MSU Bozeman scientists report new antibacterial compounds

The snakevine plant with its heart-shaped leaves is used in Aboriginal communities to dress wounds. (Kathleen Donald photo)
An Australian plant used in Aboriginal communities to dress wounds contains antibiotics that could be useful in agriculture and human medicine, according to research led by scientists at Montana State University-Bozeman.

by Annette Trinity-Stevens MSU News Archive

Four compounds were isolated from the snakevine plant and lab-tested against organisms that cause a variety of plant diseases as well as those that cause tuberculosis, anthrax, drug-resistant infections and malaria in humans.

The scientists must do more work before they know whether the compounds will work in humans, but their finding thus far have been reported in the journal Microbiology. The work also was featured in the news section of the Journal of the American Medical Association.

"A main source of antibiotics are streptomyces–bacteria which are usually found in the soil," said MSU plant scientist and study co-author Gary Strobel. "These are different streptomyces–we know that from their DNA sequences–and they have different chemistry, too."

Strobel named the compounds munumbicins after an Aboriginal man who showed Strobel trees and shrubs of medicinal interest in and around his community near Katherine, Australia.

Strobel travels widely to collect plant specimens and analyze them for new compounds. Nearly a decade ago, he co-discovered an alternative source of the anti cancer drug taxol from fungi living on a yew tree in Montana.

Microorganisms produce small chains of amino acids called peptides and other chemicals that are more complex than anything humans can make in the lab, Strobel said. Microbes that live in plants, which are called endophytes, need to be better explored not only for their uniqueness to science but also for their application in human medicine, agriculture and industrial processes, he said.

MSU has filed two patent applications on the munumbicins, and Novozymes Biotech, Inc. in California is sponsoring additional research–in both its labs and in Strobel’s–on the compounds.

It could be a decade or longer before any product is commercialized, assuming the compounds continue to show promise and can be fermented in large quantities, according to Debbie Yaver, research manager at Novozymes. The company has one year of testing to decide if it wants to formally license the potential antibiotics.

Initial tests show some toxicity among the compounds in their natural state, Yaver said.
Another issue is cost and whether the compounds could be manufactured at prices affordable to developing countries combating malaria, tuberculosis and other infectious diseases.

Yaver said her company adheres to an international framework for collecting in foreign countries established following the 1992 Earth Summit in Rio de Janeiro. Novozymes seeks permission before collecting in foreign countries, for example, and develops agreements to share any economic benefits with the country of origin.

Others involved in the project include Uvi Castillo, who actually isolated the organism and compounds, Eugene Ford and Joe Sears at MSU plus scientists from Brigham Young University, Harvard University, Brigham and Women’s Hospital and the Veterans Affairs Medical Center in Boise.

Novozymes, the National Science Foundation and the Montana Agricultural Experiment Station funded the research.

Contact: Gary Strobel, (406) 994-5148; Uvi Castillo, (406) 994-5147

http://www.montana.edu/commserv/csnews/nwview.php?article=775