Three New Diterpenoids from Salvia przewalskii MAXIM

Three new compounds including one ortho-quinone-type icetexane diterpenoid, i.e., przewalskin E (1), one abietane dinorditerpenoid. i.e., przewalskin F (2), and one 7,20-epoxyabietane diterpenoid. i.e., przewalskin G (3), were isolated from Salvia przewalskii MAXIM. The identification and structure elucidation of these compounds were based on 1D- and 2D-NMR spectral-data analysis. It is noteworthy that przewalskin E (1), featured with an 11,12-dioxoicetexane skeleton, represents the second example of a naturally occurring ortho-quinone-type icetexane diterpenoid from Salvia plants.