The Separations/Structure/Bioavailability core will provide a resource for the extraction, fractionation andstructural determination of phytochemicals. The core will build upon the experience gained by the Krausgroup in the preparation of standards and structural identification of phytochemicals plus the experiencegained by the Murphy group in the extraction and fractionation of Echinacea and Hypericum samples.Extraction, fractionation and structural determination/standard preparation will be conducted in closepartnership with individual projects within the Center. Bioavailability studies will be conducted on bioactivecompounds to determine if these chemicals are absorbed and reach relevant cellular targets.Our objectives are to:1. Provide project researchers with extracts of medicinal plants including Hypericum, Echinacea andPrunella vulgaris. Ultrasonication and Soxhlet extraction methods will be compared to determine whichmethod provides the most useful extracts.2. Fractionate bioactive extracts to determine if activities separate into specific or multiple fractions.Collection of compounds of interest across gradients on HPLC will be a primary fractionation strategy.3. Determine the structures of individual components of medicinal plants. A combination of spectroscopicmethods (IR, NMR, mass spectroscopy)4. Provide standards for chemical fingerprinting and testing. The preparation of herbal compound standardsthat are not commercially available will be based upon novel methods for synthesizing Echinacea alkamide-related ketones and a patented method for procyanidin synthesis developed by the Kraus laboratory. Othersynthetic approaches will be developed as needed for compounds of important bioactivity.5. Determine the bioavailability of extracts, fractions and components. CaCo-2 cells will be used as a modelfor human intestinal uptake and metabolism of herbal compounds of interest, as well as interactions betweenfractions that may alter compound uptake. Glucuronide conjugates are expected to be major and lessbioactive metabolites from herbal phenolics; the inducibility of glucuronide metabolism by herbal componentswill also be studied.
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