Fourteen constituents were isolated from the roots of Salvia miltiorrhiza f. alba. Two of them were new compounds and were named 1,2,15,16-tetrahydrotanshiquinone (I) and tanshinaldehyde (II). The others were identified as Ro-090680 (III), dihydroisotanshone I (IV), danshexinkun B (V), miltirone
Tanshinone IIA, the major component extracted from Radix salvia miltiorrhiza, has been observed to possess various kinds of pharmacological activities including antioxidant, prevention of angina pectoris and myocardial infarction and anticancer. Tanshinone IIA was incubated with rat liver microsomes