Endogenous alkaloids in man, part 31. Identification of the dopaminergic neurotoxin 1-trichloromethyl-1,2,3,4-tetrahydro-beta-carboline in human blood after intake of the hypnotic chloral hydrate

1-Trichloromethyl-1,2,3,4-tetrahydro-beta-carboline (TaClo), a potent toxin toward dopaminergic neurons, readily originates in vitro from the biogenic amine tryptamine and the unnatural aldehyde chloral. For this reason, this heterocycle has been postulated to be formed endogenously in humans after administration of the hypnotic chloral hydrate or after exposure to the ind ustrial solvent trichloroethylene by a spontaneous chemical ring closure re action, In this paper, we report on the first identification of TaClo in bl ood samples of patients treated orally with chloral hydrate, Using a specif ic and sensitive gas chromatographic screening procedure based upon electro n-capture and mass-selective detection, TaClo was determined after conversi on to its volatile trifluoroacetyl derivative. The identity of TaClo in hum ans was clearly demonstrated by GC-MS analysis in selected-ion-monitoring m ode, by the characteristic chlorine isotopic pattern of the molecular ion, (C) 1999 Academic Press.