Faculty Sponsor
Bruce Hamper
Final Abstract for URS Program
Humulones, the primary natural product present in the historically significant hop flower, represent a largely unexplored candidate for structure-based pharmaceutical design. Showing promising biological activity as an anti-bacterial and anti-inflammatory agent, humulones are of interest both for their bioactive properties and for their long-established tolerability and natural abundance. Humulones undergo a characteristic isomerization reaction, where the six-membered substituted phloroglucinol ring contracts to a five-membered ring isohumulone, under a variety of conditions, including those enabled by brewing conditions (thermal, metal-catalyzed) and by exposure to UV light. Optimization of the photocatalyzed isomerization of n-humulone to n-isohumulone in flow conditions resulted in a remarkably efficient and stereoselective reaction, producing in near-quantitative yields of largely trans-n-isohumulone (97%) under 400 nm light at 42 W at a flow rate of 1 ml/min. To further probe the stereochemistry of this reaction, naturally occurring (S)-n-humulone was racemized to near enantiomeric equivalence. The resulting mixture was then subjected to the established photoflow isomerization procedure and product distributions were analyzed by chiral chromatography, enabling stereochemical assignment of humulone and isohumulone configurations.
Presentation Type
Visual Presentation
Document Type
Article
Included in
Analytical Chemistry Commons, Food Chemistry Commons, Organic Chemistry Commons, Pharmaceutical Preparations Commons