In vitro cytotoxic activity of abietane diterpenes from Peltodon longipes as well as Salvia miltiorrhiza and Salvia sahendica

Phytochemical studies on Peltodon longipes afforded the isolation of twelve known abietane diterpenes being the active principle. The main diterpene, 7α-acetoxyroyleanone exhibited a similar strong cytotoxic activity against a pancreatic and a melanoma cancer cell line as tanshinone IIa the main compound from Salvia miltiorrhiza. Structure-activity relationship study was undertaken including 21 structurally different abietane diterpenes.