Synthesis and identification of 2,5-bis-(4-hydroxy-3-methoxyphenyl)-tetrahydrofuran-3,4-dicarboxylic acid, an unanticipated ferulate 8-8-coupling product acylating cereal plant cell walls.
A new product implicated in cereal grain polysaccharide cross-linking has been authenticated by independent synthesis. Saponification of cereal grain fiber releases the RRRS/SSSR-isomer of 2,5-bis-(4-hydroxy-3-methoxyphenyl)-tetrahydrofuran-3,4-dicarboxylic acid. The parent ester logically derives from 8-8-coupling of ferulate followed by water addition to one of the incipient quinone methide moieties and internal trapping of the other. The finding adds complexity to the analysis of plant cell wall cross-linking, but provides clues to important polysaccharide cross-linking pathways occurring in planta.
Schatz
Paul F
PF
US Dairy Forage Research Center, USDA-Agricultural Research Service, 1925 Linden Drive West, Madison, WI 53706, USA. schatz@chem.wisc.edu
Ralph
John
J
Lu
Fachuang
F
Guzei
Ilia A
IA
Bunzel
Mirko
M
D000215:Acylation; D002264:Carboxylic Acids / Q000138:chemical synthesis* / Q000737:chemistry*; D002473:Cell Wall / Q000737:chemistry*; D003373:Coumaric Acids / Q000737:chemistry*; D018360:Crystallography, X-Ray; D002523:Edible Grain / Q000737:chemistry*; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism
C513521:2,5-bis-(4-hydroxy-3-methoxyphenyl)-tetrahydrofuran-3,4-dicarboxylic acid; D002264:Carboxylic Acids; D003373:Coumaric Acids; D005663:Furans; C004999:ferulic acid