Different isolation methods for determination of composition of volatiles from Nigella damascena L. seeds.

Volatile organic compounds (VOCs) from seeds of Nigella damascena L. were isolated using different techniques. The yield, as well as the qualitative and quantitative composition of the oils, was strongly influenced by the isolation method. In the hydrodistilled essential oil, the major components were the sesquiterpene hydrocarbons beta-elemene (59.1%), beta-selinene (12.8%) and alpha-selinene (12.6%). Conventional solvent extraction, followed by hydrodistillation, resulted in a volatile oil with a different composition than that of the hydrodistilled oil. The extracted oils predominantly contained sesquiterpene hydrocarbons, but also methyl anthranilate derivatives. By means of HS-SPME, it was possible to analyze not only sesquiterpenes and anthranilates, but also monoterpenes and the most volatile compounds, for example, the lower fatty acid (butyric, capronic) esters, which determine the characteristic sweet scent of N. damascena seeds. Using all testing methods, 55 compounds were identified, 40 of which are new for N. damascena seed VOCs.