Salviprzols A and B, C₂₁- and C₂₂-terpenoids from the roots of Salvia przewalskii Maxim.

Two C₂₁- and C₂₂-terpenoids, salviprzols A (1) and B (2), together with 24 known compounds including 17 diterpenoids (3-19), a triterpenoid (20), and 6 phenolic derivatives (21-26), were isolated from the roots of Salvia przewalskii Maxim. Salviprzols A and B represented a new subtype of C₂₃-terpenoids featured by an additional 2-oxopropyl moiety at C-12 and a rare γ-hydroxyl-α-methyl-α,β-unsaturated-γ-lactone ring system. Their structures were elucidated by extensive spectroscopic analyses, and the structure of 2 was confirmed by a single-crystal X-ray diffraction crystallography. The cytotoxic activities of the new isolates were tested. A plausible biosynthetic pathway for 1 and 2 was also proposed.