Chemical variability and antioxidant activities of spontaneous and cultivated Rosmarinus officinalis essential oils according to the geographical origin of their exploited organs

ABSTRACT

The present study described the variation of the chemical composition of different organ essential oils from cultivated and spontaneous Rosmarinus officinalis collected from some regions of Southern Tunisia at the flowering and the vegetative phases. Antioxidant activities were evaluated using DPPH• radical-scavenging activity and reducing power. Essential oils were isolated by hydrodistillation and analyzed by GC/FID and GC/MS. Twenty-nine compounds were identified representing from 88.7% to 99.3% of the total essential oils. Five chemotypes were assigned to different organ essential oils (camphor, camphor/borneol/α-terpineol/α-eudesmol, camphor/borneol/α-terpineol, camphor/borneol/bornyl acetate/α-eudesmol and camphor/borneol/α-terpineol/caryophyllene). Furthermore, the essential oils presented interesting antioxidant potential in DPPH^• radical-scavenging (IC₅₀ = 0.093–0.623 mg/ml) and Fe³⁺ reducing power (EC₅₀ = 0.121–0.523 mg/ml) assays. Understanding the chemical composition of essential oils in relation to environmental factors and plant organs is a crucial quality criterion for their marketing and helps to maximize their potential application.

KEYWORDS:

• Antioxidant activity
• chemical composition
• essential oils
• geographical origin
• Rosmarinus officinalis

Acknowledgments

We gratefully acknowledge the Ministry of Higher Education and Scientific Research (Tunisia), the French National Centre for Scientific Research (CNRS, France), the Ministry of Higher Education Research and Innovation (MESRI, France) and the French National Research Agency (ANR-10-LABX-33, Labex LERMIT, France) for their financial support. Karine Leblanc and Soumia Rharrabti (BioCIS, France) are warmly acknowledged for their technical support. Our thanks are due to Pr Nacim Zouari (ISBAM, Gabes University) for his kind help in revising the English.

Disclosure statement

No potential conflict of interest was reported by the author(s).