Further chemical examination of the constituents in the bark of Croton lechleri led to isolation of two new diterpenoidal compounds, korberin A and korberin B. Their structure was elucidated by H-1 and C-13 NMR spectroscopic methods, and they were shown to be diterpenoid lactones with the clerodane skeleton. Their antibacterial activity was tested using a direct bioautographic TLC assay.