An unusual pregnane derivative and dibenzylbutyrolactone lignans from Centaurea sclerolepis

Guaianolides and lignans from the aerial parts of Centaurea ptosimopappa.

The genus Centaurea L. (Asteraceae, tribe Cardueae, subtribe Centaureinae) comprises ca. 600 species distributed in Asia, Europa, North Africa and America (Hickey and King, 1981; Heywood, 1979). Turkish flora numbers 187 species, 114 of which being endemic (Davis, 1975; Davis et al., 1988; Wagenitz et al., 1988; Guner et al., 2000; Duran and Duman, 2000; Turkoglu et al., 2003). Centaurea ptosimopappa Hayek is an endemic species distributed in the Mediterranean and South-Eastern Anatolian regions of Turkey; widespread and locally frequent in the Amanos and Casus mountains (Davis, 1975; Reeves and Adiguzel, 2004). Aerial parts of C. ptosimopappa were collected in Hatay, the Amanos Mountain ab…