Analysis of the essential oil from the roots of Eupatorium cannabinum subsp. corsicum (L.) by GC, GC‐MS and ¹³C‐NMR

Abstract

Eupatorium cannabinum subsp. corsicum (L.) is an endemic subspecies from the island of Corsica. The essential oil from the roots of this aromatic plant has been studied by GC, GC-MS and by 13C-NMR. In contrast to the essential oil from the aerial parts, which is dominated by hydrocarbon compounds (76.9%) and particularly by sesquiterpene components (43.3%), the essential oil from the roots was characterized by a high content of oxygenated compounds (61.0%), particularly oxygenated monoterpenes (54.0%). In the root oil, 106 components were identified representing 96.1% of the total amount. This oil was dominated by the monoterpenes esters (33%), the major components of which were neryl isobutyrate (17.6%), thymyl methyl oxide (15.1%), delta-2-carene (14.5%) and beta-pinene (5.7%). Aromatic esters, nerol derivatives (esters and diesters) and a benzofuran were investigated by GC-MS using different ionization modes including electron impact ionization, and positive- and negative-chemical ionization. These components have not previously been reported in the essential oil of aerial parts of E. cannabinum from Corsica island.

Antimicrobial activity and chemical composition of the essential oil of Hofmeisteria schaffneri

“…As thymol itself, the active compounds found in this work may destroy microbial cell integrity by different mechanisms [17–21] . The essential oils from several Lamiaceae and Asteraceae species, which are also rich in thymol analogs, possess similar high antibacterial action to the oil batches from H. schaffneri analysed in the present study [22–31] …”

“…From the chemotaxonomic point of view it is noteworthy that many species of the Eupatorieae tribe of the Asteraceae are used as anti‐infective agents in folk medicine and contain thymol and thymol ester derivatives [22] . So far these compounds have been reported in Doronicum corsicum , [23] Laggera pterodonta , [ 24] Schizogyne glaberrima , [25] Helichrysum arenarium [26] and some Eupatorium species [27,28] …”

“…Burdick & Jackson (Honeywell International Inc., Muskegon, MI) supplied dichloromethane. Sigma-Aldrich (Sigma-Aldrich Química, S.A. de C.V, Toluca, México) supplied standards of thymol (10), a-terpinene (11), m-cymene (12), p-cymene (13), linalol (14), linalyl acetate (22), a-terpinyl acetate (25), geranyl acetate (27), a-copaene (28), aromadendrene (31), alloaromadendrene (32), d-cadinene (35), E-nerolidol (36) and caryophyllene oxide (40), and the n-alkanes (C-7-C-40) used for the determination of the retention indexes. Hofmeisterin (1), 3′,4′,4a′,9a′-tetrahydro-6,7′-dimethylspiro[benzofuran-3(2H),2′-pyrano[2,3-b] benzofuran]-2,4a′-diol (2), hofmeisterins II and III (3 and 4), 2′,3′-dihydroxy-2′-thymyl angelate (6), 8,9-epoxy-10acetoxythymyl angelate (8) and euparin (50) were available from a previous investigation of Hofmeisteria schaffneri [1,2] while eupatoriochromene (49) was obtained from Helianthella quinquenervis.…”

Essential Oils and New Antimicrobial Strategies

“…In most cases, isolation is limited to major oil constituents. 1 H-NMR, 13 C-NMR, 2 D-NMR, IR and MS techniques provide data on the structural features of isolated oil constituents, leading to their characterization [59,[76][77][78][79]. Further, advanced Fourier transform-IR techniques are now used for the classification and quantification of essential oils and chemotaxonomy of essential oil bearing plants [80,81].…”

Thymol derivatives from essential oil of Doronicum corsicum L.

“…30 More recently, the thymol derivatives with oxygen functions (hydroxyl and esters groups) at the 8-and/or 9-and/or -10 positions 31 have been studied by IR, MS(EI and CI) and NMR ( 1 H and 13 C). As a part of our investigations on the characterization of the family Asteraceae (tribe Eupatorieae), 32,33 we have established that chemical ionization (PCI and NCI) with different reagent gases is an effective method for the identification of monoterpene esters derived from thymol, nerol, lavandulol and borneol.…”