The Phenyl- and Biphenyl-Quinolizidines of In-Vitro-Grown Heimia salicifolia

Abstract

Under the conditions delineated in this paper, alkaloid synthesis was not detectable in heterotrophic callus and suspension cultures of Heimia salicifolia. However, in vitro-grown shoots are active in alkaloid biosynthesis, yielding the biphenylquinolizidine lactones vertine (1), lytrine (5), and lyfoline (7), the ester alkaloids demethoxyabresoline (14) and epidemethoxylabresoline (11), the phenylquinolizidinols demethyllasubine-I (10) and demethyllasubine-II (12), and several minor alkaloids that had not been previously shown to occur in H. salicifolia.

The biosynthesis of plant alkaloids and nitrogenous microbial metabolites

“…This has been the subject of careful examina t i ~n . ~~ It was shown first that a mixture of ~-[2,6-~H]tyrosine and ~-[U-'~C]tyrosine was incorporated into (S)-reticuline (29) and (5')-coclaurine (45) in leaves of Annona reticulata. Both alkaloids had similar 3H/14C ratios, which were close to the theoretical value (which shows that L-tyrosine was incorporated in the expected way and without degradation).…”

“…Further, it was found that, in A . reticulata, ~-[ring-U-'~C]tyrosine was used, similarly for the two halves of coclaurine (45) and reticuline (29); the ratios were, respectively, 1 :4.9 and 1 :4.7. Thus the two alkaloids must have one and the same biosynthetic origin.…”

“…This may be explained as the consequence of the large pool of dopamine found in the leaf Since radioactive norlaudanosoline and norcoclaurine led to browning of the leaves if they were fed to plants, (8-[0-methyl-''C]coclaurine [as (45)] was examined as a precursor. It was found to be an efficient (2.6 %) and specific precursor for (8reticuline (29) in Annona reticulata [the (R)-isomer of coclaurine was not incorporated]. The (S)-coclaurine was also an efficient precursor, in calli of Fumaria capreoluta, for reticuline and all benzylisoquinolines in the culture.…”

Germinación y multiplicación de plantas in vitro DE Heimia salicifolia (LYTHRACEAE)

“…Su floración es amarilla con dos centímetros de diámetro, formada por seis pétalos en pares a la porción axilar de la hoja y semillas de 0.5mm de diámetro, que en ambientes óptimos su germinación se produce entre los 10 y 16 meses. (Rother, 1985).…”