David A.H. Taylor

Limonoids from Australian members of the Meliaceae

Abstract The seeds of Owenia acidula of Owenia venosa were found to contain a simple limonoid and a derivative of the cyclopropane protolimonoid glabretal, which has also been found in the timber of Aglaia ferruginea . The timber of Toona australis was found to contain cedrelone, and the timber seed of Xylocarpus moluccensis ( sensu Mabberley) have been found to contain a rich mixture of limonoids. The chemotaxonomic significance of these results is discussed.

Limonoid extractives from Xylocarpus moluccensis

Abstract Further examination of the timber of Xylocarpus moluccensis has given three new compounds, xyloccensins G, H and I. Structures are deduced for G an

Limonoid extractives from Aphanamixis polystacha

Abstract The seed of Aphanamixis polystacha has been found to contain a number of limonoids. Eight of these are now described; they are all of the ring A-lactone, ring B-cleaved, meliacan group and are closely related to the known prieurianin.

Limonoids from Nymania capensis

Abstract The bark and timber of Nymania capensis contain prieurianin and other complex limonoids, four of which have been identified. The chemical evidence serves to support the taxonomic position of Nymania in the family Meliaceae.

Diterpenes from the timber of 20 Erythroxylum species

Abstract Timber extracts of 20 species of Erythroxylum have been examined, yielding 31 known compounds and 12 new compounds which have been identified. Erythroxylum brevipes , E. cuneifolium , E. minutifolium , E. neocalidonicum , E. myrsinites and E . sp. nov. Guaricipo. did not appear to contain diterpenes, but only long-chain aliphatic material, which was not investigated. A preliminary investigation was made of E. ecarinatum (similar to E. pictum ), E. ellipticum , (similar to E. australe ), and E. rufum (unidentified diterpenes) but was not extended, due to shortage of material.

Ekebergin, a limonoid extractive from Ekebergia capensis

Abstract Seeds of Ekebergia capensis contain a crystalline limonoid to which the name ekebergin has been given. This has been identified as a diacylated methyl angolensate derivative.

Coumarins from Ekebergia pterophylla

Abstract The bark of Ekebergia pterophylla yielded atraric acid, β-amyrin, β-amyrone, oleanonic acid, β-sitosterol, β-sitosteryl acetate and the novel coumarins, pterophyllins 1 and 2. Extractives of the wood yielded the novel coumarins, pterophyllins 3–5. Lupeol was isolated from the hexane extract of the leaves.

Limonoids from the seed of the natal mahogany, Trichilia dregeana

Abstract We have investigated the seed limonoids of Trichilia dregeana and obtained the known rohituka-7, an ester related to polystachin, and four new compounds designated dregeana-1 to 4. These were found to be intermediate in oxidation level between rohituka-7 and heudelottin.

Protolimonoids from Turraea nilotica

Abstract Turraea nilotica has been found to yield a new protolimonoid, 24,25 epoxy-23-hydroxy-7-tirucallen-3-one, which we name niloticin, together with two closely related compounds. No limonoids were found.

Diterpenes from the timber of Erythroxylum pictum

Abstract Extracts of timber of Erythroxylum pictum yielded sitosterol and 29 diterpenes, of which 15 are new. These include a small group of 4,5- seco -ro