Maroccanin: A New g -lactone and Other Constituents from Centaurea maroccana Ball. (Asteraceae)

A new g -lactone named maroccanin (1) together with 5 known compounds : scopoletin (2); 8 a -[2’-hydroxymethyl-2’-butenoyloxy]-dehydromelitensin (3); 11,13-dehydromelitensin (4); 8 a -[2’-hydroxymethyl-2’-butenoyloxy]-sonchucarpolide (5) and 5Hα,6Hβ,7Hα,-15-hydroxy-8α-( 1’,2’-dihydroxyethyl-acryloxy)-elema-1(2),3(4),11(13)-trien-6,12-olide (6), were isolated from the chloroform soluble part of the aqueous-MeOH extract of the flowering aerial parts of C.maroccana Ball. (Asteraceae), an endemic species of the North of the Sahara. The structures were established by chemical and spectral analysis, mainly HR-ESIMS, HREIMS,UV and NMR experiments (COSY, NOESY, HSQC and HMBC). The compounds 3 and 5 are new for the genus Centaurea .