UHPLC/UV/CAD/HRMS analysis of Ginkgo biloba extracts. An approach for comparison of similar botanicals

Our approach for comparing natural products uses UHPLC with UV, Charged Aerosol detection (CAD) and high resolution- MS. This allows for a comparison of complex mixtures with three distinctly different detectors, providing a wealth of data to define the nature and relative amount of those differences, on a constituent level. This was applied to a comparison of two raw materials sources of Gingko biloba (GB), a Standardized European GB extract and an extract obtained from the National Toxicology Program. Our approach allowed a macro-level and the constituent level comparison to dimension differences that could be related to safety, performance, or lot-to-lot variability. Macro level comparisons of chromatograms from the UV and CAD were manually assessed and judged to be more similar than dissimilar. The positive and negative ion MS traces were chromatographically aligned using SIEVE, scoring of 0.937 out of 1.000. The software revealed that SEGB had unique components that NTPGB did not contain, but that the reverse was not true. Unique analytes in SEGB eluted after 35 minutes (i.e., ginkgolic acids). Minor differences in relative amounts of constituents were observed between the two raw material sources prior to 35 minute retention time. Only three constituents showed an order of magnitude increase or more in signal in the NTP relative to the SEGB sample (myricetin rutinoside, myricetin glucoside and a quercetin rhamnosyl rutinoside isomer).