Araliopsis tabouensis

The major alkaloid of Araliopsis tabouensis is (+)-N-methylplatydesminium salt (see Vol. 6), and a study of the minor constituents has now resulted in the isolation of (+)-isoplatydesmine (2) and the pyranoquinolone (+)-ribalinine (folifine) (3).2... 

The same enantiomer occurs in Araliopsis tabouensis Aubrev et Pellegr. (45), and (—)-ribalinine has been found in the root bark of A. soyauxii Engl. (44). 

A quaternary alkaloid extracted by Boyd and Grundon (37) from leaves of Skimmia japonica Thunb. was shown to be the (+)-A/-methyl-platydesminium salt (51) by comparison with the racemate that had been synthesized earlier (27). The alkaloid has subsequently been isolated from Ruta graveolens (39) and from Araliopsis tabouensis (66). 

Halfordinine I 4,6,7,8-tetraOMe Araliopsis tabouensis [44], Diphasia angolensis [44], Halfordia scleroxyla [44], Melicope leptococca [18], M. perspicuinervia [44], Nematolepis phebalioides [28], Oricia suaveolens [44], Sarcomelicope argyrophylla [21], Teclea verdoorniana [44]... 

Veprisine ni 7,8-diOMe, 1-Me Araliopsis tabouensis (A. soyauxii) [23], Glycosmis mauritiana [43], Oricia renieri [44], Stauranthus perforatus [35], Vepris louisii [44], V. stolzii [44]... 

When heated briefly above its melting point, (+)-N-methyl-platydesminium iodide gave the 4-quinolone 52, [a]D + 82° (MeOH) (37), identified by comparison with the synthetic racemate (27). Higa and Scheuer (43) have now isolated from Pelea barbigera (Gray) Hillebrand quinolone 52, named isoplatydesmine. Araliopsis soyauxii has been shown to contain (+)-isoplatydesmine as the major alkaloid of the root bark (44) the same enantiomer is a constituent of A. tabouensis (45). 

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