High-performance liquid chromatographic assay of isoquinoline alkaloid formation from reaction of biogenic amines and aldehydes.

To understand the role that tetrahydroisoquinoline formation may play in alcoholism and drug toxicology, high-performance liquid chromatography with electrochemical detection was used to monitor the overall rate of reaction, in pH 7.4 buffer, between the catecholamines (dopamine, alpha-methyldopamine, dihydroxyphenylpropanolamine, deoxyepinephrine, levodopa, alpha-methyldopa, epinephrine, levarterenol, ans isoproterenol) and acetaldehyde. The observed overall rate of reaction varied from 0.38 to 0.0013 liter/mole sec. In addition, the reaction rate of the neurotransmitter dopamine was measured for various aldehydes (formaldehyde, acetaldehyde, glyoxylic acid, paraldehyde, malonaldehyde, glyceraldehyde, and chloral hydrate). The observed overall rate of reaction varied from 5.3 to 0.0011 liters/mol sec. Penicillamine prevented formation of the tetrahydroisoquinoline alkaloids when initially present in concentrations equal to or greater than the aldehyde concentration.