Active CRIS Projects:

3655-21000-033-03T John Ralph

ELUCIDATION OF THE PATHWAY FOR NATURAL LIGNIN ACYLATION

Objectives: To improve our understanding of aspects of lignification & lignin acylation to provide a basis for enhancing utilization of plant resources in various natural & industrial processes. This work will elucidate the actual pathway(s) of lignin acylation, & seek proof that acylation is at the monolignol stage, allowing one to seek the substrates & transferases involved in acylation of monolignols, & to identify the genes responsible. Up& down-regulation in crop plants will be assessed.

Approach: The key is to find lignification pathways that are diagnostically altered if monolignols are pre-acylated, & to elucidate the chemistry involved in such pathways, using the following steps: 1. Determine if lignins are gamma-acylated by p-hydroxybenzoates; are p-hydroxybenzoates analogous to lignin esters? The regiochemistry of attachment will be via our DFRC analytical method and NMR. 2. Fully elucidate (by biomimetic coupling reactions, and NMR and MS analysis) the nature of beta-beta-coupling products from acylated monolignols to understand the expected products that will arise in lignin if these acylated monomers are incorporated. 3. Determine & characterize the DFRC products from acylated beta-betadimers and their ethers by NMR and MS. 4. Search for these acylated beta-beta-products in natural lignins by sensitive GC-MS methods and NMR, following DFRC degradation. This will be done for a variety of plants that have acylated lignins.