Leishmanicidal, antiplasmodial, and cytotoxic activity of novel diterpenoid 1,2-quinones from Perovskia abrotanoides: New source of tanshinones

Cryptotanshinone (1), a quinoid diterpene with a nor-abietane skeleton, and three new natural products, 1 beta -hydroxycryptotanshinone (2), 1-oxocryp totanshinone (3), and 1-oxomiltirone (4), were isolated from roots of the I ranian medicinal plant Perouskia abrotanoides. Their structures were establ ished using homo- and heteronuclear two-dimensional NMR experiments, suppor ted by HRMS. The total amount of tanshinones isolated from dry roots of Per ovskia abrotanoides was about 1.5%. The compounds exhibited leishmanicidal activity in vitro (IC50 values in the range 18-47 muM). These findings prov ide a rationale for traditional use of the roots in Iran as a constituent o f poultices for treatment of cutaneous leishmaniasis. The isolated tanshino nes also inhibited growth of cultured malaria parasites (3D7 strain of Plas modium falciparum), drug-sensitive KB-3-1 human carcinoma cell line, multid rug-resistant KB-V1 cell line, and human lymphocytes activated with phytoha emagglutinin A (IC50 values in the range 5-45 muM). The toxicity of tanshin ones toward the drug-sensitive KB-3-1 and the multidrug-resistant KB-V1 cel ls was the same, indicating that the compounds are not substrates for the P -glycoprotein drug efflux pump.