Skip to main content
ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Research » Publications at this Location » Publication #66545
Title: PREPARATION OF SYNTHETIC LIGNINS WITH SUPERIOR NMR CHARACTERISTICS

Author
item Ralph, John
item ZHANG, YINGSHENG - UNIV OF WISCONSIN-MADISON
item EDE, RICHARD - UNIV OF WAIKATO, NZ

Submitted to: American Chemical Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 3/28/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Synthetic lignins (DHP's) are valuable for studying aspects of lignification, cross-linking, and lignin structure. If they are not too highly polymeric, they are soluble in normal lignin solvents and amenable to solution-state NMR studies. However, in the application of inverse- detected correlation experiments, particularly the popular HMQC and HMBC, the spectra have annoying T1-noise ridges that can be quite overwhelming. These artifacts make it difficult to locate correlation peaks that are near the methoxyl in the proton dimension. One solution to this is to use gradient-enhanced NMR but that requires additional hardware that is not yet commonplace. An alternative is to produce coniferyl alcohol in which the atoms of the methoxyl group are NMR-invisible. We have accomplished this simply by preparing lignin monomers (coniferyl and sinapyl alcohols) using 13C-depleted deuterated methyl iodide (12CD3I). The method is simple enough hand cheap enough that these monomers can be utilized for any DHP's destine for NMR studies. The NMR spectra of DHP's derived from these 'methoxyl- less' monomers are spectacularly superior to their normal-monomer counterparts.