This research is supported in part by “Science Based Authentication of Dietary Supplements” funded by the Food
and Drug Administration grant number 1U01FD004246-03, the United States Department of Agriculture, Agricultural
Research Service, Specific Cooperative Agreement No. 58-6408-1-603-04. The authors thank Agilent Technologies for
provision of the analytical instrumentation and Dr. Vijayasankar Raman for authentication of the ginkgo plant samples.