Variation in the Essential Oil composition of Rosmarinus officinalis L. collected from different Spanish locationsin the Andalucia region
OM Palomino1*, FVarela2,P Navarrete2, M P Gómez-Serranillos1,T Ortega1, ME Accame1 andMA Cases2
1Pharmacology Department,School of Pharmacy, Universidad Complutense de Madrid. Ciudad Universitaria s/n, 28040 Madrid, Spain
2Aromatic and Medicinal Plants Laboratory, Environment Department. SGIT. INIA. Ctra. La Coruña Km8, 28040, Madrid, Spain
There exist three rosemary species that naturally grow in the Iberian Peninsula: Rosmarinus officinalis L., R. eriocalyx Jordan & Four and R. tomentosus Hub.-Mor & Maire. R. officinalisis a spontaneous shrub growing along theMediterranean area; R. eriocalyx grows in a small region of Andalucia (Southern Spain), Algeria and Libya, while R. tomentosus grows in the provinces of Granada and Malaga (Andalucia). Moreover, the hybridation between the two later species and R. officinalis is rather frequent.
The differences between plants and oils composition have been previously correlated to differences in the substrate. In this work, plant material from spontaneous populations of R. officinalis was collected in different locations from the Spanish region of Andalucia: Almeria, Cadiz, Cordoba, Granada, Jaen, Malaga and Sevilla, in order to select those populations with the highest essential oil yield and the best profile according to the International Standard Limits on Oil of Rosemary (2nd edition, 2000).
The essential oils were obtained by hydrodistillation of the dried ground material in a Clevenger-like apparatus for 2h at atmospheric pressure on about 100g of sample. Time was measured from the falling of the first drop of distillate. For each sample two replications of each extraction were done. The essential oil yield was evaluated gravimetrically.
The composition and chemical polymorphism of the essential oils were analysed by GC with a Hewlett Packard 6890 Series instrument equipped with an FID and HP-5 capillary columns (30m x 0.25mm, 0.25μm film thickness), working with the following temperature program: 70ºC for ten minutes and then ramp of 3ºC/min to 220ºC; injector and detector temperature, 250ºC; carrier gas nitrogen was adjusted to a flow of 2ml/min. The samples were injected using the split mode (split ratio 1:30) and an injection volume of 0.2μL. Identification of α-pinene, camphene, β-pinene, myrcene, limonene, 1-8 cineol, γ-terpinene, p-cimene, bornil acetate, camphor, borneol, α-terpineol and verbenone was performed by comparison of their retention times with those of pure authentic samples and by means of their linear retention indices (LRI) relative to the series of n-hydrocarbons.
Samples from Almeria, Cadiz and Granada show a high essential oil content, with a mean value higher than 2%. 1-8 cineol, camphor and verbenone content in samples from Almeria, Cadiz, Cordoba, Granada and Malaga is within the demanded limits; camphor content in samples from Jaen is very low whereas verbenone content in samples from Cordoba is very high (5.7%).
The mean content in α-pinene and myrcene is very high whereas limonene content is very low in every studied sample from Andalucia, the highest value being 1.58% (samples from Malaga). Camphene content is also very low except for samples from Cordoba and Almeria.
Our results show a great diversity in the essential oil composition and generally most components have lower values than the inferior limits demanded by the International Standard (IS) quality rules.