Chemical Composition of the Essential Oil from Rhizomes of Rhodiola rosea L. Grown in Finland

Journal of Essential Oil Research: JEOR, Nov/Dec 2005 by H�thelyi, �va B, Kor�ny, Korn�l, Galambosi, Bertalan, Domokos, J�nos, P�link�s, J�nos

Abstract

The essential oil of Rhodiola rosea L., from rhizomes cultivated in Finland was analyzed by GC and GC/MS methods in Hungary. The air-dried rhizomes contained 0.04% essential oil. Thirteen components which were characterized in the oil were mainly monoterpenoid (84.3%). Myrtenol (36.9%), trans-pinocarveol (16.1%), geraniol (12.7%) and dihydrocumin alcohol (12.1%) were the most abundant volatiles detected in the oil. Myrtenol, geraniol and linalool were identified as the most important rose-like odor compounds which is important to give a pleasant rose-like scent to these Nordic rhizomes.

Key Word Index

Rhodiola rosea, Crassulaceae, rose root, essential oil composition, octanol, trans-pinocarveol, myrtenol, geraniol, cumin alcohol.

Plant Name

Rhodiola rosea L., (Arctic Root, Rose Root), Crassulaceae family

Source

Seeds of Rhodiola rosea vas collected more than 10 years ago at the border of Norway and north Finland by the staff of S�rk� Nursery (922110 Raahe, Finland). The marketed seedlings were transplanted into the observation plots of Agrifood Research Finland, Mikkeli during 1994. Seedlings from own plants were transplanted into experimental fields in spring 1997.

Plant Part

Rhodiola rosea L. plants have been cultivated at the Agrifood Research Centre in Mikkeli (grid reference: 61� 44' N, 27� 18' E) during 1997-2002 in Finland. It is a perennial plant, reaching a height of 12 to 30 in (max. 70 cm) in cultivation and its full flowering time is in June, having yellow blossoms. The slow growing plants need five years to reach suitable root yields. The plants have a thick rhizome with rose-like fragrance when cut. About 30% of the total fresh weight of the rhizome consists of thinner and hairy root, 15-30 cm in length.

Previous Work

Rhodiola rosea is widely distributed in Arctic and circumpolar areas in high altitudes in mountainous regions throughout Europe and Asia. It is a popular plant in traditional medical systems with a reputation for stimulating the nervous system (1), decreasing depression (2) and preventing high altitude sickness (3). Its Russian name is "golden root," and the plant has been studied intensively in Russia and Scandinavia for more than 35 years (4,5). Its claimed benefits include antidepressant, anticancer, cardioprotective and central nervous system enhancement. The roots have different chemical compounds, of which its pharmacological effects supposed are belonging to phenylpropanoids, like rosavin, rosin, rosarin, and to phenylethanol derivates, like salidroside (6,7).

Roots of R. rosea have been analyzed mainly for the above mentioned compounds (8-10), however little is available concerning the rose-like fragrant compounds of the roots. Recently, terpenes and aroma volatiles have been isolated from the rhizomes of R. rosea of Norwegian origin (11). The dried rhizomes were found to contain 0.05% essential oil with decanol (30.38%), geraniol (12.49%) and p-mentha-1,4-dien-7-ol (5.10%). Geraniol was identified as the most important rose-like odor compound.

Present Work

Whole roots (rhizomes and hairy roots) were dug up on September 21, 2001. The plants were washed, sliced and dried in an air-forced commercial drier at 40�C temperature. The dried rhizomes were ground and water distilled, using a modified Clevenger-type apparatus to produce the oil (in 0.04% yield) at the Technical University Budapest in Hungary.

For identification of the oil components, analytical gas chromatography was performed a Shimadzu GC-14B capillary gas chromatograph apparatus with FID detector and Supelco SE 30 quarz column (25 m x 0.25 mm, 0.25 �m film thickness) at the Szent Istv�n University, Department of Medicinal and Aromatic Plants. Temperature was programmed from 110�-220�C at 8�C/min. Nitrogen was used as carrier gas at a flow rate of 1 mL/min. Injector temperature was 220�C and detector was 250�C.

GC/MS analyses were carried out on a Finnigan Mat GCQ with RESTEC-5 column (30 m x 0.25 mm, 0.32 �m film thickness) at the Naturland Hungary Ltd. Electron impact MS, and the ionization energy was 70 eV, carrier gas was He 75:1 splitter condition. GC/MS analyses were carried out on a Hewlett-Packard 5890/II GC-5971A MSD with Supelcowax 10 column, 60 m x 0.25 mm, 0.32 �m film thickness as well. Ionization energy was 70 eV at the Szent Istv�n University, Department of Food Chemistry.

Tempe rature programming was from 60�-240�C at 4�C/min. Component identifications were made by comparison of their mass spectra and retention indices with those of authentic compounds, and with data in the NIST and NISTPlus Library as described by H�thelyi et al. (12).

As show in Table I, about 99.7% of the oil was identified. The oil was characterized by large amount (84.3%) of monoterpenoid components with myrtenol (36.9%), trans-pinocarveol (16.1%), geraniol (12.7%), cumin alcohol (12.2), linalool (2.7%), dihydrocumin alcohol (2.1%) and perilla alcohol (1.7%). We have identified some other interesting compounds (14.9%) such as: octanol (13.6%) and 6,6-dimethyl-bicyclo-[3,1,1]-hept-2-ene-2-carboxaldehyde (1.0%).