Team
Amy Wright
Susan Sennett
Hilaire Kemami Wangun
Jennifer Choate
Jill Roberts
Gail Samples
Lynn Robertson
LaTasha Amisial
Priscilla Winder
After the biologists identify an extract or Peak Library fraction that shows activity in one of the assays, the chemistry group begins the process of purifying the active compound(s) from the mixture. They use a process called bioassay-guided fractionation in which they work closely with the biology group to identify the compound(s) that cause the observed bioactivity. Compounds are typically separated using various forms of chromatography including thin layer chromatography, vacuum column chromatography, medium pressure liquid chromatography, size exclusion chromatography or high performance liquid chromatography. A process called dereplication is used to determine if the compound is new or known. In our laboratory dereplication is conducted using TLC, LC-MS, NMR, and HPLC with PDA detection and comparison to both a proprietary as well as commercially available databases. Once a pure compound is obtained, its structure is determined through spectroscopic methods including mass spectroscopy, infrared, ultra-violet, and nuclear magnetic resonance (NMR). In most cases, NMR is our primary tool and we use an array of one and two-dimensional experiments to define the structures. Where crystals can be grown, X-ray diffraction is used to define the structures. HBOI is fortunate to have state-of-the-art equipment including a Thermo Finnegan LTQ LC-MS and a JEOL ECA-600 MHz NMR Spectrometer to use in this research.
