Associate Professor
Hamilton Hall 729
402.472.2998
ldu@unlserve.unl.edu

Du Research Group
Faculty & Research |  Faculty Directory |  Recent Publications

Current Research

1. Biosynthetic mechanism for mycotoxins and other bioactive natural products from pathogenic fungi
2. Discovery of new bioactive natural products from Lysobacter bacteria, plant endophytic fungi, and Chinese medicinal plants
3. Metabolic pathway engineering

Research in the Du group is at the interface of chemistry and biology. Specifically, we are studying how organisms (bacteria, fungi and plants) biosynthesize structurally complex, biologically active natural products. Our goal is to use this knowledge to produce new products through genetic engineering that will be beneficial to humans. The studies involve tools and knowledge from biochemistry, molecular biology, genetics, and chemistry. Currently, we are working on four main projects.

1. Biosynthetic mechanism for fungal polyketides Polyketides are probably the most significant group of natural products in terms of their importance to human medicines. To date, most of the studies have focused on polyketides isolated from bacteria. Although fungi produce numerous polyketides, their biosynthetic mechanism remains largely unknown. We have chosen a group of polyketides, including mycotoxin fumonisins and the cholesterol-lowering drug lovastatin (MervacorTM), as a model system for our studies. Below is a novel polyketide chain-releasing mechanism revealed by the study of the system.    

2. Genetics and function of novel antifungal natural products  Here, we are studying the molecular mechanism for the biosynthesis of a group of structurally unique antifungal metabolites, the tetramic acid-containing macrolactams. We have cloned the biosynthetic genes, generated gene disruption and gene replacement mutants, and heterologously expressed the genes. These works establish the foundation for future exploitation of this group of natural products as new fungicides or antifungal drugs.

3. New Anticancer Natural Products from Plant Endophytic Fungi   Plant endophytic microorganisms represent an unexploited resource for new bioactive natural products. Our current efforts are to identify the biosynthetic genes and mechanism for two anticancer compounds, mycoepoxydiene and deacetylmycoepoxydiene, isolated from an endophytic fungus, Phomopsis sp, of costal mangrove plants.

4. Biosynthesis of Plant Cyclopeptides Plant cyclopeptides are a large group of small peptides isolated from the leaves, stem barks, roots, and seeds of a wide variety of plant species throughout the world. The peptides are present in many Chinese medicinal plants, and their potentials have not been well exploited because of the lack of knowledge in their biosynthetic origin and mechanism. Here, we are studying the origin and the biosynthetic mechanism of these cyclopeptides.