ATLANTA—Georgia Institute of Technology researchers have discovered 10 new molecular structures with pharmaceutical potential in a species of red seaweed known as Callophycus serratus that grows in the shallow coral reef along the coastline of Fiji in the south Pacific Ocean. Some of these natural compounds have exhibited the potential to kill cancer cells, bacteria and the HIV virus, according to Georgia Tech research. Two of them exhibit anti-bacterial activity specifically towards antibiotic-resistant Staphylococcus aureus.
So far, Georgia Tech has published information about three of these compounds, called diterpene-benzoate natural product, in the Oct. 12 online issue of the American Chemical Society journal Organic Letters. Published papers on the other seven are forthcoming.
"We're only at the test-tube level so far," notes Dr. Julia Kubanek, a Georgia Tech assistant professor of biology, chemistry and biochemistry. "The next step is to discover how these compounds work and then to study them in a more complex model system."
But the compounds are promising, she says.
"These molecular structures are curious in the way carbon atoms are attached," Kubanek explains. "It's very unusual. They represent a new category of organic molecules. It's exciting as a biochemist to observe that living organisms have evolved the ability to synthesize such unique and exotic structures compared to other molecules typically produced by seaweeds."
It could also be exciting financially, at least in the long run. Bristol Myers Squibb is collaborating with Georgia Tech researchers to determine how some of these 10 compounds kill cancer cells. Meanwhile, Georgia Tech has filed a provisional patent to protect the discovery of these structures and small variations of them.
Kubanek readily admits that the chance of any of these 10 initial compounds becoming pharmaceutical blockbusters is small. For one thing, she says, the potency of these compounds, while significant enough to warrant study, is somewhat low—meaning that dosages necessary to do things like kill cancer cells might have harmful side effects on humans. In addition, the compounds aren't very specific to particular types of cancer cells.
"And, of course, the drug industry is often concerned with targeting specific cells both to avoid building resistance and to have less likelihood of harming healthy cells," Kubanek notes. "But the good news is that we're coming up with a second group of compounds now from this seaweed with a different structure but the same metabolic family, which means we should have another five to 10 structures soon to study. We hope that those compounds, or others to come in the future, will show greater potency and specificity to go along with the interesting apoptosis effects we're already seeing."
Although the Fijian work has the potential for financial benefits for Georgia Tech, Bristol Myers Squibb and perhaps other pharmaceutical companies, drug discovery isn't the only economic factor at play. The seaweed project is also aimed at coral reef preservation and economic development for Fijian villagers—with whom Georgia Tech is making direct agreements for rights to the seaweed, with Fiji's Ministry of Fisheries and Forests overseeing the process. So, if these natural resources become marketable drugs, the Fijian government and specific villages will benefit monetarily, Kubanek notes. Thus far, Georgia Tech has agreements in place with three villages.