Peyoruvic acid

This pathway to anhalonidine has now been shown to be essentially correct by in vivo experiments.33 Administration of [l,9-14C]peyoruvic acid (44) to peyote cacti resulted in an efficient and specific incorporation of activity into the alkaloid, without a change in isotopic ratio. The status of the amino-acid as a true intermediate was confirmed by chemical analysis to show that it is present in the peyote cactus. Further support for Scheme 5 was provided by incubation of [9-14C]peyoruvic acid (44) with fresh peyote slices. Carbon dioxide was evolved and on work-up the decarboxylation product was found to be the imine (45), specifically labelled with 14C at C(9). The production of the imine rather than the tetrahydroisoquinoline (43) suggests that the decarboxylation may be an oxidative process and this interesting reaction deserves further investigation. 

It is known that anhalonidine is derived via peyoruvic acid (57), but this was not noted in the above study. However, the related amino-acid (58), which is found in L. williamsii, was shown later to be incorporated into salsoline (55) in E. merkei. ... 

Attention was next turned to the two amino acids which have recently been found in peyote, namely peyoxylic and peyoruvic acids. Administration of labeled peyoxylic and peyoruvic acids to the plant led to the specific incorporation of the labels in anhalamine and anhalonidine, respectively. ... 

Finally, the facile decarboxylation of peyoruvic and peyoxylic acid was observed when incubated with fresh peyote slices. In the case of labeled peyoruvic acid, the 3,4-dihydroisoquinoline 18 was isolated from the decarboxylation mixture. It is interesting to note in this respect that Bobbitt and coworkers have recently found that simple tetrahydroisoquinoline-1-carboxylic... 

The above results confirm that simple tetrahydroisoquinolines such as anhalamine and anhalonidine are formed in nature from 3-demethylmescaline. 3-Demethylmescaline condenses with glyoxylic or pyruvic acid to give pey-oxylic or peyoruvic acid. These amino acids undergo decarboxylation to supply 3,4-dihydroisoquinolines which are then enzymatically reduced to the tetra-hydroisoquinolines. ... 

Lophophora williamsii (Lem.) Coulter Anhalamine (+N-acetyl and N-formyl), anhalidine, anhahnine (+N-formyl), anhalonidine (+N-formyl), anhalonine (+N-acetyl and N-formyl), anhalotine, isoanhalamine, isoanhalidine, isoanhalonidine, isopeUotine, lophophorine, lophotine, 0-methyl-anhalonidine, peUotine, peyophorine, dehydroan-halamine, dehydroanhalidine, dehydroanhalonidine, dehydropeUotine, peyoruvic acid, 0-methyl-peyoruvic acid, peyoxylic acid, 0-methylpeyoxylic acid... 

The dehydroderivatives of the main phenolic alkaloids and the glyoxylic and pyruvic acid condensation products, peyoruvic acid and peyoxyhc acid, are interesting in the light of biosynthetic considerations, as these compounds may be intermediates in the biogenetic transformation of phenethylamines into tetrahydro-isoquinolines (cf. Lundstrom 1983). 

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