Foliage diterpenes of Dacrydium Intermedium: identification,variation and biosynthesis

The major diterpenes in the foliage of Dacrydium intermedium have been identified as rimuene, ent-rosadiene, ent-beyerene, phyllocladene, ent-kaurene, sclarene and ent-sclarene. ent-Rosadiene and ent-sclarene have not been reported previously from natural sources. Considerable tree-to-tree variations are encountered and genetic control is proposed. Biosynthetic mechanisms are put forward to explain the presence of diterpenes of both enantiomeric series. A lack of mono- and sesquiterpenes in both D. intermedium and D. fonkii, which ties in with Quinn's proposed revision of the Dacrydium genus, is also noted.