<p> The biosynthesis of the alkaloids of Decodon verticillatus, (L.)Ell, a member of the Lythraceae family, was studied by tracer methods. These alkaloids contain a phenylquinolizidine system, whose biosynthetic origin has not previously been investigated.</p> <p> Labelled samples of lysine, △^1-piperideine and phenylalanine yielded radioactive decodine and decinine, the two major alkaloids of D. verticillatus. Systematic degradations of these labelled alkaloids show that lysine, △^1-piperideine and phenylalanine serve as specific precursors. Whereas lysine and △^1-piperideine entered the quinolizidine ring, the biphenyl ring system of these alkaloids was derived from two units of phenylalanine. In a further experiment, labelled pelletierine was administered to the plants. But this experiment yielded an inconclusive result.</p> / Thesis / Doctor of Philosophy (PhD)

Cryogenine's immunosuppressive activity was first evaluated by Kosersky, et al. (21) who, impressed by the drug's ability to inhibit both the irritant- and immune- mediated phases of adjuvant-induced polyarthritis (11), quantitatively confirmed this activity and clearly differentiated the action of cryogenine from that displayed by 6-mercaptopurine. A definitive study by Watson and Malone (22) confirmed cryogenine's lack of immunosuppressive capacity at effective anti-inflammatory dose levels. The molecular complexity of the lythraceae alkaloids suggests that several active centers may account for their unique pharmacological profile. To assess these potentially active sites, two standard models of acute inflammation were selected for use in this present study -- the carrageenan-induced rat pedal edema assay and the croton oil-induced mouse ear edema assay. While the oral anti-inflammatory capacity of several of the lythraceae alkaloids has been well documented, their topical antiphlogistic capacity has not been evaluated. Moreover, the specific function or functions of the molecule which account for this anti-inflammatory capacity remain a mystery. The present study was undertaken: (i) to asses the topical anti-inflammatory potential of cryogenine, lythrine and two selected lythraceae intermediates and (ii) to investigate the possible molecular compounds which produce this established, yet enigmatic anti-inflammatory effect.