New neryl esters from Helichrysum italicum (Roth) G. Don (Asteraceae) essential oil.

Helichrysum italicum (immortelle) is a dwarf aromatic shrub native to the Mediterranean region. The typical subspecies (italicum) produces an essential oil rich in neryl acetate and characteristic β-diketones, italidiones, highly valued in the perfume industry. As esters are an important group of aroma-active volatiles, herein the composition of the ester fraction of this immortelle chemotype essential oil was studied in detail. Chromatographic separation of Corsican immortelle essential oil enabled the discovery of numerous potentially olfactory-interesting esters of nerol and/or angelic acid, undetectable by direct GC-MS analyses of the unfractioned oil. Four esters of nerol and medium-chain branched fatty acids represent new natural products, while several other esters have a rather restricted occurrence in the Plant Kingdom.