PHYTOCHEMICAL SCREENING AND ESSENTIAL OIL ANALYSIS OF ONE OF THE PERSIAN SEDGES; CYPERUS ROTUNDUS L.

PHYTOCHEMICAL SCREENING AND ESSENTIAL OIL ANALYSIS OF ONE OF THE PERSIAN SEDGES; CYPERUS ROTUNDUS L.

Alireza Ghannadi *¹, Mohammad Rabbani ², Lili Ghaemmaghami ³ and Nahid Malekian ²

Department of Pharmacognosy ¹, Department of Pharmacology ², School of Pharmacy and Pharmaceutical Sciences and Isfahan Pharmaceutical Sciences Research Center, Isfahan University of Medical Sciences ¹, Isfahan 8174673461, Iran

Department of Biology, Faculty of Sciences, Isfahan University ³, Isfahan 8174673441, Iran

ABSTRACT:Phytochemical investigations of tuber extracts and evaluation of the hydro-distilled essential oil, obtained from Cyperus rotundus L. (Cyperaceae Family) growing wild in Isfahan Province (Iran) were studied. Phytochemical surveys revealed the presence of flavonoids, tannins, alkaloids and essential oils. Chemical composition of dried tubers essential oil was also analyzed by GC/MS. Sixty natural compounds consisting 95.8% of the total components were identified from the essential oil obtained with a yield of 0.2% (w/w). Sesquiterpene compounds have been found to occur in largest amount in the oil. Among the oil constituents, cyperene (16.9%), caryophyllene oxide (8.9%), α-longipinane (8.4%) and β-selinene (6.6%) were the major components.

INTRODUCTION: The family Cyperaceaefrom Poales order is one of the numerous families within Iran flora. It comprises about 14 genera in Iran which one of the most important of them is Cyperus. The genus Cyperus L. is distributed throughout the world and has six subgenera and about 45 species in Flora Iranica area ^1-3. It is also called sedges, flat sedges and cypress or nut grass. Cyperus species are used for edible, medicinal and ornamental purposes ^2-5.

Cyperus rotundus L. that is widely distributed in Iran as an invasive known weed has been chosen for phytochemical screening and essential oil analysis. The popular names of the plant in Iran are Ouyarsalam and So'ad. This is a perennial herb with a height of up to 40 cm ^2-4. It has been used in popular and traditional medicines for many centuries in Iran. The plant is mentioned in several Iranian traditional medicine texts like Rhazes’s “al-Hawi”. It has been introduced in Iranian traditional and folk medicine to treat several disorders like some dermatological, gastrointestinal, gynaecological and psychological diseases ^{4, 6}.

Biological and pharmacological studies on this genus revealed antibacterial, antimalarial, antihelmintic, insecticidal, antioxidant, antipyretic, anti-inflammatory, hepatoprotective and antidiabetic activities ^{4, 7-9}.

There are some reports on the phytochemical analysis of species belonging to Cyperus found in the literature. These scientific studies on the species of this genus showed the presence of constituents belonging mainly to the groups of sesquiterpenes, flavonoids, tannins, sterols, alkaloids, benzoquinones and essential oils ^{4, 7-10}. The flavor composition in Cyperus has been studied by various authors ^{7, 8, 10-16}.

The present paper deals with the phytochemical investigations and detailed analysis of the essential oil of dried tubers of C. rotundus from Isfahan Province, Iran by GC-MS. This Cyperus species was not well studied from phytochemical and essential oil analysis point of view in Iran.

MATERIALS AND METHODS:

Plant materials: Tubers of C. rotundus were collected on October 2010 from plants growing wild in Baharan homesteads in Kelishad area in Isfahan Province, Iran at an altitude of ca. 1650 m. The plant specimen was identified by Dr. Lili Ghaemmaghami in Department of Biology, Isfahan University, Isfahan, Iran. A voucher specimen of the plant with number 2262 is deposited in the herbarium of School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran. The dried tubers of the plant (100 g) were chopped in distilled water and its hydro-distilled fraction was isolated by hydrodistillation for 3 h according to the method recommended in British Pharmacopoeia. Essential oil sample was homogenized and dried over anhydrous sodium sulfate and stored in a freezer ^{17, 18}.

Phytochemical screening of different extracts: The different qualitative micro-chemical tests are to be performed for establishing profile of the extracts for its nature of chemical composition. The preliminary phytochemical tests were carried out to detect the presence of steroids, alkaloids, anthraquinones, tannins and phenolic compounds, cardiac glycosides, essential oils, flavonoids and saponins ^17-20.

GC-MS Study: GC/MS analysis was performed on a Hewlett Packard 5972A mass selective detector coupled with a Hewlett Packard 6890 gas chromatograph, equipped with a cross-linked 5% PH ME siloxane HP-5MS capillary column (30m × 0.25 mm, film thickness 0.25 μm).

The GC operating conditions were as follows: carrier gas, helium with a flow rate of  2 mL/min; column temperature, 60^o-275^oC at 4^oC/min; injector and detector temperatures, 280^oC; volume injected, 0.1 μL of the oil; split ratio, 1:25.

The MS operating parameters were as follows: ionization potential, 70 ev; resolution, 1000; ion source temperature, 200^oC.

Identification of components in the oil was based on GC retention indices relative ton-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 ^{18, 19, 21}.  

RESULTS AND DISCUSSION: The extract so obtained from C. rotundus tubers were subjected to preliminary phytochemical screening for detection of natural compounds present in them. The result of phytochemical screening of extracts revealed that flavonoids, tannins, alkaloids and essential oils were present in them.

The essential oil was a yellow liquid bearing the characteristic pungent and aromatic odor of Cyperaceae plants. The essential oil content of the plant was 0.2% (w/w) yield. Sixty compounds were identified, accounting for 95.8% of the oil. The identities of the components of the oil, the retention indices and the percentages are given in Table 1.

The major constituents of the oil were cyperene (16.9%), caryophyllene oxide (8.9%), α-longipinane (8.4%), β-selinene (6.6%), eugenol (4.7%), aristolone (3.5%), β-calacorene (3.3%), α-copaene (3.2%), trans-γ-bisabolene (3.1%) and α-cyperone (3.0%). Other components were present in amounts less than 2.5%. C. rotundus produces an essential oil which is relatively different from those known Cyperus oils. The oil was rich in sesquiterpene hydrocarbones.

Contrary to the earlier reports in Nigeria ^{12, 15} that α-pinene, α-thujene and humulene were present as major compounds in the oil of different species of Cyperus, in the present study these compounds could not be found or just found in trace amounts. In accord with the results of some other studies ^{10, 16, 22}, the most prominent component of our oil, has been found in high amounts in C. scariosus, C. distans and Tunisian C. rotundus essential oils.

TABLE 1: RETENTION TIME (RT), COMPOSITION (%) AND RETENTION INDICES (RI) OF CYPERUS ROTUDUS ESSENTIAL OIL

^aRetention indices on HP-5MS capillary column; ^b%: Calculated from TIC data

Essential oil of Persian C. rotundus is a source of a tricyclic sesquiterpene, cyperene. Caryophyllene oxide, which was found as a second major component of the oil, has been reported in several oils of Cyperaceae family and demonstrated antifungal, anti-inflammatory, anti-carcinogenic and skin enhancing activities ²³. These high content natural compounds are the characteristic components of C. rotundus and can be used as the index for quality controls of the medicines.

In conclusion, the tuber extracts of plant contain flavonoids, tannins, alkaloids and essential oils and the latter contains cyperene, caryophyllene oxide, α-longipinane and β-selinene.  The pharmacological properties of C. rotundus appearto be due to the presence of these active constituents.

ACKNOWLEDGMENTS: This project was financially supported by the vice-chancellery of research at Isfahan University of Medical Sciences and is the result of a part of a Pharm. D. thesis project.

REFERENCES:

1. Mozaffarian V: Plant Systematics- Morphology and Taxonomy. Danesh-e Emrooz Publications, Tehran, 1994: 366-369.
2. Mozaffarian V: A Dictionary of Iranian Plant Names. Farhang-e Mo’aser Publications, Tehran, 1996: 174.
3. Amini Rad M and Sonboli A: Leaf and stem anatomy of the Cyperus subgenus Cyperus in Iran. Rostaniha 2008; 9:6-22.
4. Zargari A: Medicinal Plants. Tehran University Publications, Tehran, Edition 4, Vol. 4, 1990: 679-682.
5. Arafat ShM, Gaafar AM, Basuny AM and Nassef ShL: Chufa tubers (Cyperus esculentus L.)- as a new source of food. World Applied Sciences Journal 2009; 7:151-156.
6. Rhazes MZ: Al-Hawi. Translated by: Afsharypuor S. Publications of Iranian Academy of Medical Sciences, Tehran, Vol. 21, 2005: 16.
7. El-Gohary HMA: Study of essential oils of the tubers of Cyperus rotundus L. and Cyperus alopecuroides Rottb. Bulletin of Faculty of Pharmacy,
   Cairo University 2004; 42:157-164.
8. Lawal OA and Oyedeji AO: Chemical composition of the essential oils of Cyperus rotundus L. from South Africa. Molecules 2009; 14:2909-2917.
9. Nassar MI, Abdel-Razik AF, El-Khrisy ED, Dawidar AM, Bystrom A and Mabry TJ: A benzoquinone and flavonoids from Cyperus alopecuroides. Phytochemistry 2002; 60:385-387.
10. Kilani S, Ledauphine J, Bouhlel I, Ben Sghaier M, Boubaker J, Skandrani I, Mosrati R, Ghedira K, Barillier D and Chekir-Ghedira L: Comparative study of Cyperus rotundus essential oil by a modified GC/MS analysis method- evaluation of its antioxidant, cytotoxic and apoptotic effects. Chemistry and Biodiversity 2008; 5: 729-742.
11. Sonwa MM and Konig WA: Chemical study of the essential oil of Cyperus rotundus. Phytochemistry 2001; 58:799-810.
12. Kubmarawa D, Ogunwande A, Okorie DA, Olawore NO and Kasali AA: Chemical constituents of the volatile oil of Cyperus esculentus L. from Nigeria. Flavour and Fragrance Journal 2005; 20:640-641.
13. Tam CU, Yang FQ, Zhang QW, Guan J and Li SP: Optimization and comparison of three methods for extraction of volatile compounds from Cyperus rotundus evaluated by gas-chromatography-mass spectrometry. Journal of Pharmaceutical and Biomeical Analysis 2007; 44:444-449.
14. Komai K and Tang CSh. Chemical constituents and inhibitory activities of essential oils from Cyperus brevifolius and C. kyllingia. Journal of Chemical Ecology 1989; 15:2171-2176.
15. Ekundayo O, Oderinde R, Ogundeyin M and Stahl-Biskup E: Essential oil constituents of Cyperus tuberosus rottb. Rhizomes. Flavour and Fragrance Journal 1991; 6:261-264.
16. Lawal OA and Oyedeji AO: The composition of the essential oil from Cyperus distans rhizome. Natural Product Communications 2009; 4:1099-1102.
17. Hajhashemi V, Ghannadi A and Moosavi DF: Anti-inflammatory and antinociceptive effects of Salvia hydrangea DC. ex Benth. Research in Medical Sciences 2000; 5, 10-14.
18. Asadipour A, Rezaei Z, Saberi-Amoli S, Amanzadeh Y and Ghannadi A: Volatile constituents of the aerial parts of Cymbopogon olivieri (Boiss.) Bor. from Iran. Journal of Essential Oil-Bearing Plants 2003; 6:51-54.
19. Ghannadi A: Phytochemical investigations on flavonoids and constituents of volatile oil of Stachys lavandulifolia. Journal of Pharmaceutical Sciences 1998; 4: 138-146.
20. Ghannadi A, Ghassemi N, and Sohrabi MJ: Isolation and structural elucidation of Iranian senna flavonoids. Research in Medical Sciences 2000; 5:54-59.
21. Adams RP: Identification of Essential Oil Components by Gas Chromatography/mass Spectrometry. Allured Publishing Co., Carol Stream, 2004.
22. Misra GN, Siddiqui MS and Agarwal SK: Volatile constituents of the essential oil of Cyperus scariosus tubers. Proceedings of the 11^th International Congress of Essential Oils, Fragrances and Flavours- Vol. 4 Chemistry- analysis and structure, New Delhi, 1990: 161-165.
23. Yang D, Michel L, Chaumoni JP and Millet-Clerc J: Use of caryophyllene oxide as an antifungal agent in an in vitro experimental model of onchomycosis. Mycopathologia 1999; 148:79-82.
    

    ---