Phenolic phenylpropanoid units

From the results presented it is evident that the 2- and 6-positions of the phenylpropanoid nuclei can be used for the modification of alkali lignin. The positions can be used for the controlled polymerization of alkali lignin. Secondly, the positions were also used to introduce hydroxymethyl groups. The hydroxymethyl groups are reactive towards nucleophiles such as phenol and resorcinol. The modification of the 2- and 6-positions of the C9 units holds tremendous potential for the utilization of alkali lignin in polymeric applications. 

The synthesis of /raw5-resveratrol oligomers requires the set of enzymes that yield trows-resveratrol from the phenylpropanoid precursor, p-coumaryl-CoA and malonyl-CoA, and then the oxidative coupling of resveratrol units by a phenol oxidase, which is presumably a class HI plant peroxidase [138,139], In fact, class HI plant peroxidases, such as that purified from grapevines, are able to oxidize frvms-resveratrol with values of 17-93 pM for H2O2 concentrations ranging from 0.1 to 5.0 mM at pH 4.0 [58], and with values of 11.9 pM" s, at the same pH [35,58]. 

Benzoic and cinnamic acid derivatives and flavonoids are the two most distributed phenolics within plants. Polyphenolic units are biosynthesized via shikimate pathway, resulting in cinnamic acids C -C phenylpropanoid building block that also contributes to other plant phenolics backbones such as those from flavonoids (Q-Ca-Ce), anthocyanidins (C6-C3-C6), and coumarins (C6-C3). Stilbeneoids (C6-C2-C6) and benzoic acid derivatives (Cfi-Ci) such as gallic and ellagic acids are also synthesized through this metabolic pathway (Fig. 1). 

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