Macromolecular lignin

Biogenesis and Structure of Macromolecular Lignin in the Cell Wall of Tree Xylem as Studied by Microautoradiography... 

Guan, S. Y., Mylnar, J., and Sarkanen, S., 1997, Dehydrogenative polymerization of coniferyl alcohol on macromolecular lignin templates,... 

Macromolecular lignin product, vanillic, fenilic, coumaric and other acids - Microbial conversion... 

Unlike other forms of chromatography that are driven by enthalpy terms in thermodynamic equilibrium, SEC is an entropy-controUed chromatographic separation technique that is, under ideal conditions, based solely on solute size. Although SEC is a relatively rapid and simple method for determining the MWDs and average molecular weights of macromolecular lignins, there are some strict requirements that must be met for proper use of this technique. 

Davin LB, Jourdes M, Patten AM et al (2008) Dissection of lignin macromolecular configuration and assembly comparison to related biochemical processes in allyl/propenyl phenol and hgnan biosynthesis. Nat Prod Rep 25 1015-1090... 

Many, but not all, macromolecules are created by the mutual chemical chain reactions of small molecules called monomers and the arising species contain repeated small units, mers. In that case they are designated oligomers or polymers depending on their molar mass. This means that all oligomers and polymers can be called macromolecular substances but not all macromolecular substances are of oligomeric or polymeric nature (lignin, humin substances, etc.). Properties of macromolecular systems depend on... 

The understanding of the macromolecular properties of lignins requires information on number- and weight-average molecular weights (Mn, Mw) and their distributions (MWD). These physico-chemical parameters are very useful in the study of the hydrodynamic behavior of macromolecules in solution, as well as of their conformation and size (1). They also help in the determination of some important structural properties such as functionality, average number of multifunctional monomer units per molecule (2, 3), branching coefficients and crosslink density (4,5). 

In addition to water and inorganic solids (salts dissolved in cell fluids, shells, and bones), organisms consist of a mix of organic substances. Some of these are macromolecules (e.g., globular proteins, cellulose). Some combine to form subcellular and tissue structures built with combinations of lipids, proteins, carbohydrates, and some specialized polymers like cutin or lignin (Fig. 10.2). These diverse organic materials cause organisms to have diverse macromolecular, cellular, and tissue portions that may be apolar, monopolar, and/or bipolar. 

Lignins are a group of macromolecular heteropolymers (600-1000 kDa) found in the cell wall of vascular plants that are made up of phenylpropanoid units. Lignin has proven to be a useful chemical biomarker for vascular-plant inputs to estuarine/coastal margin sediments. Cellulose, hemicellulose, and lignin generally make up > 75% of the biomass of woody plant materials. 

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