NMR evidence for benzodioxane structures resulting from incorporation of 5-hydroxyconiferyl alcohol into lignins of O-methyltransferase-deficient poplars

Benzodioxane structures are produced in lignins of transgenic poplar plants deficient in COMT, an O-methyltransferase required to produce lignin syringyl units. They result from incorporation of 5-hydroxyconiferyl alcohol into the monomer supply and confirm that phenols other than the three traditional monolignols can be integrated into plant lignins.