Chemical and in vivo evaluation of a brown midrib mutant of zea mays. II. Nuclear magnetic resonance spectra of digested and undigested alkali lignins and undigested dimethyformamide lignins

Publisher Website
Google Scholar
Abstract
Nuclear magnetic resonance (n.m.r.) spectra were obtained on the alkali lignins extracted from Tr and bm1 cornstalks, before and after digestion by sheep, and on the dimethylformamide lignins (DMFL) from undigested cornstalks. Differences due to solvent extraction, plant genotype and digestion were apparent. The bm1 corn lignin has a higher degree of cross linking of the propane side chain of the lignin molecule than Tr corn lignin, a factor which may be significant in determining the effect of lignin on digestibility. The main effect of digestion was to increase the degree of cross‐linking of the propane side chain, especially with the Tr lignin. Alkali lignin n.m.r. spectra were considerably different from DMFL n.m.r. spectra. For example over 40% of the total bm DMFL protons were highly shielded protons but these were virtually absent in the alkali lignins. These highly shielded protons cannot be explained by the presence of ferulic and p‐coumaric acids in DMFL.