Volatile components of Centaurea calcitrapa L. and Centaurea sphaerocephala L. ssp. spaerocephala, two Asteraceae growing wild in Sicily

The volatile components of the flowerheads of Centaurea calcitrapa L. (C.c.) and Centaurea sphaerocephala L. ssp. sphaerocephala (C.s.) were obtained by hydrodistillation and identified by GC and GC-MS. Altogether 96 components were identified, 66 in C. calcitrapa and 68 in C. spaerocephala, mostly fatty acids (32.8%, C.c. and 44.2%, C.s.) and hydrocarbons (32.3%, C.c. and 15.9%, C.s.). 9,12-Octadecadienoic acid (15.8%, C.c.) and hexadecanoic acid (30.7%, C.s.) were the most abundant fatty acids; tricosane (8.0%, C.c.) and heptacosane (4.9%, C.s.) were the main hydrocarbons. Sesquiterpenes were also present as hydrocarbons (10.1% for 14 components in C.c. and 9.2% for 13 components in C.s.) and as oxygen-containing sesquiterpenes (2.0% for four components in C.c. and 13.6% for nine components in C.s.).