Transitorine, a New Quinoline Alkaloid from Ephedra transitoria.

Abstract

Page 262: The authors wish to withdraw from the literature the trivial name "transitorine". This alkaloid is not of novel structure, since it represents an already known tautomer of kynurenic acid. The 4-keto tautomer of kynurenic acid is the preferred form in polar solvents (e.g., DMSO-d 6 , as used to determine the NMR spectra of "transitorine") (Leeson, P. D.; Baker, R.; Carling, R. W.; Curtis, N. R.; Moore, K. W.; Williams, B. J.; Foster, A. C.; Donald, A. E.; Kemp, J. A.; Marshall, G. R.

Kynurenic Acid in Honey from Arboreal Plants: MS and NMR Evidence

“…Among medicinal plants and natural products, KYNA has been found in the photosynthetic stem tissues of several Ephedra species [3], [4], and it has been proposed that it is biosynthesised through the kynurenine pathway like in mammals and insects [5].…”

Quinoline, quinazoline and acridone alkaloids

“…In last year's review, 25a it was pointed out that the ostensibly new alkaloid transitorine 17 from Ephedra transitoria was, in fact, merely the keto tautomer of the well-known compound kynurenic acid. This fact has now been recognised by the authors, 26 who have withdrawn the trivial name transitorine (which actually appeared as 'transtorine' in the original publication 27 ) from the literature.…”