Composition and bioactivity of Pluchea carolinensis (Jack.) G. essential oil from Martinique

Abstract

Pluchea carolinensis (Jacq.) G. Don (Asteraceae) is a plant species still widely used in the popular medicine of Caribbean region. The present work describes the chemical composition of essential oil of P. carolinensis leaves and flowers from Martinique Island and first exploration of its antimicrobial and insecticide activities. The chemical analysis using GC/FID and GC–MS of essential oils of P. carolinensis flowers and leaves led to the identification of 44 constituents representing 64.6–84.2 % of the extracts. The major identified components in aerial parts were selin-11-en-4α-ol (17.7–33.4 %), β-caryophyllene (5.5–21.1 %), 2,5-dimethoxycymene (8.9–3.3 %), caryophyllene oxide (6.6–3.3 %), α-pinene (4.7 %) and spathulenol (3.8–3.1 %). Furthermore, two carvotanacetone derivatives were for the first time identified from the aerial parts of P. carolinensis: 5-angeloyloxycarvotagetone (2.9–18.1 % of abundance in oils) and the new carvotanacetone 5-isovaleroyloxycarvotagetone (1.2–7.0 % of abundance in oils). Their structures were elucidated based on NMR and HRMS data. Essential oil of P. carolinensis exhibited an antimicrobial activity against Aspergillus niger, Candida albicans, Staphylococcus aureus and Bacillus cereus. Insecticidal assays against Aedes aegypti showed an interesting repellent activity at 1.0 % and a high irritating activity at 0.1 % against mosquitoes. Thus the essential oil from P. carolinensis aerial parts can be considered as new source of natural ingredient for pharmaceutical and cosmetical industries.