Additional diterpene ketones from Hypoestes forskalei

Abstract

The aerial parts of Hypoestes forskalei yielded three new fusicoccane diterpene ketones, named deoxyhypoestenone, dehydrohypoestenone and hypoestene. The structure and relative stereochemistry of the diterpenes were based on 1H and 13C NMR data, mainly 2D NMR experiments, including 1H- 1H long range COSY, 1H-13C long range HETCOR and 1H-1H NOESY correlations, as well as chemical derivation of deoxyhypoestenone to its corresponding 8(9)α-epoxy derivative.