herbal plants are valuable gift of nature for mankind and they are the source of a variety of phytochemicals which are utilized for human and animal diets also .
it is capable of synthesizing an overwhelming variety of low molecular weight organic compounds called secondary metabolites , usually with unique and complex structures .
the medicinal actions of plants unique to particular plant species or groups are consistent with the concept that the combination of secondary products in a particular plant is taxonomically distinct .
it states that around 8590% of the world 's population consumes traditional herbal medicines . in recent decades , studies on phytochemical constituents of medicinal plant and
its pharmacological activities have received wide attention [ 36 ] . who has emphasized the need to ensure the quality of medicinal plant products using modern techniques with the application of suitable standards .
many modern methods are adapted for identification and quantification of active principle compounds in plant materials . of them , gas chromatography - mass spectrometry ( gc - ms ) has become firmly established as a key technological platform for secondary metabolite profiling in both plant and nonplant species [ 7 , 8 ] .
the plant species solena amplexicaulis is commonly called creeping cucumber and belongs to the family cucurbitaceae distributed very seldom in the dry deciduous forest and scrub jungles of tamil nadu .
the local healers of tamil nadu and andhra pradesh are prescribing this species for many ailments owing to its effective healing property .
the traditional healers are prescribing the tubers , leaves , and seeds of this species for various ailments like spermatorrhoea , thermogenics , diuretics , haemorrhoids , and invigorating and it is a very good appetizer and cardiotonic .
the whole plant is a potential source of natural antioxidant [ 12 , 13 ] , antidiabetic , and antibacterial agent   also . as the leaves
have good anti - inflammatory activity , it is recommended for inflammation , skin lesions , and skin diseases .
as the reproductive parts like seeds and tubers are exploited severely for medicinal uses , this species becomes rare sighted in its habitats of tamil nadu . despite these wide medicinal uses , no information on qualitative account of phytochemicals is available for this species . to address this lacuna , gc - ms studies were undertaken to explore the phytochemical constituents present in the leaf , stem , and tuber parts of s. amplexicaulis .
the leaf , stem , and tuber parts of s. amplexicaulis were collected separately from the thorny scrub jungles of madukkarai , coimbatore district , tamil nadu , india .
the authenticity of the plant was confirmed in botanical survey of india , southern regional centre , coimbatore , by referring to the deposited specimen ( voucher specimen number : cps 313 ) .
they were washed thoroughly in tap water , shade - dried , and then homogenized to fine powder and stored in air tight bottles .
50  g of powdered leaf , stem , and tuber parts of s. amplexicaulis was separately extracted with 250  ml methanol at the temperature between 60 and 65c for 24  h by using soxhlet extractor .
gc - ms analysis was carried out on a 5975c agilent equipped with a db-5ms agilent fused silica capillary column ( 30  0.25  mm i d ; film thickness : 0.25  m ) , operating in electron impact mode at 70  ev .
pure helium ( 99.999% ) was used as carrier gas at a constant flow of 1  ml / min and an injection volume of 1  l was employed ( split ratio is 10  :  1 ) . mass transfer line and injector temperature were set at 230 and 250c , respectively .
the oven temperature was programmed from 70 ( isothermal for 3  min ) to 300c ( isothermal for 9  min ) at the rate of 10c / min .
total gc running time was 34  min and the ms detection was completed within 35  min . by gc - ms ,
the compounds were separated and then they were eluted from the column and made enter into the detector which was capable of creating an electronic signal .
then the compound entered into the electron ionization ( mass spectroscopy ) detector , where they were bombarded with a stream of electrons causing them to break apart into fragments .
the m / z ( mass / charge ) ratio obtained was calibrated from the graph , called the mass spectrum , and is the fingerprint of the molecule . to identify the compounds ,
the extract was assigned for comparison of their retention indices and mass spectra fragmentation patterns with those stored on the computer library and also with the published literature .
national institute of standards and technology library sources were also used for matching the identified compounds from the plant materials [ 19 , 20 ] .
the gas chromatograms of leaf , stem , and tuber parts of s. amplexicaulis confirmed the presence of various interesting compounds with different retention times as illustrated in figures 1 , 2 , and 3 .
the identified compounds and their retention time , molecular formula , molecular weight , peak area ( % ) , structure , category of the compound , and activities related with medicinal uses are given in tables 1 , 2 , and 3 for leaf , stem , and tuber , respectively .
six compounds were detected in the methanolic leaf extract of s. amplexicaulis . among them , the most prevailing major compounds were phytol , a diterpene ( peak area : 38.24% ) ( figure 4(a ) ) , carane , a terpene ( peak area : 18.76% ) ( figure 4(b ) ) , and 1-octanamine , an aliphatic amine ( peak area : 16.16% ) .
the methanolic stem extract of s. amplexicaulis showed the presence of fifteen different organic compounds .
the major phytochemical compounds among them were 4-(4-ethoxyphenyl ) but-3-en-2-one , an aliphatic acid ( peak area : 56.90% ) ( figure 4(c ) ) , trehalose , sucrose ( peak area : 11.49% ) ( figure 4(d ) ) , hexadecanoic acid , methyl ester , a linoleic acid ester ( peak area : 6.52% ) , and 9-octadecenoic acid ( z)- , methyl ester , another linoleic acid ester ( peak area : 6.76% ) .
9,17-octadecadienal ( z)- , an unsaturated aldehyde ( peak area : 21.77% ) ( figure 4(e ) ) , n - hexadecanoic acid , a palmitic acid ( peak area : 21.75% ) ( figure 4(f ) ) , phthalic acid , di(2-propylpentyl ) ester , a dicarboxylic acid ester ( peak area : 9.48% ) , and 9,12-octadecadienoic acid ( z , z)- , a linolenic acid ( peak area : 9.35% ) were the major phytochemicals on the basis of quantity .
the gas chromatogram shows that the relative concentrations of various compounds are getting eluted as a function of retention time .
the height of the peaks indicates the relative concentrations of the compounds present in the plant .
the mass spectrometer analyzes of the compounds eluted at different times to identify the nature and structure of the compounds . the large compound fragments into small compounds give rise to appearance of peaks at different m / z ratios .
these mass spectra are fingerprint of that compound which can be identified from the data library . generally , the reliability of medicinal plant for its usage is evaluated by correlating the phytochemical compounds with their biological activities . in the present study ,
the gc - ms analysis of the methanolic extracts of leaf , stem , and tuber parts of s. amplexicaulis altogether showed the presence of 35 compounds . in this account ,
the leaf extract contained six compounds among them , phytol ( 38.24% ) is having anticancer , antioxidant , anti - inflammatory , antitumor , antimicrobial , diuretic , and chemopreventive properties and used in vaccine formulations [ 22 , 23 ] .
the other compound , carane ( 18.76% ) is having antifeedant and antioxidant properties [ 24 , 25 ] .
the methanolic stem and tuber extracts showed the presence of greater number of 14 and 15 compounds , respectively .
the six phytoconstituents , namely , undecane , taurolidine , trehalose , hexadecanoic acid methyl ester , 9-octadecenoic acid ( z)- , methyl ester , and benzaldehyde , 2-nitro- , diaminomet hylidenhydrazone in stem extracts have possessed medicinal properties .
undecane , an alkane , is an antimicrobial agent , used as carcinogen [ 27 , 28 ] .
similarly , the other compound , taurolidine , a taurine amino acid derivative , has antimicrobial , antilipopolysaccharidal , and antitumor properties [ 29 , 30 ] .
the linoleic acid esters present in the stem , hexadecanoic acid methyl ester , are reported to have anti - inflammatory , cancer preventive , hepatoprotective , antiarthritic , and anticoronary properties .
the other linoleic acid ester , 9-octadecenoic acid ( z)- , methyl ester , is also having anti - inflammatory , antiandrogenic , and anemiagenic properties . the nitrogen compound , benzaldehyde , 2-nitro- , diaminomet hylidenhydrazone , is known to have the property of curing infectious diseases by its antimicrobial activity . in the tuber extracts ,
the compounds identified , namely , 10,13-octadecadienoic acid methyl ester , trans-13-octadecenoic acid , methyl ester , and 9,12-octadecadienoic acid ( z , z)- , are possessed with anti - inflammatory and cancer preventive characters .
the two compounds , namely , tetradecanoic acid and n - hexadecanoic acid , are antioxidants . the phthalic acid , 1,2-benzenedicarboxylic acid , bis(2-methylpropyl ) ester , is used in the preparation of perfumes and cosmetics . the unsaturated alcoholic compound , 9,17-octadecadienal , ( z)- , is reported to have antimicrobial property .
the study species s. amplexicaulis is endowed with various medicinal properties maybe due to the presence of all these compounds described . in a similar fashion , certain traditional medicinal plant species of cucurbitaceae
have been analyzed phytochemically by using gc - ms and suggested for drug preparation after succeeding in clinical trials [ 34 , 35 ] .
the therapeutic properties of the other compounds in all the three parts of s. amplexicaulis were not yet reported .
our investigation through the present study revealed that the species s. amplexicaulis is a reliable source of bioactive compounds like fatty acid esters , alcohols , hydrocarbons , alkanes , amines , terpenes , and sugars that justify the traditional usage of this species [ 1618 ] by the local healers in coimbatore and tirupur districts of tamil nadu , india , for various ailments .
as gc - ms is the first step towards understanding the nature of active principles [ 36 , 37 ] , further investigation in this species is suggested for the development of novel drugs .
 
 objective . to explore the possible bioactive compounds in the methanolic extracts of leaf , stem , and tuber parts of the medicinal climber , solena amplexicaulis , using gc - ms 
 . methods . 
 gc - ms analysis of the plant extracts were performed by using gc - ms-5975c [ agilent ] and mass spectra of the compounds found in the extract was matched with the data in the library of national institute of standards and technology ( nist ) . 
 results . 
 thirty - five compounds were determined to be present in the parts studied . 
 the active principles with their retention time , molecular formula , molecular weight , peak area , structure , category of the compounds , and activities were predicted . 
 the most prevailing compounds were phytol ( 38.24% ) in leaf , 4-(4-ethoxyphenyl ) but-3-en-2-one ( 56.90% ) in stem , and 9,17-octadecadienal , ( z)- ( 21.77% ) in tuber . 
 conclusion . 
 this study revealed that the species s. amplexicaulis is a good source of many bioactive compounds like terpenes , triazines , esters , alkanes , alcohols , hydrocarbons , aldehydes , amides , and so forth . 
 that justifies the traditional usage of this species . 
1. Introduction
2. Materials and Methods
3. Results
4. Discussion