Ecdysteroids from Cyanotis longifolia Benth. (Commelinaceae)

Cyanotis longifolia Benth. (Commelinaceae) contains ecdysteroids, which are highly concentrated in the roots and flowers, whereas leaves contain only very low amounts and stems intermediate amounts. 20-Hydroxyecdysone is the major component found in all tissues, but roots also contain large amounts of 20-hydroxyecdysone 3-acetate and ajugasterone C. A preparative experiment has shown that roots contain a complex ecdysteroid mixture, and the analysis of minor components has allowed the isolation of several already known ecdysteroids (polypodine B, 2-deoxy-20,26-dihydroxyecdysone, isovitexirone, poststerone) together with five new (ajugasterone C 3-acetate, 5beta-hydroxy-poststerone, poststerone 2-acetate, 14(15)-dehydro-poststerone 2-acetate, 24-epi-atrotosterone A [=24-methyl-ajugasterone C]) ecdysteroids that have been fully characterized. A preliminary investigation of 55 species belonging to 15 different genera of the Commelinaceae has shown that several of them contain significant concentrations of ecdysteroids, among which some previously uninvestigated ones appear to be very promising sources of ecdysteroids.