HYDROPHILIC INTERACTION CHROMATOGRAPHY ELECTROSPRAY MASS-SPECTROMETRYANALYSIS OF POLAR COMPOUNDS FOR NATURAL PRODUCT DRUG DISCOVERY

For the drug discovery efforts currently taking place within the pharm aceutical industry, natural product extracts have been found to provid e a valuable source of molecular diversity which is complementary to t hat provided by traditional synthetic organic methods or combinatorial chemistry. However, there exists a need for analytical tools that can facilitate the separation and characterization of components from the se sources in a rapid manner. Specifically, the evaluation of highly p olar compounds (i.e,, compounds that cannot be retained on traditional reversed-phase stationary phases) has been challenging, and a hydroph ilic interaction chromatography-electrospray ionization mass spectrome try (HILIC-ESI-MS) method was developed to meet this need. In this inv estigation, amide-, Polyhydroxyethyl Aspartamide-, and cyclodextrin-ba sed packings provided superior performance for the analysis of a set o f polar natural product compounds. The properties of the mobile-phase buffers also greatly impacted the separations, and relative to other v olatile buffering agents, ammonium acetate at a concentration of appro ximately 6.5 mM was determined to facilitate optimal HILIC retention, reproducibility, and durability. An optimized HILIC-ESI-MS system was successfully applied for the analysis of complex natural product mixtu res. The techniques described in this report should also prove useful for the analysis of polar compounds from synthetic sources of molecula r diversity such as combinatorial chemistry.