2013 Annual Report
American ginseng (Panax quinquefolius) is far more expensive than Asian ginseng (P. ginseng) on the world market. Consequently, adulteration of American by Asian ginseng is common. FCMDL has developed an analytical method using a simple methanol-water extraction and direct analysis using flow injection mass spectrometry that can detect as little as 2% adulteration by Asian ginseng. In addition, a software model was developed that permitted adulterated spectra to be predicted based on the spectra of the pure American and Asian ginseng.
Anthocyanins are common flavonoids that have been linked to resistance to cancer, diabetes, infections, inflammation, and neurological diseases. Scientists at USDA in Beltsville, MD, analyzed purple radishes (Raphanus sativus L.), a plant bred to provide high anthocyanin content, by high performance liquid chromatography ( HPLC) with high resolution mass detection (HRMS). The method detected 57 acylated anthocyanins, 45 for the first time. This study showed the presence of a large variety of anthocyanins and the necessity of HPLC-HRMS to provide the sensitivity and specificity for their identification.
The popularity of botanical supplements to augment the US diet has provided a strong economic impetus for adulteration. Ginkgo biloba extract is a frequently used supplement that purportedly provides enhanced cognitive function. Scientists at USDA in Beltsville, MD, measured 22 flavonol glycosides in three NIST reference materials (SRM 3246, 3247, and 3248) and 20 commercially available supplements using HPLC-MS. Half of the commercial supplements were found to be adulterated with one of two inexpensive compounds (quercetin or quercetin rutinoside). Analysis was easily accomplished with a simple methanol-water extraction and direct analysis by UV spectrophotometry. This method provides the analyst with an inexpensive method for detecting adulterants.
Samples of ten plants (sorghum, black beans, red beans, purple grape skin powder, soybeans, black cohosh, eggplant, corn flour, and broccoli) were extracted with three solvents (hexane, ethyl acetate, and methanol-water. All samples will be analyzed by HPLC-MS. This project will elucidate the extraction steps necessary for metabolomic profiling of plant materials.