On the role of the monolignol γ-carbon functionality in lignin biopolymerization

Raman Imaging of Lignocellulosic Feedstock

“…The recalcitrance to saccharification is a major limitation for conversion of lignocellulosic biomass to ethanol, which is mainly due to the lignin [13] content and composition [14]. Lignin synthesis has extensively been investigated using lignin model compounds [15][16][17] and lignin from plants [18][19][20][21][22] and has been reviewed several times [23][24][25] including lignin structure [26] and wood formation in general [27,28]. The lignin content in natural Populus variants affects sugar release [29] and how lignin composition, structure, and cross-linking affect degradability has been reviewed for cell wall model studies [30].…”

Study of thin films of kraft lignin and two DHPs by means of single-molecule force spectroscopy (SMFS)

“…Previously, the chemical functionalities of KL and DHPs investigated here were characterized by FTIR and NMR spectroscopy (Holmgren et al 2009 ;Notley and Norgren 2010 ). For quantifying the proportion of functional groups capable of H bonding, the samples were analyzed by 31 P NMR after phosphitylation.…”

“…lacks signifi cant amounts of OH groups on the α -carbon, whereas they are abundant in DHP c.alc. (Holmgren et al 2009 ). This is supported by the 31 P NMR data ( Table 1).…”

“…and coniferyl alcohol (leading to DHP c.alc. ) according to Holmgren et al (2009) . One gram of monolignols was dissolved in 10-ml acetone and then mixed with horseradish peroxidase type VI (5 mg, 1450 U) and 190 ml of 50 mM K 2 HPO 4 buffer (pH 6.5) ( " bulk polymerization " mode).…”

“…was about 4500 Da (Mw/Mn 1.4) and that of DHP c.ald. about 2700 Da (Mw/Mn 1.4) (data obtained by using size exclusion chromatography according to Holmgren et al 2009 , who also provided the 13 C NMR data of these samples).…”