Volatile Constituents of Matricaria chamomilla

1. Introduction

     Chamomile, Matricaria chamomilla L. Asteraceae family, is a well-known and important medicinal plant in Iran that traditionally have been used for the treatment of various diseases, and it is cultivated all over the world [1, 2]. The medicinal and phar-macological effects of chamomile are mainly connected with its essential oil for its antispasmodic, antimicrobial and disinfective properties [2-4]. Chamomile essential oil is widely used in food, cosmetics and pharmaceutical industries. The largest group of medically important compounds forming the essential oil are α-bisabolol, bisabolol oxides, chamazulene and en-yn-dicycloethers. Flavonoids, coumarins, hydroxycinnamic acids, mucilages and some other primary metabolites also have pharmacological effects [2-5].

     Different essential oil isolation techniques and analysis methods have been applied for studying the volatile constituents of chamomile by several groups [2, 3, 5, 6]. The purpose of this work was to determine the composition of volatile essential oil from a chamomile sample cultivated in Botanical Garden of School of Pharmacy, Isfahan University of Medical Sciences, Isfahan, Iran, to identify and compare the composition of this oil with those of foreign origins.

2. Materials and methods

2.1. Plant material

     Flowers of cultivated M. chamomilla were collected from Botanical Garden of faculty of Pharmacy, Isfahan University of Medical Sciences, Isfahan, Iran in June 2000. The plant identity as Matricaria chamomilla L. was confirmed by the Herbarium Department of School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran. A voucher specimen of the plant was deposited in the herbarium. The air-dried flowers of the plant were powdered and the volatile fraction was isolated by hydrodistillation for 3 h according to the method recommended in British Pharmacopoeia [7]. The oil was dried over anhydrous sodium sulfate and stored in a refrigeratore (4 °C).

2.2. Analysis

      The oil was analyzed by gas chromatography (GC) and GC/ mass spectrometery (MS). GC analysis was carried out on a Perkin-Elmer gas chromatograph Model 8500, equipped with a FID detector and a BP-1 capillary column (30 m×0.25 mm, film thickness 0.25 mm). The operating conditions were as follows: carrier gas, helium with a flow rate of 2 ml/min.; column temperature, 60-275 ºC at 4 ºC/min.; injector and detector temperatures, 275 and 280 ºC, respectively; volume injected, 0.1 ml of the oil; split ratio, 1:25.

      GC/MS analysis was performed on a Hewlett Packard 6890 mass selective detector coupled with a Hewlett Packard 6890 gas chromatograph, equipped with a cross-linked 5% PH ME siloxane HP-5MS capillary column (30 m×0.25 mm, film thickness 0.25 mm) and operating under the same conditions as described above. The MS operating parameters were as follows: ionization potential, 70 eV; ionization current, 1 A; ion source temperature, 200ºC; resolution, 1000.

     Identification of components in the oil was based on GC retention indices relative to n-alkanes and computer matching with the Wiley 275.L library, as well as by comparison of the fragmentation patterns of the mass spectra with those reported in the literature [8-10]. The relative percentage of the oil constituents was calculated from the GC peaks.

3. Results and discussion

      Flowers of M. chamomilla yielded a blue essential oil with a fresh pleasant odour. Sixty-three components were characterized, representing 86.21% of the total oil components detected. These are listed in Table 1 with their percentage composition. The oil was rich in sesquiterpenoids. Many of the unidentified compounds were present in trace amounts. The major constituents of the oil were α-bisabolol oxide A (25.01%), α-bisabolol oxide B (9.43%), spathulenol (8.49%), cis-en-yn-dicycloether (7.42%) and α-bisabolene oxide A (7.17%). Other components were present in amounts less than 7%. M. chamomilla produces a volatile oil which is different from those known chamomile oils [2-6, 11]. This oil is a valuable source of α-bisabolol oxides A and B.

Acknowledgments

      We are grateful to Mrs. A. Jamshidi (Department of Pharmacognosy, Faculty of Pharmacy, Isfahan University of Medical Sciences, Isfahan, Iran) for her technical assistance in the course of practical works.