Pentaceras australis

In 1952, Haynes et al. (7) isolated an alkaloid from Pentaceras australis (Rutaceae) grown in Australia. This alkaloid, with the molecular formula C14H8N2O, was named canthin-6-one (1). Giesbrecht et al. (2) later isolated a new type of alkaloid, 3-methoxycanthin-2,6-one (2), from Simaba cuspidata of Brazil. Then Ohmoto and Koike (5) isolated... 

Methylthiocanthin-6-one (6) is one of the first canthin-6-one alkaloids isolated from the bark (stem, root, branch, and sapling) and wood of Pentaceras australis (31) together with 1 and 7 (5). Readers are referred to Volume 3 (p. 249) of this treatise for its structure (5). 

Hortia braziliana Vel. Pentaceras australis Hook. f. Zanthoxylum (Xanthoxylum) budrunga Wall. c e... 

The development of the chemistry of the eburnamine alkaloids all from apocynaceous plants was greatly facilitated by the know ledge which had been accumulated on tire canthin-6 ones, bases originally isolated from Pentaceras australis (Rutaceae) and more recently from simarubaceous plants. For this reason a short discussion of their chemistry is in order. 

Canthin-6-ones. From Pentaceras australis, three optically inactive coloured alkaloids were isolated. The structure of canthin-6-one followed from its analytical data, physical properties and potassium permanganate oxidation to j8-carboline-l-carboxylic acid and synthesis from 5-methoxycanthin-6-one vide infra). (Chart 10.2). 

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