GC-MS Analysis of Phyto-Constituents of the Essential Oil from the Leaves of Melaleuca citrina (Curtis) Dum.Cours

Melaleuca citrina (Curtis) Dum. Cours. commonly known as ‘red bottle brush’, is one of those medicinal plants with great medicinal importance. It is a beautiful evergreen tree belonging to the family Myrtaceae. It is indigenous to Queensland and New South Wales and cultivated throughout India in gardens. The plant is known in folk medicine for its anticough, antibronchitis, insecticidal effects and its volatile oil has been used as antimicrobial and antifungal agents. Moreover, aerial parts of Melaleuca citrina are practiced traditionally in ethnic tribal communities and very little are known about its importance on scientific grounds. The present study conducted to explore the Phyto-Constituents of the essential oil from the leaves of Melaleuca citrina. In the present analysis, the phyto-constituents of the leaves of essential oil of Melaleuca citrina by GC-MS analysis clearly showed the presence of 19 compounds. The results revealed that Eucalyptol (55.14%), Octadien-3-ol, 3,7dimethyl(11.48%), 1,5-Dimethyl-1-vinyl-4-hexenyl butyrate (11.48%), L-.alpha.-Terpineol (16.25%) and .alpha.-Terpineol (16.25%) were reported as 5 major components in the essential oil leaves of the Melaleuca citrina. Eucalyptol is an ingredient in many brands of mouthwash and cough suppressant. Eucalyptol is an effective treatment for nonpurulent rhinosinusitis. Eucalyptol reduces inflammation and pain when applied topically. It kills leukaemia cells. The essential oils from leaves of Melaleuca citrina may serve as potent natural anti-cancer compounds with important roles in human health.

commonly known as 'red bottle brush', is one of those medicinal plants with great medicinal importance. It is a beautiful evergreen tree belonging to the family Myrtaceae. It is indigenous to Queensland and New South Wales and cultivated throughout India in gardens. The plant is known in folk medicine for its anticough, antibronchitis, insecticidal effects and its volatile oil has been used as antimicrobial and antifungal agents. Moreover, aerial parts of Melaleuca citrina are practiced traditionally in ethnic tribal communities and very little are known about its importance on scientific grounds. The present study conducted to explore the Phyto-Constituents of the essential oil from the leaves of Melaleuca citrina. In the present analysis, the phyto-constituents of the leaves of essential oil of Melaleuca citrina by GC-MS analysis clearly showed the presence of 19 compounds. The results revealed that Eucalyptol (55.14%), Octadien-3-ol, 3,7dimethyl-(11.48%), 1,5-Dimethyl-1-vinyl-4-hexenyl butyrate (11.48%), L-.alpha.-Terpineol (16.25%) and .alpha.-Terpineol (16.25%) were reported as 5 major components in the essential oil leaves of the Melaleuca citrina. Eucalyptol is an ingredient in many brands of mouthwash and cough suppressant. Eucalyptol is an effective treatment for nonpurulent rhinosinusitis. Eucalyptol reduces inflammation and pain when applied topically. It kills leukaemia cells. The essential oils from leaves of Melaleuca citrina may serve as potent natural anti-cancer compounds with important roles in human health.

Introduction
Plants have been an important source of medicine for thousands of years. Use of plants for the treatment of many diseases dated back to prehistory and people of all continents have this old tradition. Every culture on earth has relied on the vast variety of natural chemistries' found in plants for their therapeutic properties. Plants are known to produce a variety of compounds to protect themselves against a variety of pathogens. Medicinal plants represent a rich source of antimicrobial agents. Plants are used medicinally in different countries and are a source of many potent and powerful drugs. The medicinal value of plants lies in some chemical substances that produce a definite physiological action on the human body [1].
Plants used for traditional medicine contain a wide range of substances that can be used to treat chronic as well as infectious diseases. A vast knowledge of how to use the plants against different illnesses may be expected to have accumulated in areas where the use of plants is still of great importance [2]. Plant synthesizes a wide variety of chemical compounds, which can be sorted by their chemical class, biosynthetic origin and functional groups into primary and secondary metabolites. Primary metabolites make up the physical integrity of the plant cell and are involved with the primary metabolite process of building and maintaining of living cells [3].
Melaleuca citrina (Curtis) Dum. Cours. commonly known as 'red bottle brush', is one of those medicinal plants with great medicinal importance. The name of the plant, Callistemon, is derived from Greek kalos meaning beautiful and stemon meaning stamens and citrinus from Latin citrinus meaning lemon, referring to the scent of the leaves. It is a beautiful evergreen tree belonging to the family Myrtaceae. It is indigenous to Queensland and New South Wales and cultivated throughout India in gardens.
The plant is commonly named as bottle brush because the cylindrical brush like flowers resembles traditional bottle brush. Different parts of the plant are used by rural people of India. The plant is known in folk medicine for its anticough, antibronchitis, insecticidal effects and its volatile oil has been used as antimicrobial and antifungal agents. Moreover, aerial parts of Melaleuca citrina are practiced traditionally in ethnic tribal communities and very little are known about its importance on scientific grounds.
The leaves of Melaleuca citrina were evergreen, aromatic, alternate, lanceolate with entire margin and anomocytic stomata. Stem was grey in colour. Phytochemical study on leaves reported the presence of flavonoids, alkaloids, terpenoids and steroids. As there is no detailed record of research work available on GC-MS analysis of Phyto-Constituents of the essential oil from the leaves of M.citrina. This is the first report on the chemical composition of essential oil of leaves from this species. The aim of the present study is to analyse the bioactive compounds of the essential oil from the leaves of Melaleuca citrina.

Collection of Plant Materials
The fresh leaves of Melaleuca citrina were collected from the campus of Sri Kaliswari College (Autonomous), Sivakasi. The collected specimens were properly identified with the standard literature and authenticated with valid voucher specimens. The voucher specimens were deposited in the herbarium of Department of Botany, SKC.

Extraction of Essential Oil through Hydro-Distillation Method
The chopped fresh leaves of Melaleuca citrina were subjected into Clevenger type apparatus by using hydrodistillation for about 2-3 hrs. The essential oils were extracted then, the oils were collected separately and dehydrated over anhydrous sodium sulfate and stored in air tight vials at 4°C for further study.

Phytochemical Analysis by GC-MS
GC-MS analysis of extracted essential oils were performed by using a Shimadzu GC-MS QP2010 Ultra model and Gas Chromatograph interfaced to a mass spectrometer (GC-MS) equipped with a Rxi-5Sil MS, fused silica capillary column (30 ml × 0.25 mm ID × 1× df, composed of 100% Dimethyl polysiloxane1,4bis(dimethylsiloxy) phenylene dimethyl polysiloxane). For GC/MS detection, an electron ionization system with an ionizing energy of 70 eV was used. Helium gas (99.999%) was used as the carrier gas at constant flow rate 1 ml/min and an injection volume of 1 µl was employed (Split ratio of 50:1) injector temperature 250°C; ionsource temperature 280°C. The oven temperature was programmed from 100°C (isothermal for 2 min) with an increase of 5°C/min to 200°C, then 10°C/min to 280°C, ending with a 2 min isothermal at 280°C. Mass spectra were taken at 70eV; a scan interval of 0.3 seconds and fragments from 40 to 800 Da total GC running time was 32 minutes and the software adopted to handle mass spectra and chromatograms was a Lab Solutions.

Identification of Phytochemical Components
The identity of the components in the extracts was assigned by the comparison of their retention indices and mass spectra fragmentation patterns with those stored on the computer library and also with published literatures. NIST08s.LIB, WILEY8. LIB library sources were used for matching the identified components from the essential oil.

Results and Discussion
Medicinal plant possesses many bioactive compounds including phenolic and polyphenolic compounds which play key function in detoxification of stress induced by free radicles and exhibit antimicrobial activities [4]. Plants act as important source for all treatments in traditional medical system of the world. The Herbal plants have been used for medical treatment since ancient times [5]. The plants are traditionally used to treat thorn or glass-puncture wounds, abscesses [6], Scrofulosis, carbuncles, dysentery, Rheumatism, isthmus and crural aches, fractures, superficial infections, fingernail inflammation, tumor, difficult labour and pueral pain [7].
The GC-MS analysis of Phyto-Constituents of the essential oil from the leaves of Melaleuca citrina is shown in the table 1. The GC-MS identification of the phytoconstituents was based on comparison of their mass spectra with NIST and WILEY libraries. Structures were defined by percentage similarity values. The identification of the chemical compounds was confirmed based on the peak area, retention time and mass spectrum. In this present analysis, the phyto-constituents of the leaves of essential oil of
[39] Ramasubbu et al., 2020 reported that, there was 30 chemical components was identified from G.imberti and 13 components reported from G. travancorica. Hexahydrofarnesyl acetone was the dominant chemical component of the essential oil of G.imberti followed by Glycodeoxycholic acid, Ambrosin, Hexadecanoic acid and methyl ester. The essential oil of G. travancorica conquered by fatty acids and fatty acid derived compounds such as Geranyl acetone, Farnesyl acetone, Hexahydrofarnesyl acetone and the remaining bioactive compounds were dominated by oxygen-containing di, tri and sesquiterpenoids. The results of antimicrobial effect of essential oils of both species showed strong inhibitory activity even at lowest concentration (10 µl) against 10 human pathogens. These results indicated that, the essential oil of both species is effective and might be applicable in nature medicines and novel drugs.
The current study concludes that the highly active phytoconstituents of Eucalyptol; Octadien-3-ol, 3,7-dimethyl-; 1,5-Dimethyl-1-vinyl-4-hexenyl butyrate; L-.alpha.-Terpineol and .alpha.-Terpineolpresent in the essential oil from leaves of Melaleuca citrina. It may be served as potent natural anti-cancer and anti-microbial compounds with important roles in human health and these compounds might be applicable in nature medicines.