Extraction and Identification of Chemical Constituents of the Essential Oil of Rosa Species

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1 Extraction and Identification of Chemical Constituents of the Essential Oil of Rosa Species A. Younis 1, A. Riaz 1, M.A. Khan 1, A.A. Khan 2 and M.A. Pervez 1 1 Institute of Horticultural Sciences, University of Agriculture, Faisalabad, Pakistan 2 Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad, Pakistan Keywords: essential oil composition, solvent extraction, hydro distillation, citronellol Abstract Most of the rose species are used for ornamental purposes. However, a few of them exhibit the marked fragrance that is sought by perfumeries around the world. In present study four Rosa species i.e., Rosa species, Rosa damascena, Rosa centifolia, Rosa borboniana and Rosa 'Gruss an Teplitz' were used for essential oil through solvent extraction and hydro distillation. In present studies, through solvent extraction, Rosa damascena produced 39 g of concrete oil, which is 0.19% on petal weight basis. Rosa centifolia produced 30 g (0.15%) of concrete oil. Rosa borboniana and Rosa 'Gruss an Teplitz produced 19 g (0.09%) and 12 g (0.06%) of concrete oil respectively. When absolute oil from four Rosa species were compared it was found that Rosa damascena yields 29 g (0.14%) of absolute oil and the second highest yield 22 g (0.11%) of absolute oil was obtained through Rosa centifolia. Rosa 'Gruss an Teplitz' yielded least quantity of absolute oil. Through hydro distillation it is observed that from Rosa damascena yielded 31 g (0.155%) of concrete oil, and 26 g (0.13%) of absolute oil was recovered through distillation. Solvent extraction yielded more absolute oil (0.11%) as compared hydro distillation (0.075%) on petal weight basis. Through gas chromatography 13 different constituents were identified and characterized in rose essential oil. INTRODUCTION Roses have a long and colourful history and are symbols of love, beauty and devotion. The rose is, according to fossil evidence, 35 million years old. In nature, the genus Rosa has some 200 species spread throughout the Northern Hemisphere, from Alaska to Mexico and including northern Africa. Garden cultivation of roses began some 5,000 years ago, probably in China (Weiss, 1997; Gudin, 2000). Roses are commonly grown for ornamental purposes, however, there are some Rosa species having fragrance in their flower petals and are used to extract essential oils. Rosa damascena, Rosa gallica and Rosa centifolia are the most important species, producing high-value aromatic oil, generally called as Otto of rose, attar of rose or rose essential oil. This product is one of the best-known scents used in perfumery and is in demand of the industry. Rose oil is used primarily as a fragrance component in pharmaceutical preparations (e.g., ointments and lotions), and is extensively used as a fragrance ingredient in perfumes, creams, and soaps. Essential oils are complex and highly variable mixtures of constituents that belong to two groups: terpenoids and aromatic compounds. Hydrocarbons are almost always present in monoterpenes (Mondello et al., 2005). Although essential oils are comprised of many types of compounds, the major ones are monoterpenes (Seigler, 1998). Essential oil structures for synthesis and accumulation are located near the surface in glandular trichomes, secretory cavities or secretory canals of the plants (Bruneton, 1995). Essential oil can be extracted from plant materials by a number of procedures including steam distillation, vacuum distillation, solvent extraction, high-pressure CO 2 extraction, cold pressing, and hot pressing (Anac, 1984; Baser, 1992; Ruberto et al., 1999; Simandi et al., 1999; Lis et al., 1998; Anitescu et al., 1997; Laenger et al., 1997; Muzika et al., 1990). The composition of these oils can vary significantly with place of origin, harvest season, and weather. It is the type of plant material that determines which method will be used to obtain the essential oil (Veriotti and Sacks, 2001). Although the extraction Proc. XXVII IHC-S5 Ornamentals, Now! Ed.-in-Chief: R.A. Criley Acta Hort. 766, ISHS

2 method of essential oils may seem only to be of technical interest, it is one of the key points which determine the quality of the oil that is used, since a wrong or wrongly executed extraction, can damage the oil, and alter the chemical signature of the essential oil. Steam distillation has been the most common method of extracting essential oils. Steam distillation was done in a still with fresh or sometimes dried botanical material placed in the plant chamber of still, and pressurized steam was generated in a separate chamber and circulated through the plant material. The heat of the steam forces the intercellular pockets that hold the essential oils to open and release them. The temperature of the steam must be high enough to open the pouches, yet not so high that it destroys the plant tissue or fractures or burns the essential oils (Durst and Gokel, 1987; Wilson, 1995). Zoebelein (1997) reported that rose Otto (rose oil), is not a distilled oil as this would seriously damage the petals and the essence obtained from them, but it is a blend of decanted and recovered oil. The rose essential oil can be extracted by using solvent extraction method (Hexane), stream distillation and high-pressure CO 2 techniques. Solvent distillation is more frequently used to extract the aroma of rose blossoms using a chemical solvent, such as hexane, to saturate the plant material and pull out the aromatic compounds. This renders a waxy, light brown, semi-solid material, called concrete. The concrete can then be dissolved in alcohol to remove the solvent. When the alcohol evaporates, an absolute remains which is a reddish liquid with a typical rose odor. Solvent extraction yields about 10 times the amounts obtained by steam distillation, in the order of % (1-2 ml concrete/kg flowers) (Lawrence, 1991). In the present studies extraction of essential oil from four Rosa species, Rosa damascena, Rosa centifolia, Rosa borboniana and Rosa 'Gruss an Teplitz' was compared using different extraction methods with the aim to examine the differences in the oil contents in these Rosa species. Gas chromatography for the separation, characterization and quantitative analysis of essential oil was also carried out in present study. MATERIALS AND METHODS Collection and Preparation of Flowers Flowers of four Rosa species; Rosa damascena, Rosa centifolia, Rosa borboniana and Rosa Gruss an Teplitz were collected from the Rose Project Area, Institute of Horticultural Sciences, University of Agriculture, Faisalabad. Collection of flowers was carried out early in the morning before sun rise to avoid the loss of volatile oil. The flowers were plucked at full blooming stage and placed for overnight to remove excessive moisture. Methods of Essential Oil Extraction and Identification 1. Hydro Distillation. Hydro distillation is the common method of extracting essential oil from aromatic plants. Hydro distillation is done in a still. Fresh petals were placed in the plant chamber of the still, and pressurized steam is generated in a separate chamber and circulated through the petals. The heat of the steam forces the tiny intercellular pockets that hold the essential oil to open and release essential oil. The essential oil together with the steam molecules, travel through a tube into the still s condensation chamber. As the steam cooled, it condensed into water. All the vapours condensed and collected in receiver, the liquid called as hydrosols (rose water + oil). The rose water obtained from hydro distillation unit has a thin layer of rose oil on the surface of rose water. The thin layer of oil was recovered from hydrosols by using organic solvent (nhexane). Oil was separated from organic solvent (n-hexane) by using process of distillation in a recovery evaporator. Remaining traces of n-hexane were removed by bubbling nitrogen gas through this oil. Twenty kilograms of petals were used to obtain rose oil. 2. Solvent Extraction. For solvent extraction, Soxhelt s extraction apparatus was used. Twenty kilograms of rose petals from each species were placed in a porous thimble which 486

3 was placed within a cylinder (Jacket). N-hexane was vaporized through the side tube into the condenser, where vapors condensed and fell into the thimble thus extracting all the volatile compounds from petals. As the level of solvent and extracted volatile compounds in the jacket and siphon rose, after some time siphon sucked up all the solvent from thimble to the attached flask. In this way, all the volatile compounds come into the flask along with solvent. This product is called concrete oil. Concrete oil was further processed in order to get oil free from solvent. For this purpose a distillation process using a rotary evaporator was performed to recover solvent from concrete oil (organic solvent + Rose oil). Concrete oil added in round bottom flask of rotary evaporator. Temperature of rotary evaporator was set at 50 C. At this temperature, all the solvent distilled from concrete oil. Further solvent was recovered by increasing temperature of rotary evaporator. Distillation by using rotary evaporator is useful because this process does not lose the active ingredients of rose oil. Organic residue remaining in the flask of rotary evaporator was collected in another flask. To remove the moisture sodium sulphate was added in the organic residue and filtered. The last traces of solvents were removed by bubbling nitrogen gas through the oil. Absolute oil from concrete oil was recovered by adding 2 ml of absolute alcohol in concrete oil. The alcohol removes all the natural waxes present in the essential oil. The oil was filtered and absolute alcohol was removed by performing distillation process in the rotary evaporator. Remaining traces of alcohol were removed by bubbling nitrogen gas through this oil. These processes yielded absolute oil by using solvent extraction process. Three samples were run for each species. 3. Gas Chromatography (GC). Different constituents of essential oil of four Rosa species were characterized by using gas chromatography. In the present research Shimadzu C-R4A chromatopac was used as printer or platter. Gas chromatograph was Perkin-Elmer Model-3920 was used. The column was of glass with internal diameter (id) 2mm 2m which was packed with 10% SE-30 on chromsorb W AW mesh. Other conditions of analysis were, sample size 0.04 micro litre and nitrogen gas with flow rate was 25 ml/minute. Initial column temperature was 80 C and final temperature was 200 C, initial hold up time was one minute, final hold up time was 16 minutes. Hydrogen gas pressure was 20 psi and air pressure was 50 psi. Injected sample temperature was 200 C, flame ionization detector was used (FID) with 250 C temperature. Identification of continuants of Rose essential oil was done with gas chromatograms of mixtures of standards, while quantitative analyses were carried out by calculating area under the peak by using software CSW-32. ( Statistical Analysis The data were also analyzed statistically to find the significance of the results within the species and means were compared by DMR test at 5% probability (Steel et al., 1997). RESULTS Using the hexane solvent extraction method, the Rosa damascena produced 39 g of concrete oil [0.19% on fresh petal weight basis (PWB)] followed by the species Rosa centifolia that produced 30 g of concrete oil (0.15%). Rosa borboniana and Rosa Gruss an Teplitz produced 19 g (0.09%) and 12 g (0.06%) of concrete oil respectively (Table 1a). The yield of absolute oil and absolute oil percentage showed similar patterns in the Rosa species. The species Rosa damascena produced the highest absolute oil (29 g), which is 74.35% on concrete oil basis and 0.14% on PWB. Rosa borboniana and Rosa 'Gruss an Teplitz' produced 10 g (0.05%) and 7 g (0.03%) of absolute oil respectively. Through hydro distillation, it was observed that from Rosa damascena, 31 g of concrete oil was recovered, which is 0.155% on PWB; Rosa centifolia yielded 18 g of concrete oil, which is 0.09% on PWB; and Rosa borboniana and Rosa 'Gruss an Teplitz' produced 11g (0.06%) and 9 g (0.03%) of concrete oil respectively. The results showed that again Rosa damascena was at the top and the highest 26 g of absolute oil was recovered through 487

4 distillation, which is 83.87% on concrete oil basis and 0.13% on PWB. The second highest yield 15 g of absolute oil was obtained through Rosa centifolia which is 83.33% on concrete oil basis and 0.07% on PWB. From Rosa borboniana, 8 g (0.01%) of absolute oil was recovered whereas; Rosa 'Gruss an Teplitz' yielded the least 6 g (0.03%) quantity of absolute oil (Table 1b). Analysis of variance revealed that the mean squares due to different extraction methods were significant at P 0.01 for concrete oil. The mean squares were also significant (P 0.01) due to species and method x species interaction. The results of present studies showed that the hexane solvent extraction method appeared to be the best method. The quantity of oil through hexane solvent extraction was significantly different from hydro distillation. The species differed from each other with respect to oil yield and most importantly; different species had different oil yield from different extraction methods. It is appeared that hexane has more extraction power as compare to hydro distillation, as more concrete oil was recovered when hexane was used as solvent. Among the four species, the highest quantity of oil was recovered from the species Rosa damascena, which was significantly different from other three species. Rosa centifolia proved the second best species for yield of concrete oil followed by Rosa borboniana whereas, Rosa Gruss an Teplitz' yielded the least quantity. The interaction between extraction method and species was also highly significant. Different constituents of essential oil of Rosa species were determined by using gas chromatography. The components identified through gas chromatography in four Rosa species are listed in Table 2. In rose essential oil extracted through solvent (hexane) 13 components were characterized. The major components were citronellol, phenylethyl alcohol, methyl eugenol, geranyl acetate, rhodinyl acetate, benzyl alcohol and linalool. The four Rosa species were compared for the percentage composition of the components of essential oil. The percentage of citronellol (62.134%), which is principal constituent for fragrance, was highest in Rosa damascena. Oil extracted from Rosa centifolia was comprised of 54.74% of citronellol. Rosa borboniana and Rosa Gruss an Teplitz contained 27.23% and 12.85% citronellol respectively. The second major constituent of rose essential oil was phenylethyl alcohol. The highest percentage (47.23%) of this component was identified in Rosa Gruss an Teplitz followed by Rosa borboniana (40.23%). The least amount of phenylethyl alcohol was recorded in Rosa damascena (19.25%). Stood et al. (1994) identified 32 components by GC of rose essential oil which included citronellol (40%), geraniol (14.49%) and phenylethyl alcohol (4.06%). Other compounds were mostly presented in trace amounts. The detailed percentage composition of components of four Rosa species is presented in Table 2. DISCUSSION Extraction of essential oil from the four Rosa species, was carried out using different extraction methods. It is known that the chemical composition of the volatile oils isolated from aromatic plants depends strongly on the extraction method, among other variables (Muzika et al., 1990; Stashenko et al., 1996). More concrete oil and absolute oil was obtained through hexane solvent extraction as compared to hydro distillation. Hexane had more dissolving power for volatile compounds and yielded essential oil which contained relatively little wax, albuminous and colouring matter, but correspondingly more of the odoriferous compounds (Wang, 2000). The oil contents of four Rosa species under study ranged from 0.03% to 0.1%, which is in agreement with Kokkini and Vokon (1989) who reported 0.1% oil contents in Damask rose. The oil percentage in Rosa centifolia ranged from 0.075% to 0.11%. A range of 0.1-1% absolute oil was reported in Rosa centifolia by Karousou et al., (1998). Rosa damascena growing wild in Greece, ranged from 0.1% to 0.9% (Kokkini and Papageorgion, 1998). The difference in oil contents of the tested species in turn indicated the positive response for selection for oil contents. Hexane had the ability to dissolve all the odoriferous principles of the flower and possessed a low boiling point to permit its being easily removed (distilled off), without resorting to higher temperature. The odorous principles present in rose flowers 488

5 can be isolated more efficiently by extraction with volatile solvents than by hydro distillation. The concrete and absolute oil of rose can be extracted more efficiently by solvent extraction. Although hexane is the best solvent found so far for essential oil extraction from roses it posses some inherent disadvantages. There are relatively high solvent losses in the course of the extraction process, due primarily to evaporation of the low boiling point. On hydro distillation, Rosa damascena yielded more essential oil as compared to other three Rosa species. But the overall yield of essential oil through hydro distillation is not satisfactory as compared to solvent extraction. Many authors have reported that hydro distillation produces lower extraction yields (Simandi et al., 1999; Tuan and Iiangantileke, 1997). From our results it is also clear that the chemical constitution of the essential oil from Rosa species is affected by the technique of extraction. Both techniques, solvent extraction and hydro distillation yield essential oil with different percentage composition of the components, but hexane solvent extraction is to be preferred because it extracts superior essential oil with a higher extraction efficiency than the hydro distillation method. Literature Cited Anac, O Gas chromatographic analysis on Turkish rose oil, absolute and concrete. Perfumer & Flavorist 9:1-14. Anitescu, G., Doneanu, C. and Radulescu, V Isolation of coriander oil: Comparison between steam distillation and supercritical CO 2 extraction. Flavour Fragrance J. 12: Baser, K.H.C Turkish rose oil. Perfum. Flavor. 17(3): Bruneton, J Pharmacognosy, Phytochemistry, Medicinal Plants. Lavoisier Publ. Londres, New York, Paris. p Durst, H.D. and Gokel, G.W Experimental Organic Chem. New York: McGraw Hill Book Company. p Gudin, S Rose: genetics and breeding. Avenue Escadrille Normandie-Niemen, Marseille, Cedex 20, France. Plant-Breeding-Reviews: p.8. Karousou, R., Lanaras, T. and Kokkini, S Essential oils from Rosa centifolia. J. Essential Oil Res. 10: Kokkini, S. and Vokon, D Rosa damascena growing wild in Greece. Econ. Bot. 43: Kokkini, S. and Papageorgion, V.P Constituents of essential oils from Rosa damascena growing wild in Greece. Planta Med. 54: Laenger, R., Mechtler, C. and Jurenitsch, J Composition of the essential oils of commercial samples of Salvia officinalis L. and S. fruticosa Miller: A comparison of oils obtained by extraction and steam distillation. Phytochem. Anal. 7: Lawrence B.M Progress in essential oils: rose oil and extracts. Perfumer & Flavorist 16: Lis, B., Buchbauer, M., Ribisch, G. and Wenger, M.T Comparative antibacterial effects of novel Pelargonium essential oil and solvent extracts. Lett. Appl. Microbiol. 27: Mondello, L., Casilli, A., Tranchida, P.Q., Dugo, P. and Dugo, G Comprehensive two dimensional GC for analysis of citrus essential oils. Flavor Frag. J. 20: Muzika, R.M., Campbell, C.L., Hanover, J.W. and Smith, A.L Comparison of techniques for extracting volatile compounds from conifer needles. J. of Chem. Ecology. 16(9): Robiquest, C Extraction with volatile solvents. J. Pharm. 21: Ruberto, G., Biondi, D. and Renda, A The composition of the volatile oil of Ferulago nodosa obtained by steam distillation and supercritical carbon dioxide extraction. Phytochemi. Anal. 10: Seigler, D.S Plant Secondary Metabolism. Kluwer Academic Publishers. Boston/ Dordrecht/London. p

6 Simandi, B., Deak, A., Ronyai, E., Yanxiang, G., Veress, T., Lemberkovics,E., Then, M., Sasskiss, A. and Vamos-Falusi, Z Supercritical carbon dioxide extraction and fractionation of fennel oil. J. Agric. Food Chem. 47: Stashenko, E., Prada, N.Q. and Martinez, J.R High Resolut. Chromatogr. 19: Steel, R., Torrie, J.H. and Dickey, D Principles and procedures of statistics. A biometrical approach, 3rd ed. McGraw hill publishers, New York. Tuan, D.Q. and Iiangantileke, S.G Liquid CO2 extraction of essential oil from star anise fruits (Illicium verum H.). J. Food Eng. 31: Veriotti, T. and R. Sacks High-speed GC and GC/time of Flight MS of lemon and lime oil samples. Anal. Chem. 73(18): Wang, S Analysis of composition of volatile flower oil of Rosa. Yaubian Uni. Natural Science. 25: Weiss, E.A Rosaceae. p In: E.A. Weiss (ed.), Essential Oil Crops. Oxon, UK: CAB International Wallingford. Wilson, R The Extraction of Essential Oils - Source: A Complete Guide to Understanding and Using Aromatherapy for Vibrant Health & Beauty, ISBN Zoebelein, H Dictionary of Renewable Resources (1997). Weinheim. 490

7 Tables Table 1a. Yield of essential oil of Rosa species through hexane solvent extraction. Species Flower wt used (kg) Concrete oil (g) % of C. oil on petal basis Absolute oil (g) % on the basis of C. oil % of A. oil on petal basis R. centifolia R. damascena R. borboniana R. 'Gruss an Teplitz' Table 1b. Yield of essential oil of Rosa species through hydro distillation. Species Flower wt used (kg) Concrete oil (g) % of C. oil on petal basis Absolute oil (g) % on the basis of C. oil % of A. oil on petal basis R. centifolia R. damascena R. borboniana R. 'Gruss an Teplitz'

8 Table 2. Comparison of percentage composition of the components identified in essential oil of four Rosa species. Component *Solvent Extr. R. damascena R. centifolia R. borboniana R. Gruss an Teplitz **Hydro Distl. Solvent Extr. Hydro Distl. Solvent Extr. Hydro Distl. Solvent Extr. Citronellol Methyl eugenol Geraniol Geranyl acetate Phenylethyl alcohol Linalool Nerol Benzaldehyde Benzyl alcohol Rhodinyl acetate Citronellyl acetate Benzyl acetate Phenylethyl formate *Solvent Extr. = Solvent extraction **Hydro Distl. = Hydro distillation Hydro Distl