Mimicking enzymes, chemists produce large, useful carbon rings

Drawing inspiration from nature, University of Wisconsin-Madison chemists have discovered an efficient way to wrangle long, snaking molecules to form large rings - rings that form the backbone of many pharmaceuticals but are difficult to produce in the lab. The work may represent preliminary progress toward deciphering just how enzymes, honed by evolution, so efficiently produce natural compounds. More immediately, the new method could help researchers synthesize drugs that have large ring backbones, such as those for hepatitis. The research is published Dec. Nature prefers the disorder of a long, flexible molecule to the order of a constrained ring, which makes it notoriously difficult for chemists to coax large rings to form in the lab. "If the linear molecules get long enough, it's as if the ends don't know anymore that they're connected, and they're just as likely to bond with other molecules as they are to come together," says UW-Madison Professor of Chemistry Sam Gellman , the senior author of the report. Yet biological enzymes can easily bring these ends together and form rings of all sizes.