Baltic amber is a potential source of new antibiotics.

Humans in the Baltic countries have used ancient amber (fossilized tree resin) for medicinal purposes for centuries. Infants there today are given amber necklaces that they chew to relieve teething pain, and people put pulverized amber in elixirs and ointments for its purported anti-inflammatory and anti-infective properties.

Now researchers from the University of Minnesota have pinpointed compounds that help explain Baltic amber’s therapeutic effects and that could lead to new medicines to combat antibiotic-resistant infections.

“New drug scaffolds are urgently needed for pain, inflammation, and infectious disease,” said Elizabeth Ambrose, PhD, associate professor, department of medicinal chemistry, U of M, during a session at the online spring meeting of the American Chemical Society this week.

“Molecules in fossils, often from extinct species, undergo biotransformations over millions of years that lead to novel structures.”

Ambrose and her team say they knew from previous research that there were substances in Baltic amber that might lead to new antibiotics, but they had not been systematically explored. “We have now extracted and identified several compounds in Baltic amber that show activity against gram-positive, antibiotic-resistant bacteria,” she continues, calling Baltic amber a “med chem treasure trove.”

Ambrose’s interest originally stemmed from her Baltic heritage. While visiting family in Lithuania, she collected amber samples and heard stories about their medicinal uses. The Baltic Sea region contains the world’s largest deposit of the material, which is fossilized resin from now extinct pines, formed about 44 million years ago.

“We are excited to move forward with these results,” Ambrose says. “Abietic acids and their derivatives are potentially an untapped source of new medicines, especially for treating infections caused by gram-positive bacteria, which are increasingly becoming resistant to known antibiotics.”