Lignin structure heterogeneity

For the further study of the structural heterogeneity of lignin, mild and selective cleavage of bonds, pyrolysis gas chromatography-mass spectrometry (GC-MS), and solid state nuclear magnetic resonance are particularly important. 

BAU 98] Baumberger S., Lapierre C., Monties B., Utilization of pine kraft lignin in starch composites impact of structural heterogeneity . Journal of Agricultural and Food Chemistry, vol. 46, no. 6, pp. 2234-2240,1998. 

Plant cell walls are complex, heterogeneous structures composed mainly of polymers, such as cellulose, hemicelluloses, and lignins. In spite of several decades of research, cell wall assembly and the biosynthesis and ultimate biodegradative pathways of individual polymers are still far from being fully understood. One simple example will suffice Even today, no enzyme capable of catalyzing cellulose formation in vitro has been obtained. 

There are different types of photochromic systems (5), e.g. triplet-triplet absorption, cis-trans isomerization or homolytic dissociation reactions. Since lignin has a very heterogenous and complex structure there is probably not a single responsible system, but rather a mixture of systems. 

Terashima N, Tomimura Y, Araki H (1979) Heterogeneity in formation of lignin III Formation of condensed type structure with bond at position 5 of guaiacyl nucleus Mokuzai Gakkaishi 25 595-599... 

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