The gingko tree (Gingko biloba) is an ancient species whose leaves and nuts are used widely in traditional medicine and as a dietary supplement because of their well-document anti-oxidant properties. We have used an electron paramagnetic resonance (EPR) spin-trapping technique to analyze the aqueous extracts of gingko leaves that were collected over the course of an entire growing season. Because it is the most common biological radical, our primary focus was on the hydroxyl radical, a highly-reactive oxidant responsible for a range of unwanted chemical reactions in the body, including mutation of macromolecules such as nucleic acids, proteins, and lipids, leading to disease. We used Fenton chemistry to generate the hydroxyl radical and the spin-trap DMPO (5,5-dimethyl-1-pyrroline N-oxide) to form a stable adduct that could be detected and analyzed by EPR. The quenching capacity of aqueous leaf extracts was compared to that of ascorbic acid, testing under the same conditions. Using specific combinations of free-radical inducers and spin-traps, we were also able to analyze the ability of gingko leaf extracts to quench different oxygen, nitrogen, sulfur, and carbon-centered radicals.

Analysis of antioxidant properties of Gingko biloba leaves by electron paramagnetic resonance

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.