ANN ARBOR, Mich.—Many scientists look for new drugs by synthesizing compounds in their laboratories. David Sherman dives for sea sponges and sediment off the coast, islands and reef systems of Papua New Guinea in the South Pacific.

Though medicine has a long history of making drugs based on naturally occurring materials, like antibiotic penicillin that comes from mold, Sherman said most of those efforts have focused on dry ground.

"We’ve barely scratched the surface of what’s out there," said Sherman, a medicinal chemist at University of Michigan.

Sherman heads to the Solomon Sea in December with a dozen scientists and about half as many crew members. They will dive two or three times a day. After dinner every night, one of the scientists will lecture about his or her specialty. U-M doctoral student Nathan Magarvey will be part of the two-week trek, Dec. 8-23.

Sherman chooses dive sites with high biodiversity and collects organisms that have promise as anti-cancer drugs. Sponges, for example, produce a wide array of biologically active materials he’s interested in, and he also looks at algae, corral rubble and sediments from shallow- and deep-water environments.

He works with geologists and geophysicists to examine the oceanography and determine how old an area of the ocean is, and with sponge taxonomists to help him keep track of what’s been studied elsewhere. After collecting materials, it’s microbiology, genetics and biochemistry that help his team understand the possibilities.

Sherman collaborates with the National Cancer Institute and Novartis Oncology for his research and has high hopes for the cancer-fighting potential of the materials he brings up. One of the field’s most exciting recent cancer leads was found from a unique actinomycetes bacterium collected near a remote island in the Bismarck Sea.

Sponges and their microbial symbionts, which are found near sponges and which live inter-dependently with sponges, also have been providing many compounds that respond to specific cancer targets, he added. Several are currently in clinical trials and one limitation continues to be adequate access to source material. Sherman hopes work like his will produce large amounts of a desired compound, limiting the need to return to pristine environments to collect materials.

The natural materials hold such great promise because humans, though capable of remarkable feats, can’t begin to generate the amazing, rich complexity of what happens in nature, Sherman said. "Bacteria are fantastic organic chemists. We can spend three years making a compound that bacteria can make in three seconds as a natural part of their metabolism," he said.

Sherman’s fascination with how aquatic microorganisms make products that might lead to anticancer compounds began by serendipity—as an undergraduate at University of California at Santa Cruz, he took a scuba class and organic chemistry at the same time. He still collaborates with his undergraduate adviser, professor Phil Crews.

Sherman is the John G. Searle Professor of Medicinal Chemistry, College of Pharmacy; a professor of chemistry, College of Literature, Science and the Arts; and professor of microbiology and immunology, Medical School.

Related links:

Sherman’s faculty profile More about Papua New Guinea National Cancer Institute

Sherman’s faculty profileMore about Papua New Guinea