Pelea barbigera

Higa, T. and Scheuer, P. J. 1974. Alkaloids from Pelea barbigera. Phytochemistry, 13 1269-1272. 

The hydroxydihydropyranoquinolone (—)-ribalinine (47) is a constituent of the trunk and root bark of Araliopsis soyauxii f the (+ )-enantiomer (folifine) was obtained earlier from Haplophyllum species and the racemate, which has been synthesized was isolated from B. riedelianum. (-l-)-Isoplatydesmine (43) has also been isolated from A. soyauxii and can be regarded as a new alkaloid since isoplatydesmine obtained recently from Pelea barbigera (cf. Vol. 6) probably is the... 

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). 

Edulinine from Casimiroa edulis may be formed from (+)-N-methylplatydesminium salt during isolation. (+)-Edulinine from Pelea barbigera is certainly an artifact, and was obtained only when base was employed during isolation the precursor, presumably (—)-JV-methyl-platydesminium salt, could not be detected (43). ( )-Edulinine is conveniently prepared by reaction of 4-methoxy-l-methyl-3-(3-methylbut-2-enyl)-2-quinolone with m-chloroperbenzoic acid and then with aqueous base, without isolating intermediates (2). 

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