Recognized for making natural products more efficiently

Chemist Chaitan Khosla of Palo Alto, Calif., will be honored on March 28 by the world's largest scientific society for finding innovative ways to use microorganisms to make natural products more efficiently. He will receive the American Chemical Society Award in Pure Chemistry at the Society's national meeting in San Francisco.

Khosla, a chemistry and chemical engineering professor at Stanford University, focuses on substances people find useful.

"They're important because many things that save our lives, like drugs, and save our crops' lives, like agrochemicals, started off as natural products," he explained. "And for chemists, they're interesting because they're so complicated. We'd love to figure out how nature makes them so well and emulate that."

The hurdles are twofold, said Khosla. First, "natural products are hideously large, unwieldy molecules. How do you work on building one part of it in a laboratory without the reactivity of another part getting in the way?"

Khosla's solution is to let nature do it. He and his group have developed ways of genetically "hijacking" the biochemical pathway a bacterium naturally uses to make the antibiotic erythromycin, for example. By removing a step here, adding one there or altering another, researchers custom-make a new pathway in what Khosla calls "a biologically friendly organism."

Secondly, most organisms do not naturally make compounds in sufficient quantities to harvest for human use -- think of TAXOL and the yew tree, he said. "So our idea is basically to take out the entire genetic step from that organism and put it in a biologically friendly one that's easy and quick to grow. It's the equivalent of bringing the mountain to the prophet." Some researchers are taking this approach to producing epothilone, a promising natural anti-cancer agent -- perhaps even more so than TAXOL® -- found in a very
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Contact: Christina Curtin
c_curtin@acs.org
202-872-4400
American Chemical Society
21-Mar-2000