GC-MS characterization of n-hexane soluble compounds of Cyperus rotundus L . rhizomes

Article history: Received on: 24/09/2015 Revised on: 18/10/2015 Accepted on: 30/10/2015 Available online: 27/12/2015 Cyperus rotundus L., popularly known as nutgrass or nagarmotha, is commonly used in the traditional medicine for inflammatory disorders. In the present study, n-hexane extract from rhizomes of C. rotundus (HCR) was analyzed for its constituents using GC-MS technique. The rhizomes were collected, washed, shade dried and powdered. N-hexane extract was prepared by cold percolation method and preliminary phytochemical screening was carried out. It was subjected to Gas Chromatography coupled with Mass Spectroscopy (GC-MS) for the identification of components thereon. Preliminary phytochemical screening of HCR revealed the presence of phenolics, sterols and terpenoids. GC-MS data indicates the presence of twenty seven low polar components in HCR. The major identified molecules include hentriacontane (7.15%), triacontane (6.12%), nonacosane (5%), octacosane (4.38%), octadecane (2.35%), hexadecane (2.32%), eicosane (1.56%), pentatriacontane (1.43%), 9-ditert-butyl-1-oxaspiro(4,5)deca-6,9-diene-2,8-dione (1.37%), Heneicosane, 3-methyl(1.27%), α-cyperone (1.25%), heptadecane (1.15%) and gamma-Sitosterol (1%). As some of these constituents are known to possess anticancer activity, HCR could be used as an active therapeutic ingredient.


INTRODUCTION
Plants harbor several chemical constituents such as phenolics, terpenes, flavonoids and alkaloids, which are known to possess many pharmacological activities (Zheng and Wang, 2001).In recent years, there has been a tremendous interest in the field of natural product research as a source of potential drug substances (Rout et al., 2009).Phytochemicals form the basis of many pharmaceutical formulations used in the treatment of health disorders.Most of the clinical anticancer drugs use phytochemicals as their precursors (Russo et al., 2010).Certain bioactive phytocomponents have been known for their anticancer properties.Some of these include curcumin, genestein, resveratrol, lycopene, rosemarinic acid and sulforaphane (Gutheil et al., 2011).Cyperaceae represents a family of monocotyledonous sedges with grassy resemblance.The ecological significance of Cyperaceae members lie in their riverside vegetation habitat contributing to erosion control and water purification (Babu and Savithramma, 2014).They are known to possess a number of biological activities, including antimicrobial (Bisht et al., 2011), antimutagenic (Kilani et al., 2005), antimalarial (Thebtaranonth et al., 1995), anticonvulsant (Mohsen et al., 2011) and wound healing activities (Puratchikody et al., 2006).C. rotundus L. is a common perennial weed belonging to the family Cyperaceae.The tubers are blackish in color and have a specific odor.C. rotundus typically grows tropical and temperate countries (Jeyasheela et al., 2014).In traditional medicine, the roots and rhizomes of C. rotundus from Asian and African continent are used in the treatment of digestive ailments, dyspepsia, epilepsy, ophthalmia, inflammatory disorders and fever (You et al., 2004).
There are reports on clinical studies with 2 % aqueous extract of C. rotundus wherein the extract showed potent antiinflammatory activity in conjunctivitis (Singh et al., 2012).The plant has been reported to contain alkaloids, saponins, flavonoids, essential oils, glycosides, sesquiterpenes and epoxides (Aslam, 2002).
The rhizome oils of C. rotundus have been shown to possess different compositions.Hitherto, there are no reports on the evaluation of phytoconstituents from n-hexane extracts of this plant.Hence, in this study, composition of n-hexane extracts from rhizomes of C. rotundus (HCR) is reported.

Plant material
Dried rhizomes of C. rotundus were collected from local Ayurvedic pharmacy, Mangalore, India.The plant material was authenticated by Dr. Sunil Kumar, Senior Research officer, Department of Pharmacognosy, SDM Research center, Udyavara, Udupi and Voucher specimen (No.11110101) was deposited.The rhizomes were coarse powdered using a kitchen blender and stored at -20 0 C until further analyses.

Extraction
HCR was prepared according to the procedure explained by Raaman 13 .One gram of powdered sample was extracted with 10 ml of n-hexane by cold percolation for 24 h.

Preliminary phytochemical analysis
Preliminary phytochemical screening was carried out to detect the constituents such as alkaloids, phenolics, coumarins, flavonoids, sterols and terpenoids in the extract by performing qualitative tests (Raman, 2006).

GC-MS Analysis
GC-MS analysis was carried out using Perkin Elmer Turbo Mass Spectrophotometer (GC-MS-5975C, AGILENT, USA) equipped with an auto sampler XLGC.The column used was Perkin Elmer Elite -5 capillary column (dimethyl polysiloxane, 30m × 0.25mm) with a film thickness of 0.25mm.The carrier gas used was Helium at a flow rate of 1.5ml/min.1µl sample injection volume was utilized.The inlet temperature was maintained as 250°C.The oven temperature was programmed initially at 70°C for 3 minutes and then programmed to increase to 300°C at a rate of 10°C.Total run time was 35 minutes.The MS transfer line was maintained at a temperature of 240°C.MS was recorded using electron spray ionization at 70eV and data was evaluated using total ion count (TIC) for compound identification and quantification.The spectra of the components were compared with the spectral database of known components in the GC-MS library (NIST-11).Measurement of peak areas and data processing were carried out by Turbo-Mass-OCPTVS-Demo SPL software (Adams et al., 2004).

CONCLUSION
Even though there are reports on certain major constituents of C. rotundus, the complete phytochemical profile of n-hexane extracts of plant rhizomes is not available till date.Results of the present study indicated the presence of certain pharmacologically important constituents in n-hexane extracts of C. rotundus rhizomes.The identified components can be further isolated and confirmed for their bioactivities.

Table 1 :
Phytochemical screening of n-hexane extract of Cyperus rotundus rhizomes.