1H and 13C NMR spectra were measured on a Bruker DPX 400 FT NMR spectrometer operating at 400.13 MHz for protons and 100.61 for carbon. Tetramethylsilane (TMS) was used as an internal standard; chemical shifts were recorded in ppm and coupling constants in Hz. Indole, 13; tryptamine, 14; tryptamine hydrochloride, 4; and DMSO-d6 (99.9 atom %D) were purchased from Aldrich Chemical Co., USA. For the syntheses of compounds 5 to 12 see reference 6.