Oxidative Properties of Lignin & Similar Compounds
You have reached the page dedicated to the research completed regarding the oxidation of lignin monomers during the summer of 2018 with the Doc Kieft Summer Research Program. This research is completed by Zelinda Taylor under the direction of Dr. Bradley Sturgeon.
Lignin Compounds
Lignin Monomers
Abstract
The synthesis of lignin via these three monomers is completed via oxidative coupling. Each monomer is composed of a phenol. P-coumaryl alcohol has no methoxy groups, coniferyl alcohol has one methoxy group, and sinapyl alcohol has two methoxy groups. These methoxy groups contribute to the overall reactivity of the compound.
Oxidation of Monomers
Beaker reactions with varying reaction conditions were completed to analyze the oxidation of each monomer. For each monomer, 100 mL of a 2 mM standard solution of the monomer was made using 50/50 dioxane/pH 5 buffer. Three reactions were then completed with varying concentrations of hydrogen peroxide in the presence of HRP. The first reaction was composed of 5 mL of the substrate, 10 microliters of hydrogen peroxide (1 mM final concentration hydrogen peroxide) and 5 microliters of HRP. The second reaction was composed of 5 mL of the substrate, 5 microliters of hydrogen peroxide (0.5 mM final concentration hydrogen peroxide) and 5 microliters of HRP. The third reaction was composed of 5 mL of the substrate, 5 microliters of hydrogen peroxide (0.25 mM final concentration hydrogen peroxide) and 5 microliters of HRP. These reactions were then analyzed on the HPLC for oxidation products of each monomer.
Analysis of Monomer Oxidation
HPLC data
Similar Compounds
Oxidation of 4-hydroxy-3-methoxybenzyl
The same beaker reactions used for the lignin monomers were completed with the 4-hydroxy-3-methoxybenzyl. A 2 mM standard was created with a volume of 100 mL using 50/50 dioxane/pH 5 buffer.