Underwater explorers

By Alex Piazza
apiazza@umich.edu

It’s 8 a.m. in Yanbu, Saudi Arabia as David Sherman gazes overboard to scan the visibility.

“The water is unbelievably clear,” he said. “You can see at least 100 feet straight down.”

An hour into his journey across the Red Sea, the 40-foot cruiser drops anchor and Sherman affixes his dive mask tightly around his head.

As he submerges into the 82-degree water, the University of Michigan medicinal chemist navigates 120 feet below the surface toward an old shipwreck surrounded by pristine coral, sponges, sharks and eels.

“Diving in the Red Sea is really a unique experience,” he said. “There aren’t huge rivers flowing into the Red Sea, which means there isn’t sediment being dumped in from terrestrial sources. It’s among the best in terms of water clarity and calm conditions, too. All things considered, the Red Sea represents a huge biodiversity that hardly gets investigated.”

That is, until November when Sherman traveled to Saudi Arabia with fellow Life Sciences Institute faculty member Georgios Skiniotis. An avid scuba diver, Sherman utilizes his passion for underwater exploration to find new drug candidates to treat infectious diseases and cancer.

Sherman performed 11 dives during his November stint in Saudi Arabia, and with each plunge, he collected dozens of sediment samples.

“These sediments provide us with a vast diversity of microorganisms, and these microorganisms provide the key molecules for our drug discovery program” said Sherman, a research professor in the Life Sciences Institute, the Hans W. Vahlteich professor of medicinal chemistry and associate dean for research and graduate education in the College of Pharmacy.

Hundreds of those sediment samples now reside in Ann Arbor, where in his lab in the Life Sciences Institute, Sherman and his colleagues test whether the marine microorganisms collected in the Red Sea can lead to a medical breakthrough. The initial results could come as early as March.

“Saudi Arabia provided us access to some very exciting biodiversity, which in turn enabled us to discover very interesting and unique medicinal agents that will be investigated to improve human health,” he said.

And while many scientists synthesize compounds and create new treatments in a lab, research shows that nearly two-thirds of all drugs currently used are derived partially or entirely from a natural source. That’s enough to keep Sherman underwater.

“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,” he 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.”

A recent trip to Costa Rica reaffirmed the importance of Sherman’s work, which is funded by a number of federal agencies, including the National Institutes of Health and the National
Science Foundation. There, he has collected microorganisms off the coast at Las Baulas National Marine Park and the remote islands of Isla Del Coco in an effort to yield new drug candidates to treat infectious diseases and cancers.

Sherman then returned to Ann Arbor, where he and his U-M colleagues extracted compounds from the sediment samples and added them to the growing chemical library in the Life Sciences Institute’s Center for Chemical Genomics.

Lab tests confirmed their discovery of new broad-spectrum antibiotics—baulamycin A and B—that are active against both Methicillin-resistantStaphylococcus aureus (MRSA), which causes more than 180,000 deaths a year in the U.S. alone, and the infectious disease and notorious bioterror weapon anthrax.

To learn more about Sherman’s trip to Saudi Arabia and see footage from his dives, click here.

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