The Synthesis of Deuterated Isohumulones for Use as Internal Standards in LC-MS Stable Isotope Dilution Assays

Humulones are compounds that are prevalent in the hops flowers (Humulus Lupulus) used in beer brewing. These compounds undergo isomerization during the brewing process, and the resulting isohumulones are considered to be the primary contributors to the bitter flavors present in beer. As such, quantifying their presence, and the relative presence of their homologs(n-, co-, ad-), is of great importance in the characterization of beer. In this effort, one of the homologs of humulone (co) was isolated before being subsequently isomerized and deuterated for the purpose of analyzing beer by stable isotope dilution assay mass spectrometry(SIDA-MS). The addition of this stable isotopically substituted isohumulone as an internal standard can potentially allow the comparative quantification of humulones, isohumulones, and oxidized humulinones present in a beer sample