Understanding of Natural Aromatic Polymer via Biosynthesizing Dehydrogenation Polymer (DHP)

Authors: Yanying Cao, Chang Geun Yoo

SUNY Campus: SUNY ESF

Presentation Type: Poster

Location: UU 111

Presentation #: 73

Timeslot: Session A 9:00-10:00 AM

Abstract: Lignin is the most abundant natural aromatic macromolecule on earth, but its complex chemical structure makes its applications challenging. Dehydrogenated polymer (DHP) is a synthetic lignin model that provides a fundamental understanding of lignin polymerization and characteristics. It can be synthesized from phenolic precursors in the presence of hydrogen peroxide and horseradish peroxidases such as horseradish peroxidase (HRP). The development process of enzymatic oxidative coupling allows one to analyze and understand the polymerization mechanism under controlled conditions. In addition, the synthesized DHP can be used as standardized lignin model compounds, to improve analytical precision and elucidate the reaction mechanism of lignin for its chemical and material applications. In the present study, the biosynthetic reaction of lignin monomer (i.e., coniferyl alcohol) was carried out by enzymatic polymerization in a system of hydrogen peroxide and 10 mM sodium phosphate buffer using horseradish peroxidase as a biocatalyst. The molecular weight distribution of the final polymer products will be determined by gel permeation chromatography (GPC) analysis. In addition, the structural properties of the synthesized DHP will be analyzed by nuclear magnetic resonance (NMR). Semi-quantitative analysis of DHP was conducted to measure the aromatic composition and inter-unit linkage contents of this polymer. The synthesized DHP will provide insights into the deep understanding of natural aromatic polymer (i.e., lignin) as well as free polymer synthesis and biocatalytic transformation approaches.