Preparation of Isomerized α-Acid Standards for HPLC Analysis of Iso-α-Acids, rho-Iso-α-Acids, Tetrahydro-Iso-α-Acids, and Hexahydro-Iso-α-Acids

摘要

Simple and convenient methods for making stable isomerized α-acid standards for the HPLC analysis of iso-α-acids, rho-iso-α-acids, tetrahy- dro-iso-α-acids, and hexahydro-so-α-acids are demonstrated. These HPLC standards are produced using the commercially available products As starting materials. The iso-α-acid, rho-iso-α-acid, and hexahydro-iso- α-acid standards are dicyclohexylamine salts. The tetrahydro-iso-α-acid standards are prepared by simple recrystallization from hexane.