Tetrahydro-β-carbolines, Potential Neuroactive Alkaloids, in Chocolate and Cocoa
J. Agric. Food Chem., 2000, 48 (10), pp 4900–4904

Tetrahydro-β-carbolines (THβCs), potential neuroactive alkaloids, were found in chocolate and cocoa. 6-Hydroxy-1-methyl-1,2,3,4-tetrahydro-β-carboline (6OHMTHβC), 1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (THCA), 1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (MTCA) in both diastereoisomers (1S,3S and 1R,3S), and 1-methyl-1,2,3,4-tetrahydro-β-carboline (MTHβC), besides serotonin and tryptamine biogenic amines, were identified and quantified in dark chocolate, milk chocolate, cocoa, and chocolate-containing cereals by RP−HPLC−fluorescence and HPLC−MS. For each THβC, the concentration ranges were determined:  6OHMTHβC (0.16−3.92 μg/g), THCA (0.01−0.85 μg/g), 1S,3S-MTCA (0.35−2 μg/g), 1R,3S-MTCA (0.14−0.88 μg/g), and MTHβC (nd-0.21 μg/g). The highest content was generally found in chocolates and cocoas, but cereals containing chocolate also showed an appreciable amount of THβCs. The possible biological implications of this novel group of alkaloids in chocolate are discussed.

Keywords: Chocolate; cocoa; alkaloid; tetrahydro-β-carboline; β-carboline; biogenic amine