SOME ASPECTS OF TRITERPENE BITTER PRINCIPLE BIOSYNTHESIS

Summary

The triterpene bitter principles are reviewed in order to understand their biogenesis. A derivative of 3–hydroxy lanost–24–ene–11–one is suggested as the source of the cucurbitacins. The limonoids, meliacins and Simarubaceae bitter principles are all considered to be derived from 3α–hydroxy–8β–methyl–(13α, 17βH, 20αH) lanosta–14,24–diene. This has its side chain degraded to a furan in the limonoids and meliaçins. Biological Baeyer Villiger oxidation of ring A and D is considered to occur in the limonoids and of ring B, C, and/or D in the meliacins. With the Simarubaceae bitter principles the side chain may be degraded, but this is entirely lost by lèavage of the 12,17–β–dicarbonyl system.