Identification of chrysanthenyl esters from the essential oil of <i>Anthemis maritima </i>L. investigated by GC/RI, GC‐MS (EI and CI) and ¹³C‐NMR spectroscopy: chemical composition and variability

Abstract

INTRODUCTION: Anthemis maritima L. (Asteraceae) is a wild plant growing in Corsica and Sardinia. No previous studies of the chemical composition of A. maritima essential oil have been found. The oil contains two series of cis- and trans-chrysanthenyl esters for which the MS data are not present in available libraries and the 13C-NMR data are not reported in the literature. The determination of these compounds is a challenging problem since some of these esters are present in low concentrations and they exhibit very similar EI-MS. OBJECTIVE: To develop comprehensive strategies involving integrated techniques including CC, GC/RI, GC-MS (EI and CI), 1H- and 13C-NMR and hemi-synthesis for the identification of both series of chrysanthenyl esters in A. maritima oils. METHODOLOGY: Seventeen oil samples were prepared by hydrodistillation. A fine analysis of a pool of Corsican oils was conducted after repeated CC. A selected Sardinian oil was used as source of product for the hemi-synthesis of chrysanthenyl esters. The identification of these compounds was based on joint information from GC-MS (EI and CI), 13C-NMR and hemi-synthesis. RESULTS: Integrated analysis of Corsican and Sardinian oils allowed the identification of 124 components accounting for 83.3-91.6% of the total oil. With the aid of principal component analysis, oil samples could be divided in two groups. Among 16 chrysanthenyl esters identified, 12 were laboratory-synthesised and their 13C-NMR data are reported for the first time. CONCLUSIONS: The study illustrates the contribution of integrated techniques for the characterisation of unusual essential oils.