Tetrahydro-β-carbolines, potential neuroactive alkaloids, in chocolate and cocoa

Tetrahydro-beta -carbolines (TH beta Cs), potential neuroactive alkaloids, were found in chocolate and. cocoa. 6-Hydroxy-1-methyl-1,2,3,4-tetrahydro-beta -carboline (60HMTH betaC), 1,2,3,4-tetrahydro-beta -carboline-3-carboxylic acid (THCA), 1-methyl-1,2,3,4-tetrahydro-beta -carboline-3-carboxylic acid (MTCA) in both diastereoisomers (1S,3S and 1R,3S), and 1-methyl-1,2,3,4-tetrahydro-beta -carboline (MTH betaC), 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 TH betaC, the concentration ranges were determined: 60HMTH betaC (0.16-3.92 mug/g), THCA (0.01-0.85 mug/g), 1S,3S-MTCA (0.35-2 mug/g), 1R,3S-MTCA (0.14-0.88 mug/g), and MTH betaC (nd-0.21 mug/g). The highest content was generally found in chocolates and cocoas, but cereals containing chocolate also showed an appreciable amount of TH beta Cs. The possible biological implications of this novel group of alkaloids in chocolate are discussed.