| Abstract: | Phytochemical investigation of Parinari capensis (Chrysobalanaceae) led to the isolation of three diterpene lactones 1–3. The structures of these compounds have been established by NMR spectroscopy and X-ray crystal-structure analysis. Addition of bromine onto the exocyclic methylidene group of 1 yielded the brominated derivative 1-Br . X-Ray analysis of 1-Br established unambiguously the absolute configuration, and 1 was then identified as the (4R, 9R)-10-hydroxy-13-methoxy-9-methyl-15-oxo-20-norkaur-16-en-18-oic acid γ-lactone. Diterpenes 2 and 3 were identified as the C(13)-demethoxylated and the C(13)-demethylated derivatives of diterpene 1 , respectively. Antifungal activity against Cladosporium cucumerinum was determined for 1–3 . |
