Abietane diterpenoids from Salvia pachyphylla and S-Clevelandii with cytotoxic activity against human cancer cell lines

A phytochemical study has been carried out on the aerial parts of Salvia pachyphylla and S. clevelandii. From S. pachyphylla, the known diterpenes carnosol (2), rosmanol, 20-deoxocarnosol (3), carnosic acid, isorosmanol (4), 7-methoxyrosmanol, 5,6-didehydro-O-methylsugiol (5), 8 beta-hydroxy-9(11),13-abietadien-12-one (6), 11,12-dioxoabieta-8,13-diene, and 11,12-dihydroxy-20-norabieta-5(10),8,11,13-tetraen-1-one were isolated, together with the new diterpene pachyphyllone (1). From S. clevelandii, the known diterpenes rosmadial (7), 16-hydroxycarnosol (8), abieta-8,11,13-triene, and taxodone were obtained, together with carnosol (2), rosmanol, and carnosic acid. The structure of the new compound (1) was identified on the basis of spectroscopic data analysis. Several of these compounds (1-8) were evaluated against a small panel of human cancer cell lines.