PAL is the first enzyme in phenylpropane
Cellulose and hemicelluloses are polysaccharides, while lignin is an amorphous polyphenolic macromolecule consisting of three types of phenylpropane
units, forming a complex, highly branched and amorphous structure.
Lignin is an amorphous polymer consisting of phenylpropane
units) are not linked to each other in any systematic order.
It is a complex polymer consisting of cross linked phenylpropane
units which contains large numbers of various types of ether linkages and free phenol groups.
Using animal models, bioassay-guided fractionation of various extracts of plant adaptogens have shown that the active principles are mainly phenylpropane
and phenylethane derivatives including salidroside, rosavin, syringin, triandrin, tyrosol, etc.
Hydroxybenzyl alcohol groups as well as sulfonic acid groups on the carbon alpha to the aromatic rings of the phenylpropane
units of the random polymer react with the aromatic nuclei of other phenylpropane
units in the presence of the strong mineral acids.
The structure of lignin varies, but all lignins are comprised of a three-dimensional network of phenylpropane
The third polymeric component is lignin that is made up of variously modified phenylpropane
moieties linked by numerous types of linkages including carbon-carbon bonds and aryl-alkyl ether linkages.
Its basic structural unit consists of phenylpropane
with a phenol ring that is substituted by zero, one, or two methoxyl groups.
In addition to normal H, G, and S units, lignins can contain high levels of unusual phenylpropane
units, particularly if enzymes in the lignin pathway are perturbed by mutations or genetic engineering (Boerjan et al.
We found that several of these BPA analogues, including BPB, 2-(4'-hydroxyphenyl)-2- phenylpropane
(HPP), and bisphenol AF (BPAF), could activate hPXR in a dose- dependent manner (Figure 4B).