Poster: Secondary Metabolism

Abs # 302: Genetic Characterization and Biological Activity of Extracts from Echinacea species.

Presenter:	Aoyama, Natsuyo , naoyama@csupomona.edu
Authors	Aoyama, Natsuyo  (A)   Still, David W (A)
Affiliations:	(A): Department of Plant Science, California State Polytechnic University, Pomona. Pomona, CA 91768

Echinacea species, collectively known as purple coneflowers, are native to North America and are distributed across a wide eco-geographic area. Although the mechanisms of their biological activities are largely unknown, they have been shown to stimulate the non-specific branch of the immune system. The supplements are taken to treat upper respiratory inflammation and they are one of the most popular herbal remedies in the United States and Europe. We are interested in establishing associations between the genetic structure of these taxa, secondary metabolites, and biological activity. Using AFLP to measure genetic diversity, we have shown that Echinacea taxa are distinct but closely related. Interspecific distances were approximately three times that of intraspecific differences and a NJ tree strongly supported two major clades. To establish biological activity of Echinacea species, we used representative taxa from both clades. Extracts were prepared from roots and aerial parts and subjected to microbroth dilution assays against gram positive and negative bacteria. Our results indicated that Echinacea extracts do not have antimicrobial activities against either gram negative or positive bacteria. Interestingly, E. purpurea root extracts interfered with synthetic beta-lactam antibiotics when the extracts and antibiotics were combined together. Furthermore, our results indicated that a presently uncharacterized protein acts as an inhibitor to specific antibiotic families that are in themselves beta-lactam inhibitors. Currently, we are isolating and characterizing this protein.