Confirmation of the enantiomers of 1-methyl-1,2,3,4-tetrahydroisoquinoline in the mouse brain and foods applying gas chromatography/mass spectrometry with negative ion chemical ionization

With the aid of a new chiral derivatizing reagent and a sensitive and specific assay using capillary gas chromatography/negative ion chemical ionization mass spectrometry, the proportions of R and S enantiomers of 1-methyl-1,2,3,4-tetrahydroisoquinoline (1MeTIQ) in mammalian tissues and foods were studied. R- and S-1MeTIQ enantiomers derivatized with a chiral derivatizing reagent, perfluoro-2-propoxypropionylchloride, were clearly separated. The ratio of enantiomers was R/S = 0.24, 0.55 and 0.60 in wine, cocoa and mouse brain. S-1MeTIQ predominated in all samples. This result suggested that 1MeTIQ could be formed at least partially through an enzymatic mechanism.