%A Ragauskas,Arthur
%A Pu,Yunqiao
%A Samuel,Reichel
%A Jiang,Nan
%A Fu,Chunxiang
%A Wang,Zeng-Yu
%D 2014
%J Frontiers in Energy Research
%C
%F
%G English
%K Switchgrass,COMT transgenic,Lignin,NMR,GPC,Molecular Weight
%Q
%R 10.3389/fenrg.2013.00014
%W
%L
%M
%P
%7
%8 2014-January-20
%9 Original Research
%+ Prof Arthur Ragauskas,Georgia Institute of Technology,School of Chemistry and Biochemistry,500 10th St., NW,Atlanta,30332,GA,United States,aragausk@utk.edu
%#
%! Lignin in COMT Down-regulated Switchgrass
%*
%<
%T Structural Characterization of Lignin in Wild-Type versus COMT Down-Regulated Switchgrass
%U https://www.frontiersin.org/articles/10.3389/fenrg.2013.00014
%V 1
%0 JOURNAL ARTICLE
%@ 2296-598X
%X This study examined the chemical structural characteristics of cellulolytic enzyme lignin isolated from switchgrass focusing on comparisons between wild-type control and caffeic acid 3-O-methyltransferase (COMT) down-regulated transgenic line. Nuclear magnetic resonance techniques including 13C, 31P, and two-dimensional 13C-1H heteronuclear single quantum coherence as well as gel permeation chromatography were employed. Compared to the wild-type, the COMT down-regulated transgenic switchgrass lignin demonstrated a decrease in syringyl (S):guaiacyl (G) ratio and p-coumarate:ferulate ratio, an increase in relative abundance of phenylcoumaran unit, and a comparable content of total free phenolic OH groups along with formation of benzodioxane unit. In addition, COMT down-regulation had no significant effects on the lignin molecular weights during its biosynthesis process.