How to Get More Out of Wood Waste - Breaking Down Lignin to Get Useful Aromatic Compounds

Lignin makes up almost a third of our planet's organic carbon and is a large waste component in paper processing. Research efforts have been focused on breaking this difficult material down and use its components for other useful purposes. The research team of Alireza Rahimi, Arne Ulbrich, Joshua J. Coon, and Shannon Stahl at UW-Madison have figured out a way to break down lignin.

  Lignin and cellulose are responsible for the structural strength of plant cell walls (left image)

A lot of lignin is produced from paper processing (right image)

How does this relate to what we’ve learned in general chemistry?

Lignin makes up almost a third of our planet’s organic carbon and is a large waste component in paper processing. Research efforts have been focused on breaking this difficult material down and use its components for other useful purposes. The research team of Alireza Rahimi, Arne Ulbrich, Joshua J. Coon & Shannon S. Stahl at UW-Madison have figured out a way to break down lignin. One of the first steps is the chemical oxidation of a secondary alcohol group into a ketone, which is a key step in being able to break it down into smaller and potentially useful aromatic molecules.

Lignin (from popular or aspen) 

Article: 

Formic-acid-induced depolymerization of oxidized lignin to aromatics; Alireza Rahimi, Arne Ulbrich, Joshua J. Coon & Shannon S. Stahl (researchers at UW-Madison Depts. Of Chemistry and Biochemistry); Nature 515, 249–252 (13 November 2014) doi:10.1038/nature13867

Amino Acid in Watermelon Juice Relieves Muscle Soreness : L-Citrulline

                 

Most amino acids have a chiral center with carboxylic acid and amine functional groups. 

(http://en.wikipedia.org/wiki/Amino_acid)

Researchers M. P. Tarazona-Diaz, F. Alacid, M. Carrasco, I. Martinez, and E. Aguayo tested the efficacy of L-citrulline on muscle soreness vs. a placebo. For a small group of young male volunteers in an ergometer exercise test, there was determined to be no significant difference in blood lactate concentration during the activity. But after 24 hours, recovery from delayed onset muscle soreness improved subsequent to ingesting 500. mL of natural and enriched watermelon juice. 

Watermelon contains an amino acid known as L-citrulline which is also known to be an intermediate in the urea cycle, a biochemical pathway in the liver that enables the body to convert ammonia waste into urea which eventually is eliminated via the kidneys.

 

L-citrulline         

The name comes from citrullus, meaning "watermelon". (http://en.wikipedia.org/wiki/Citrulline)

 

http://en.wikipedia.ord/wiki/Urea_cycle