Phytoecdysteroids from Ajuga macrosperma var. breviflora roots.

Three new phytoecdysteroids, ajugacetalsterones C (1) and D (3) and breviflorasterone (2), were isolated from the roots of Ajuga macrosperma var. breviflora along with five known compounds, namely, 20-hydroxyecdysone, cyasterone, makisterone A, 20-hydroxyecdysone 3-acetate, and 20-hydroxyecdysone 2-acetate. The structures of 1-3 were elucidated on the basis of extensive 1D and 2D NMR spectroscopic studies. The new compounds possess acetal oxygen bridges between C-26 and C-20/C-22, or C-26/C-23, or a lactone bridge between C-26 and C-23.