Contribution to the Analysis of the Essential Oil of Helichrysum italicum (Roth) G. Don. – Determination of Ester Bonded Acids and Phenols

Abstract: The essential oil of Helichrysum italicum (Roth) G. Don (everlasting orImmortelle essential oil) was isolated by hydrodistillation and analysed by GC and GCMS.Forty four compounds were identified. The main components were α-pinene(12.8%), 2-methyl-cyclohexyl pentanoate (11.1 %), neryl acetate (10.4%), 1,7-di-epi-α-cedrene (6.8%) and other compounds. The oil was fractionated and ester-containingfraction was hydrolysed with KOH/H₂SO₄. The liberated volatiles were analysed by GCand GC-MS: three phenols and twenty seven volatile carboxylic acids were identified[70% low fatty acids (C₂-C₅), 15% C₁₀-C₁₂ acids and 15% other acids]. The main acidswere acetic acid (24.3%) propanoic acid (17.2%), 2-methylpropanoic acid (11.4%),dodecanoic acid (8.7%), 2-methylbutanoic acid (8.3%), (Z)-2-methylbutenoic acid(5.1%) and decanoic acid (4.6%). With respect to the identified bonded carboxylic acids,the minimal number of esters in the oil was twenty seven, but their overall quantity wasprobably larger due to different possible combinations of alcohols with acids to formesters. On the other hand, only six main esters were identified in the oil beforefractionation and hydrolysis.