Lycopodium tristachyum

Arabidopsis thaliana Nicotiana tabacum Solanum tuberosum Stellaria longipes Helianthus annuus Trit icum aes t ivum Pinus pinaster Lycopodium tristachyum Rhodotorula mucilaginos. Anabaena variabilis Nos toc punc t i f orme Conserved sites Conserved sites (plants)... 

Lycopodine.—Lycopodine (4) is formed in Lycopodium tristachyum from lysine [via A -piperideine (2)] and acetic acid, " The labelling pattern observed with these precursors suggests that lycopodine (4) could be formed simply from two molecules of pelletierine (5) but in this case Occam s Razor does not apply since radioactive pelletierine (5) labels only one of these pelletierine units in lycopodine (4). - The hypothetical pathway proposed to take account of these results has been tested in further experiments.Piperidine-2-acetic acid (6), as its CoA ester, is one of the hypothetical intermediates but the evidence obtained most strongly points to it not being involved in lycopodine biosynthesis, [carftoxy- C]Piperidine-2-acetic acid fed in admixture with DL-[4- H]lysine [as (1)] gave lycopodine with a C ratio... 

Work on the biosynthesis of lycopodine (126) in Lycopodium tristachyum and cernuine (127) ° in L. cernuum, previously published in preliminary form and reviewed,has appeared in full lycopodine and cernuine.It was established that the two alkaloids are derived from two molecules of lysine via a symmetrical intermediate which is in all probability cadaverine. The hypothesis that the Lycopodium alkaloids were modified dimers of pelletierine (125) (Scheme 12) required reappraisal, as pelletierine gave only one each (shown with heavy bonding) of the two CgN units of (126) and (127). 

In the interpretation of these experiments in Lycopodium tristachyum the argument could be made, as had been in the case of (15), that the preference for cleavage of the C4 unit over intact incorporation was a consequence of higher reaction rates for the former rather than the latter process. We had rejected this explanation in the case of (15) on the basis of the argument that if an intact C4 unit was a precursor for the acetate derived C3 fragment, it would surely not all have been cleaved and at least some of the 4 precursor should have survived. In the case of lycopodine, however, we did see an opportunity to probe the status of acetoacetate as a precursor which did not require the feeding of a C4... 

While for developing of simple piperidine alkaloids, e.g., pelletierine (Punica granatum), piperine (Piper nigrum et longum), and lobeline (Lobelia inflata), only one molecule of lysine is necessary, for quinolizidine alkaloids - e.g., lupinine (Lupinus luteus), sparteine of antiarrhythmic activity (Sarothamnus scoparius), and cytisine of respiratory stimulant effect (Laburnum species) - two molecules of lysines are indispensable. It was also proved that lycopodine (Lycopodium tristachyum, clubmoss) of quinolizidine structure has no polyketide origin, but it is a modified dimer of pelletierine, which, in turn, is derivable from lysine and acetate. 

Hemscheidt and Spenser conducted feeding experiments on the Lycopodium alkaloids using the club moss Lycopodium tristachyum (73,74). The acetate-derived C3 fragments, C-6-C-8 and C-14—C-16, of lycopodine (92) were introduced into the alkaloid via acetonedicarboxylic acid (87). Therefore, lycopodine (92) was generated through an intermediate 91 produced by condensation of 4-(2-piperidyl)acetoacetic acid (89) and pelletierine (90), in which both units were derived from the condensation... 

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