Structural Studies of Kaurane Diterpenes From Ryparosa acuminata (Flacourtiaceae)

Two new diterpenes have been isolated from the twigs of Ryparosa acuminata ( Flacourtiaceae ), and identified as 16α,19-dihydroxykauran-20-oic acid δ- lactone and 16α-hydroxykaurane-19,20-dial. Friedelin and eudesmin were also isolated. The structure of the lactone was confirmed by X-ray crystallography.