[A diterpenoid quinone from Periploca forrestii].

Tanshinone II A, which was known unique to the salvia, was separated and purified by silica gel column chromatography and recrystallisation from an ethyl acetate-soluble portion (the anti-inflammatory active portion) of ethanol extract of Periploca forrestii. The diterpenoid quinone was obtained from the Periploca for the first time.