Biosynthesis of Thermopsis Alkaloids from Carbon-14 Dioxide. Evidence for the Formation of the Pyridone Bases from Lupanine Via 5,6-Dehydrolupanine

Abstract

The observed relative rates and chronology of labelling of the alkaloids of Thermopsis rhombifolia and T. caroliniana following pulse feeding of 14CO2 were consistent with the formation of the pyridone bases from lupanine, via 5,6-dehydrolupanine. Rhombifoline appears to be the first of the tricyclic bases to be formed from the tetracyclic ones. No evidence was obtained for the formation of sparteine, casting doubt on its role in the formation of these alkaloids.

Production of Quinolizidine Alkaloids by Photomixotrophic Cell Suspension Cultures: Biochemical and Biogenetic Aspects1

“…Furthermore it was shown similarly, since in Thermopsis, a related that after feeding with "COz it was lupa-genus with a similar alkaloid pattern, nine which became labelled first [17]. 'TO, is incorporated into lupanine first The predominance of lupanine in cell and only afterwards into the a-pyridone alkaloids, which are thought to derive from lupanine [18].…”

“…The a-pyridone alkaloids such as anagyrine (XIII) are assumed to derive from lupanine via 5,6-dehydr~lu~anine (XII) as a key intermediate. In recent years 5,6-dehydrolupanine (XII) has been detected in many species in which both lupanine and a-pyridone alkaloids were present [18,21,221. In analogy to the biosynthesis of the alkaloids which derive from lupanine, a similar series may be constructed using anagyrine o r thermopsine as origin.…”

A Survey of Alkaloids in Spartium junceum L. (Genisteae-Fabaceae)

“…In these experiments rhombifo line appeared to be the first of the tricyclic bases to be formed from the tetracyclic ones [17], The oc currence of rhombifoline was already demonstrat ed in several other species of the Fabaceae with a-pyridone alkaloids [7,18,19]. The presence of the rhombifoline in young twigs of Spartium ju n ceum could be a further hint that this compound is the likely intermediate between the tetracyclic ana gyrine and the tricyclic compounds cytisine and N-methylcytisine.…”

Alkaloid variation in New Zealand kōwhai, Sophora species

“…To complicate this matter further, some trees contain both sparteine and lupanine (see Supplementary data). While there is precedent in the literature (Cho and Martin, 1971;Golebiewski and Spenser, 1988;Al-Azizi et al, 1994) for each of these pathways in the family Fabaceae, it is possible that the observed variability and differences in alkaloid profile may offer the plants an ecological advantage, such as an antiherbivory role (Harborne, 2001). Alkaloid variability in the New Zealand Sophora may have been the result of biotic influences such as plant-insect induced stress, which has been reported to lead to phytochemical diversification (Voelckel et al, 2008).…”