Related Experiment Video
Updated: Nov 17, 2025

Extraction of Lignin with High β-O-4 Content by Mild Ethanol Extraction and Its Effect on the Depolymerization Yield
Published on: January 7, 2019
Protocatechuic acid production from lignin-associated phenolics
1Institute of Chemical Technology, DBT-ICT Centre for Energy Biosciences, Mumbai, India.
Abstract:
Biobased chemicals are gaining popularity and market in attempts to mitigate the deteriorating environmental and sustainability issues. Components of renewable agricultural and forest biomass residues are projected to serve as abundant precursors to synthesis of expanding range of products. Agroindustrial wastes comprises of several phenolic compounds associated with lignin via ether linkages such as ferulic acid, p-coumaric, syringic acid and vanillin. These aromatic chemicals have myriad industrial applications. In this study, p-coumaric acid and ferulic acid were found to be two major components in corn bran derived lignin hydrolysate. Engineered Pseudomonas putida KT2440 was constructed and found to convert p-coumaric acid and vanillic acid to protocatechuic acid in >90% and >50% yields, respectively. Engineering the strain included deletion of the gene encoding protocatechuate 3,4-dioxygenase, and overexpression of vanillate-O-demethylase gene from Acinetobacter sp. ADP1.
Related Concept Videos
Vicinal Diols via Reductive Coupling of Aldehydes or Ketones: Pinacol Coupling Overview
Loss of Carboxy Group as CO2: Decarboxylation of Malonic Acid Derivatives
Products of the Citric Acid Cycle
Preparation of Diols and Pinacol Rearrangement
The reaction begins with transferring a proton from the acid catalyst to one of the hydroxyl groups, producing an oxonium ion.
Oxidation of Phenols to Quinones
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox...

