title: Isolation of structurally distinct lignin-carbohydrate fractions from maize stem by sequential alkaline extractions and endoglucanase treatment.
abstract: Sequential fractionation of extractive-free maize stems was carried out using two mild alkaline extractions (0.5 and 2 M NaOH, 20°C, 24h) before and after endoglucanase treatment. This procedure provided two lignin-carbohydrate fractions (LC1 and LC2) recovered after each alkali treatment. LC1 and LC2 contained 39% and 8% of the total lignin amount, respectively. These two fractions contained structurally distinct lignin molecules. While the content of resistant interunit bonds in lignin was 77% in LC1, it was increased up to 98% in LC2. Not unexpectedly, both alkali-soluble fractions contained substantial amount of p-coumaric and ferulic acids ether-linked to lignins. These results outline heterogeneity of maize stem lignins related to fractionation of grass materials.
authors: Aalto University, School of Chemical Technology, Department of Biotechnology and Chemical Technology, Espoo, Finland. mika.sipponen@aalto.fi
authors: Mika Henrikki
authors: MH
authors: Sipponen
authors: Catherine
authors: C
authors: Lapierre
authors: Valérie
authors: V
authors: Méchin
authors: Stéphanie
authors: S
authors: Baumberger
mesh_terms: D000468:Alkalies / Q000737:chemistry*; D002241:Carbohydrates / Q000737:chemistry / Q000302:isolation & purification*; D002480:Cellulase / Q000378:metabolism*; D005591:Chemical Fractionation / Q000379:methods*; D003373:Coumaric Acids / Q000302:isolation & purification; D008031:Lignin / Q000737:chemistry / Q000302:isolation & purification*; D009005:Monosaccharides / Q000032:analysis; D018547:Plant Stems / Q000737:chemistry*; D011422:Propionates; D017550:Spectroscopy, Fourier Transform Infrared; D003313:Zea mays / Q000737:chemistry*
chemical_list: D000468:Alkalies; D002241:Carbohydrates; D003373:Coumaric Acids; D009005:Monosaccharides; D011422:Propionates; C036909:lignocellulose; D008031:Lignin; C004999:ferulic acid; D002480:Cellulase; C495469:p-coumaric acid