3-Bromomethyl-6,7-dimethoxy-1-methyl-1,2-dihydroquinoxaline-2-one. Application: Carboxylic acid derivatization for HPLC analysis.
Br-DMEQ is a highly fluorescent labeling reagent for carboxylates such as fatty acids and prostaglandins. Quinoxalinone compounds are formed by a reaction between 1,2-diamino-4,5-dimethoxybenzene and pyruvic acid. Br-DMEQ also reacts with pyrimidine bases of nucleic acids. Potassium carbonate and 18-crown-6 are necessary for carboxylate labeling with Br-DMEQ. The HPLC detection limit of saturated fatty acids with 3 to 20 carbons is 0.3 to 1 femtomoles per injection. The excitation and emission wavelength of labeled materials are 370 nm and 450 nm, respectively.