Description_x000D_ Application_x000D_ Dihydrotanshinone I, a lipophilic diterpenes, may be used in comparative analysis versus other lipophilic diterpenes such as cryptotanshinone (CTs), tanshinone I (TsI), tanshinone IIA (TsIIA) and tanshinone IIB (TsIIB) to assess its relative protective effect against processes such as reperfusion neurotoxic ischemia. Dihydrotanshinone I may be used as a reference compound during the analysis or purification of lipophilic diterpenes from biological materials. Dihydrotanshinone I may be used to assess it radiosensitization potential in cancer chemotherapy._x000D_ Packaging_x000D_ 10 mg in glass bottle_x000D_ 50 mg in poly bottle_x000D_ Biochem/physiol Actions_x000D_ Tanshinone extracted from a herb, Salvia miltiorrhiza, commonly used in Chinese traditional medicine. A significant decrease in tumor growth was observed using dihydrotanshinone I and irradiation treatment with mouse xenograft model.