3,4,5-Trimethoxyphenylacetaldehyde, an Intermediate Metabolite of Mescaline, Is a Substrate for Microsomal Aldehyde Oxygenase in the Mouse Liver.
Kenji Watanabe, Yuichiro Kayano, Tatsuo Matsunaga, I. Yamamoto, H. Yoshimura
Biological and Pharmaceutical Bulletin 1995 DOI: 10.1248/bpb.18.696 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Experimental study Peer reviewed |
|---|---|
| Population | Mouse hepatic microsomes and mice |
| Interventions | mescaline 3 4 5-trimethoxyphenylacetaldehyde SKF 525-A metyrapone disulfiram antibody against CYP2C29 |
| Topics | Mescaline |
| Keywords | Microsome Metabolite Cytochrome p450 Biochemistry Isozyme Reductase Microsoma Enzyme Hydroxylation Stereochemistry |
| Citations | 9 |
| Key findings | CYP2C29 catalyzes the NADPH-dependent oxidation of 3,4,5-trimethoxyphenylacetaldehyde to 3,4,5-trimethoxyphenylacetic acid in mouse hepatic microsomes, and the deaminated metabolites of mescaline are much less active or inactive in cataleptogenic effect and sleep prolongation compared to mescaline. |
Abstract
3,4,5-Trimethoxyphenylacetaldehyde, an intermediate metabolite of mescaline, was oxidized to 3,4,5-trimethoxyphenylacetic acid by mouse hepatic microsomes. The reaction was NADPH-dependent, and inhibited by SKF 525-A, metyrapone and disulfiram. A P450 isozyme in mouse hepatic microsomes, P450 MUT-2 (CYP2C29), catalyzed the reaction (0.96 nmol/min/nmol P450) in which NADPH and NADPH-cytochrome c reductase were essential for the catalytic activity. The reaction was confirmed to be an oxygenation since molecular oxygen was incorporated into the carboxylic acid metabolite formed under oxygen-18 gas by GC-MS analysis. By addition of antibody against CYP2C29 to the microsomes (3.2 mg/mg microsomal protein) the MALDO activity was inhibited by 35% of the control value with preimmune serum, suggesting that CYP2C29 or an immunologically-related isozyme(s) plays a major role in the NADPH-dependent oxidation of 3,4,5-trimethoxyphenylacetaldehyde to 3,4,5-trimethoxyphenylacetic acid by mouse hepatic microsomes. Pharmacological experiments on mescaline and its deaminated metabolites using mice indicated that the metabolites were much less active or were inactive in cataleptogenic effect and pentobarbital-induced sleep prolongation as compared with the parent compound.