Author
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LU, FACHUANG - UNIV OF WISCONSIN-MADISON |
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Ralph, John |
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Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 6/16/1998 Publication Date: N/A Citation: N/A Interpretive Summary: Lignin, the second most abundant land-based natural polymer, occurs in all land plants. In the plant, the polymer is built from small natural compounds, coniferyl and sinapyl alcohols. In grasses, some of these components are attached to another compound, p-coumaric acid as an "ester." This gives grass lignins significantly different properties to those in other plants, legumes and woody plants. We and other researchers have a need for the esters for a variety of plant studies ultimately relating to the digestibility of plants to ruminant animals. The compounds have been made previously, including by our own group, but the syntheses were troublesome and the required products were difficult to purify. The new synthetic methods described here produce the required lignin esters cleanly and simply, making them more readily available to researchers. The compounds are used in studies that are at the heart of efforts to improve agricultural sustainability and maximize our plant resources. Technical Abstract: Coniferyl p-coumarate (4-hydroxy-3-methoxycinnamyl 4-hydroxycinnamate) and sinapyl p-coumarate (3,5-dimethoxy-4-hydroxycinnamyl 4-hydroxycinnamate) were synthesized in high overall yield. In this improved method, acetate was used as the phenol protecting group instead of 2,4-dinitrophenyl ether; selective deacetylation, without cinnamate ester hydrolysis was accomplished with neat pyrrolidine. |
