described which is capable of fully methylatin
g polymers for which the Hakomori method generally fails and which doe
s not promote the carbohydrate oxidation typical of a former procedure
using this reagent. An explanation of its efficacy is advanced. Analy
ses of retrograded, alpha-amylase-resistant starches obtained by the m
odified method are reported.