A New Clerodane Diterpenoid Isolated from Propolis

Abstract

Abstract A physiologically active substance has been isolated from Brazilian propolis and charac­terized as a new clerodane diterpenoid, as indicated by human hepatocellular carcinoma HuH 13 cell cytotoxicity assays. This compound inhibited growth of the hepatoma cells at a concentration around 10 μg/ml and arrested the tumor cells at S phase as revealed by flow cytometry. At higher concentrations it exerted lethal damage. The compound showed cyto­toxicity on human lung carcinoma HLC-2, HeLa, KB and rat W3Y cells, whereas human diploid foreskin and primary rabbit kidney cells were less affected.