The heartwoods of two species of South African
Euphorbiaceae have been chemically investigated.
From Cleistanthus schlechteri three new diterpenes
possessing the hitherto unknown ent-isopimara-8(14),15-diene
skeleton were isolated. By means of chemical and
spectroscopic methods these were shown to be 3a-hydroxy-ent
isopimara-8(14),15-diene, I, 3a-hydroxy-ent-isopimara-
8(14},15-dien-12-one, II, and 3a,12a-dihydroxy-ent-isopimara-
8(14),15-diene, III. A biogenetic sequence has been
proposed in which it is suggested that these compounds are
probably the precursors of the major diterpenoid,
cleistanthol, IV, previously isolated from this source.
From the second species, Spirostachys africana, a
new diterpenoid seco-acid, spirostachic acid, VIII, was
obtained in addition to the beyerene derivatives previously
reported. Mass spectral fragmentation patterns of the
seco-acid and its methyl esters proved to be useful as a
diagnostic tool in structure elucidations. / Thesis (Ph.D.)-University of Natal, Durban, 1971.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ukzn/oai:http://researchspace.ukzn.ac.za:10413/10888 |
| Date | January 1971 |
| Creators | McGarry, Joan Margaret. |
| Contributors | Candy, H. A. |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
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