Lignin in grass

Advantages of the DFRC method over thioacidolysis include the better yield, simpler and milder reaction conditions, and the fact that esters are not cleaved. Especially in the analysis of lignin in grasses, with large amounts of esterified / -coumaric acid (1.13), this is an important consideration. 

Nitrobenzene and Cupric Oxide Oxidations of Lignins in Grass Tissues... 

Hatfield, R. D. Ralph, J. Grabber, J. H. A potential role of sinapyl p-coumarate as a radical transfer mechanism in grass lignin formation. Planta 2008, 228, 919-928. 

It is unclear how accurate this method is for the determination of lignin content in grasses, since a fraction of the lignin from grasses appears to be readily soluble in acidic solutions, such as used in this procedure. This would result in underestimation of the actual lignin content (Hatfield and Fukushima, 2005). 

Hodson, R.E, Christian, R.R., and Maccubbin, A.E. (1983) Lignocellulose and lignin in the salt marsh grass Spartina altemiflora initial concentration and short-term, post-depositional changes in detrital matter. Mar. Biol. 81, 1-7. 

Determination of p-Hydroxycinnamic and Ferulic Acid Ester Units in Grass Lignins... 

Lam, T.B.T. Kadoya, K. Liyama, K. 2001. Bonding of hydroxycinnamic acids to lignin ferulic and />-coumaric acids are predominantly linked at the benzyl position of lignin, not tbe beta-position, in grass cell walls. Ph54ochem. 57 987-992. 

Ferulates in Lignins Cell Wall Cross-Linking in Grasses by Ferulates.190... 

An extension of the DHP methods is to prepare lignins within preformed cell walls [203,204]. The walls may have their own peroxidases and other features, such as ferulates that may act as lignin nucleation sites in grass walls [130]. The... 

S units by quantitative NMR spectroscopy (Quantitative C NMR of Lignins section) or from 2D HSQC spectra (Quantification in 2D NMR section). Other differences between GS lignins are frequently the presence of unique entities, such as incorporated hydroxycinnamates (Ferulates in Lignins Cell Wall Cross-Linking in Grasses by Ferulates section), and y-acylated units (p-Hydroxybenzoates in Various Flardwoods section) [309]. 

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