CHEMICAL COMPOSITIONS OF ESSENTIAL OIL FROM SIX

CHEMICAL COMPOSITIONS OF ESSENTIAL OIL

FROM SIX LITSEA SPECIES

Sura Illa Binti Mehat

Bachelor of Science with Honours

(Resource Chemistry)

2008

Faculty of Resource Science and Technology

CHEMICAL COMPOSITIONS OF ESSENTIAL OIL

FROM SIX LITSEA SPECIES

SURA ILLA BINTI MEHAT

This project is submitted in partial fulfilment of

the requirements for the degree of Bachelor of Science with Honours

(Resource Chemistry)


UNIVERSITI MALAYSIA SARAWAK

2008

DECLARATION

No portion of the work referred to this project has been submitted in support of an application

for another degree of qualification of this or any other university or institution of higher

learning.

___________________


Resource Chemistry Program


Universiti Malaysia Sarawak

ACKNOWLEDGEMENT

Praise to Allah, finally I am able to finish the Final Year Project. I would like to take

this opportunity to express my appreciation to each individual who had assisting me along the

completion of this project.

First and foremost, I would like thank my respected project supervisor, Assoc. Prof.

Dr. Zaini bin Assim, for his assistance and guidance along the project. His concern and

attention had made the completion of this project possible for me. I would also like to thank

my respected co-supervisor, Assoc. Prof. Dr. Fasihuddin B Ahmad, mentor Dr. Zainab binti

Ngaini, Laboratory Assistants, Mr. Rajuna bin Tahir and Mdm. Zalilawati (Analytical

Chemistry Lab), Mr. Send Takuk (Environmental Lab); Mr. Qammil Muzzammil bin

Abdullah and Mr. Hidir bin Marzuki for species identification; not forgotten Ms. Bebe Norlita

and Ms. Aisyaidil Hanri for their guidance and cooperation through out the project.

My profound gratitude goes to my parents, Mr. Mehat bin Mamat and Mdm. Rogaya

binti Idrus, sisters Sura Nur Azyra and Sura Nur Hidayah for all the love and support; also

Mohd Rizuan bin Isa for the inspiration. For my colleagues in Resource Chemistry Program,

especially Azlan, Eliza, Hafidz, Kollisa, Noraniza, Nur Anisa, Alhafiizh, Irna, Khairunnisa,

Rosilin, Termizi, Zaher, Zainah, Boireh, Nurazrina, Sumiyanti and everybody in Reserve

Officer Training Unit (ROTU) of UNIMAS, your cooperation and understanding is much

appreciated.

Chemical Compositions of Essential Oil from Six Litsea Species


Resource Chemistry Program


Universiti Malaysia Sarawak

ABSTRACT

The percentage, physical properties and anti-termites activity of essential oil from Litsea

resinosa, Litsea nidularis, Litsea rigidularis, Litsea cylindrocarpa, Litsea garciae and Litsea

sp. were studied. The chemical compositions of the essential oil were analyzed using capillary

gas chromatography-flame ionization detector (GC-FID). The percentage of essential oil

obtained from the six Litsea species ranged from 0.05% to 1.40%. The highest amount of oil

was obtained from the leaf of L. cylindrocarpa, while the lowest amount was obtained from

the leaf of L. rigidularis and bark of Litsea sp. The major chemical constituents in L. resinosa

oil are 3-oxo-α-ionol (50.59%), tricosane (43.14%) and acetovanillone (23.49%). The major

chemical constituents in the oil of L. nidularis are acetovanillone (49.68%) and methyl

vanillate (33.40%). The major chemical compositions in L. rigidularis oil are tricosane

(53.97%), methyl vanillate (32.28%), phytol (31.80%) and 6-methoxyeugenol (12.28%). L.

cylindrocarpa oil contained large amount of γ-cadinene (55.39%) and β-guaiene (46.89%).

Ethylfuranone (34.71%) and lauric acid (22.02%) were detected as major components in the

essential oil of L. garciae. The major constituents identified in Litsea sp. oils are lauric acid

(29.81%) and (E,E)-farnesyl acetate (25.78%). Similar compounds detected in five essential

oils from six Litsea species are 4-carbethoxybutyrolactone, lauric acid and ethyl vanillate.

Close relationship were observed between L. resinosa and Litsea sp., also between L.

nidularis and L. rigidularis.

Key words: Litsea species, essential oil, hydrodistillation, Kovat’s Indices

http://www.flavornet.org/info/498-02-2.html






ABSTRAK

Peratusan, sifat fizikal dan aktiviti anti anai-anai minyak pati daripada Litsea resinosa,

Litsea nidularis, Litsea rigidularis, Litsea cylindrocarpa, Litsea garciae dan Litsea sp. telah

dikaji. Komposisi kimia minyak pati telah dianalisis menggunakan kapilari gas kromatografi-

pengesan ion nyalaan (GC-FID). Peratusan minyak pati yang diperolehi daripada enam

spesies Litsea adalah antara 0.05% hingga 1.40%. Amaun minyak tertinggi telah diperolehi

daripada daun L. cylindrocarpa, manakala amaun terendah terdapat pada daun L.

rigidularis dan kulit Litsea sp. Komposisi kimia utama dalam minyak L. resinosa adalah 3-

okso-α-ionol (50.59%), trikosan (43.14%) dan asetovanillon (23.49%). Kandungan kimia

utama dalam minyak L. nidularis adalah asetovanillon (49.68%) dan metil vanillat (33.40%).

Komposisi kimia utama dalam minyak L. rigidularis adalah trikosan (53.97%), metil vanillat

(32.28%), fitol (31.80%) dan 6-metoksieugenol (12.28%). Minyak L. cylindrocarpa

mengandungi jumlah γ-kadinin (55.39%) dan β-guain (46.89%) yang banyak. Etilfuranon

(34.71%) dan asid laurik (22.02%) telah dikesan sebagai komponen utama dalam minyak

pati L. garciae. Kandungan utama dikenalpasti dalam minyak Litsea sp. adalah asid laurik

(29.81%) dan (E,E)-farnesil asetat (25.78%). Sebatian serupa yang dikenalpasti dalam lima

minyak pati daripada enam spesies Litsea adalah 4-karbetoksibutirolakton, asid laurik dan

etil vanillat. Hubungan yang rapat dicerap di antara L. resinosa dan Litsea sp., juga di

antara L. nidularis dan L. rigidularis.

Kata kunci: spesies Litsea, minyak pati, penyulingan hidro, Indeks Kovat’s






TABLE OF CONTENT

ACKNOLEDGEMENT i

ABSTRACT ii

ABSTRAK iii

TABLE OF CONTENT iv-vi

LIST OF TABLES vii

LIST OF FIGURES viii-ix

LIST OF APPENDICES x

CHAPTER ONE INTRODUCTION

1.1 General introduction 1

1.2 Objectives of the project 3

CHAPTER TWO LITERATURE REVIEW

2.1 Litsea species

2.1.1 Morphological description 4

2.1.2 Distribution 5

2.1.3 Uses of Litsea spp. 8

2.2 Chemical compositions of essential oil from Litsea species 9

2.3 Hydrodistillation 10

2.4 Gas chromatography-flame ionization detector (GC-FID) 11

2.5 Cluster analysis 12

CHAPTER THREE MATERIALS AND METHODS

3.1 Samples collection & preparation 13

3.2 Extraction of essential oil 13

3.3 Gas chromatographic analysis 14

3.4 Qualitative analysis 15

3.5 Quantitative analysis

3.5.1 Percentage of essential oil 15

3.5.2 Semi quantitative analysis 16

3.6 Statistical analysis 16

CHAPTER FOUR RESULTS AND DISCUSSIONS

4.1 Abundance of essential oil in Litsea species 17

4.2 Retention times for n-alkanes 18

4.3 Chemical compositions of essential oil

4.3.1 Chemical compositions of essential oil from

L. resinosa

19


L. nidularis

24


L. rigidularis

28


L. cylindrocarpa

32


L. garciae

34


Litsea sp.

36

4.3.7 Organic compounds in essential oil from

the leaf of six Litsea species

39


the bark of five Litsea species

41


the root of three Litsea species

43

4.4 Cluster analysis

4.4.1 Leaf oil of six Litsea species 45

4.4.2 Bark oil of five Litsea species 46

4.4.3 Root oil of three Litsea species 47

4.4.4 Essential oil of six Litsea species 48

CHAPTER FIVE CONCLUSION 49

REFERENCES 51

APPENDICES 54

LIST OF TABLES

Table 2.1

Several Litsea species recorded in Peninsula Malaysia, Sabah and Sarawak 6

Table 4.1

Percentage yield and physical properties of essential oil from Litsea species 17

Table 4.2

Retention times for individual n-alkanes in standard mixture 19

Table 4.3

Chemical compositions of essential oil from L. resinosa 23

Table 4.4

Chemical compositions of essential oil from L. nidularis 27

Table 4.5

Chemical compositions of essential oil from L. rigidularis 31

Table 4.6

Chemical compositions of essential oil from L. cylindrocarpa 34

Table 4.7

Chemical compositions of essential oil from L. garciae 35

Table 4.8

Chemical compositions of essential oil from Litsea sp. 38

Table 4.9

Organic compounds identified in leaf oil from six Litsea species 40

Table 4.10

Organic compounds identified in bark oil from five Litsea species 42

Table 4.11

Organic compounds identified in root oil from three Litsea species 44

LIST OF FIGURES

Figure 4.1

Gas chromatogram of GC-FID for n-alkanes standard 18

Figure 4.2

Gas chromatogram of GC-FID of oil from the leaf of L. resinosa 21

Figure 4.3

Gas chromatogram of GC-FID of oil from the bark of L. resinosa 21

Figure 4.4

Gas chromatogram of GC-FID of oil from the root of L. resinosa 22

Figure 4.5

Gas chromatogram of GC-FID of l oil from the leaf of L. nidularis 25

Figure 4.6

Gas chromatogram of GC-FID of oil from the bark of L. nidularis 26

Figure 4.7

Gas chromatogram of GC-FID of oil from the root of L. nidularis 26

Figure 4.8

Gas chromatogram of GC-FID of oil from the leaf of L. rigidularis 29

Figure 4.9

Gas chromatogram of GC-FID of oil from the bark of L. rigidularis 30

Figure 4.10

Gas chromatogram of GC-FID of oil from the root of L. rigidularis 30

Figure 4.11

Gas chromatogram of GC-FID of oil from the leaf of L. cylindrocarpa 33

Figure 4.12

Gas chromatogram of GC-FID of oil from the bark of L. cylindrocarpa 33

Figure 4.13

Gas chromatogram of GC-FID of oil from the leaf of L. garciae 35

Figure 4.14

Gas chromatogram of GC-FID of oil from the leaf of Litsea sp. 37

Figure 4.15

Gas chromatogram of GC-FID of oil from the bark of Litsea sp. 37

Figure 4.16

Dendrogram of cluster analysis on leaf oil from six Litsea species 45

Figure 4.17

Dendrogram of cluster analysis on bark oil from five Litsea species 46

Figure 4.18

Dendrogram of cluster analysis on root oil from three Litsea species 47

Figure 4.19

Dendrogram of cluster analysis from six Litsea species 48

LIST OF APPENDICES

Appendix 1

Image of the leaf of L. resinosa 54

Appendix 2

Image of the bark of L. resinosa 54

Appendix 3

Image of the root of L. resinosa 54

Appendix 4

Image of the leaf of L. nidularis 55

Appendix 5

Image of the bark of L. nidularis 55

Appendix 6

Image of the root of L. nidularis 55

Appendix 7

Image of the leaf of L. rigidularis 56

Appendix 8

Image of the bark of L. rigidularis 56

Appendix 9

Image of the root of L. rigidularis 56

CHAPTER ONE

INTRODUCTION

1.1 General introduction

Essential oil has been used for centuries as medicine, disinfectant, insect repellant and

fragrances (Brud & Gora, 1989). The existence of man-made fragrances had been proven

since 5000 years B.C. These can be seen from the miniature clay pot used with fragrant oil

and ointment residues, which were identical to those used and found centuries later. They

were found in all parts of the world in China, India, Egypt, Greece and America. Apart from

that, the Neolithic discovery in Toxila dated since 3000 years B.C showed that man was able

to separate the fragrant ingredients from their sources for at least 5000 years (Brud & Gora,

1989).

Over the time, thousands of species have been used to produce flavors and fragrances

via essential oil; foods, drinks and confectioneries; products for personal use such as

perfumes, deodorants, shampoos, bath lotions, toilet soaps, toothpastes and mouth washes;

pharmaceuticals preparations where flavors were added to make the product more appealing

or to mask the taste of less agreeable ones; items used for house, office and industry such as

air fresheners, laundry soaps, detergents, cleaning agents; tobacco and many other products

(Coppen, 1995). Nowadays, scientists prefer to use natural resources to produce these

products instead of using chemicals (Brud & Gora, 1989).

Essential oil also had been used as sources of chemical isolates for derivative

manufacture. Chinese and Brazilian sassafras oil from Cinnamomum camphora and Ocotea

pretiosa, respectively, were both sources of safrole. Safrole was used to produce a flavor and

fragrance compound called heliotropin. C. camphor was also a source of natural camphor.

Rosewood oil, not only favored for perfumery use, but also acts as precursor for other

fragrance compound. Cedarwood oil was the sources of aroma chemicals, while sandalwood

oil gives an aroma that cannot be substituted by the synthetic ones. Eucalyptus oil was used

for perfumery use, as well as raw materials for isolation of cineole and citrinellal (Coppen,

1995).

According to Brud and Gora (1989), essential oil can be used to cure many diseases

and some of them have universal character, such as basil, rosemary, sage, sandalwood and

thyme. Rose oil for example, can be prepared and used to treat fatty dystrophy of liver and

reducing total lipids, cholesterols and triglycerides level in serum. Meanwhile, juniper and

sandalwood oil works well in bladder infections. Essential oil either in the form of ointment,

syrup or pill, can function as remedies for pain, infections, eczema, bronchitis, skin diseases

and many other problems.

The antimicrobial properties of essential oil were also had been studied by Brud &

Gora (1989). Bactericide properties of essential oil can be used for disinfection of air. Some

examples of essential oil that had been studied on Koch bacillus in air were thyme,

peppermint, marjoram and phenol oil. Besides, bactericide activity of essential oil can also be

applied in food conserving. Geranium oil and citronella oil in 0.1% concentration enable the

citrus fruits to be stored for two to three times longer period respectively, and effective

against Penicillum digitatum and P. stabilum.

Essential oil, in the world of insects, can contain very important information and

properties that will affect the insects. It can be used as insects’ attractant as well as repellant.

Zdrawetz that were planted around the rose bushes will prevent lice from attacking the rose

buds. Food vermins such as Tribolum confusum, Rhizopertha domino and Sitophilus granaria

were strongly attracted to laurel, thyme and coriander oil. Thus, the oil was used to lure

insects out from the corn field (Brud & Gora, 1989).

Apart from that, essential oil was also used for agricultural purpose. Basil and mint

were beneficial for the growth of cabbage and marjoram. Certain oil was produced by plants

as toxin against their diseases. Tobacco leaf induced synthesis of sesquiterpenes mixtures, one

of the compound present in essential oil, as an effective toxin against Pseudomonas

solancearum and P. syringee (Brud & Gora, 1989).

Finally, essential oil plays an important role in human psychology. Volatile

components of essential oil act on the human body and mind thus create good feeling, calm or

stimulate arch. Studies show that rose oil for example, not only stimulate nervous system, but

also increased the ability of concentration, accelerate working rate and improve capacity of

work (Brud & Gora, 1989).

1.2 Objectives of the project

The two main objectives of this study are to isolate essential oil from selected Litsea

species using hydrodistillation method, and to characterize the physical and chemical

properties of extracted oil. The other objectives are to analyze chemometrically the

chromatographic data of Litsea essential oils using cluster analysis.

CHAPTER TWO

LITERATURE REVIEW

2.1 Litsea species

2.1.1 Morphological description

Litsea species are evergreen, dioeciously trees. Its leaf is alternate, penninerved, with

naked or scaly buds. Its flower is small, dioeciously, with four to six flowered umbels, sessile

or shortly pedunculate, axillary or in the scars of fallen leaf. It has four to six bracts, which

involucrate. It also has ovoid and campanulate perianth tube that is very short. Apart from

that, it has four or six lobes of limbs, either equal, unequal or in a few wanting (Kirtikar &

Basu, 1993). The flower of Litsea is grouped in little heads, which are themselves put together

to form dense little clusters in the leaf-axils, on the twigs behind the leaf, or on the branch or

trunk (Corner, 1988). For male flower, it has nine or twelve stamens in three-merous, and six

stamens in two-merous flower. The filaments of the first and second rows are usually

eglandular, while those of the third and fourth rows are 2-glandulars, if only they are present.

The anthers are all introrse with four celled. Its ovary is very small, empty or often imperfect.

As for female flower, it has nine or twelve staminodes, or six staminodes in two-merous

flower. Its ovary is free or enclosed in perianth tube, with short or long style. The stigma

usually has irregularly lobes. The fruit or berry is usually resting on the unchanged perianth or

partly elapsed at the base by the often enlarged discoid or cupular perianth tube. Its seed has

thin testa (Kirtikar & Basu, 1993).

2.1.2 Distribution

Litsea species belongs to the family of Lauraceae. According to Corner (1988), there

are about 400 Litsea species throughout the tropics except Africa, with 50 species can be

found in Malaysia. Table 2.1 listed Litsea species recorded in Malaysia. Meanwhile, there are

a few Litsea species can be found in India including L. bourdilloni at the mountains of South

India, L. coriacea, L. floribunda, L. ghatica, L. laevigata, L. mysorensis, L. stocksii, L.

wightiana (Western Ghats), L. deccanensis (Southern Deccan), L. glabrata (South Indian

Hills) and L. glutinosa (India to Australia) (Saldanha, 1984).

Apart from that, L. chinensis can be found throughout the hotter parts of India,

Ceylon, Malay Islands and Australia, L. stocksii (West Peninsula of India), L. polyantha

(along the foot of the Himalayas, up to 3,000 feet to Assam and the Satpura Range,

Coromandel, Malay Peninsula, Java and China) (Kirtikar & Basu, 1993). As for L. cubeba, it

is native to China (occurs naturally in the south of the country, but largely cultivated in central

and eastern China, south of the Yangtze River), Indonesia (grow wild in Java, Sumatra and

Kalimantan), and some other parts of Southeast Asia (Coppen, 1995).

Table 2.1: Several Litsea species recorded in Peninsula Malaysia, Sabah and Sarawak.

Species name Local name Distribution References

L. accedens Atong Bukid,

Buah Talus Dala

Malaysia, Borneo Coode et al. (1996)

L. castanea Medang

(Kelantan Laurel)

Kedah, Perlis, Kelantan Corner (1988)

L. caulifora - Borneo: Sarawak Coode et al. (1996)

L. chewii - Borneo: Sarawak Coode et al. (1996)

L. costalis Medang Keladi

(Elephant Laurel)

In lowland forest and

secondary jungle of Malaysia

Corner (1988)

L. cubeba - Borneo Coode et al. (1996)

L. curtisii Medang,

Engkala Burung

Malaysia Coode et al. (1996)

L. cylindrocarpa Pawas,

Pawas Mowow


L. elliptica

Libas, Medang

Libas,

Medang Pawas


L. firma Medang

(Blue Laurel)

West Malaysia, common in

the forest and secondary

jungle, especially in the south

of the country

Corner (1988)

L. fenestrata - Malaysia, Borneo Coode et al. (1996)

L. ferruginea Medang West & Coasts Malaysia Coode et al. (1996)

L. ficoidea - Borneo: Sabah Coode et al. (1996)

L. fulva - Borneo Coode et al. (1996)

L. garciae Engkala,

Pengolaban (Sabah)

Sabah and Sarawak Coode et al. (1996)

L. gracilipes - Malaysia, Borneo Coode et al. (1996)

L. grandis Medang Daun

Lebar

(Great Laurel)

Peat swamp forest of East &

West Coasts of Peninsula

Malaysia

Ng & Shamsudin (2001)

Species name Local name Distribution References

L. lancifolia

Medang Kikisang

Sabah

Coode et al. (1996)

L. lanceolata - Malaysia, Borneo Coode et al. (1996)

L. machilifolia - Malaysia, Borneo Coode et al. (1996)

L. megacarpa - Borneo Coode et al. (1996)

L. myristicaefolia (Nutmeg Laurel) Peninsula Malaysia,

common in lowland forest,

and in Penang Hill

Corner (1988)

L. ochracea - Borneo Coode et al. (1996)

L. odorifera Medang Pawas Sabah, West & Central

Malaysia

Chandlee (2005)

L. oppositifolia - Borneo Coode et al. (1996)

L. pallidifolia - Borneo Coode et al. (1996)

L. palustris - Borneo: Sarawak Coode et al. (1996)

L. resinosa - Malaysia, Borneo Coode et al. (1996)

L. rubicunda Engkala Burung,

Talus

West & Coasts Malaysia Coode et al. (1996)

L. sessilis Engkala,

Engkala Burung,

Pengalaban Burung,

Talus Dala

Borneo Coode et al. (1996)

L. teysmannii Medang Kelur Peat swamp forest of

Peninsular Malaysia

Ng & Shamsudin (2001)

L. trunciflora - Borneo: Sarawak Coode et al. (1996)

L. turfosa Medang Tabak Borneo Coode et al. (1996)

L. umbellate Medang,

Isop Nanah

(Tumpat)

West Malaysia, common in

lowland jungle and open

country

Corner (1988)

L. varians - Borneo: Sarawak Coode et al. (1996)

2.1.3 Uses of Litsea spp.

Many aromatic substances present in the leaf, stem, bark, root and fruit of certain

species had been investigated and commercially exploited (Hardin et al., 2001). The presence

of aromatic substances in the tissue make the crushed leaf, the cut bark or the fruit smell of

resin, turpentine, citronella, cinnamon, cloves and other such essential oil (Corner, 1988).

For some of the Litsea species that can be found in Malaysia such as L. accedens, it is

used as firewood; the leaf of L. cylindrocarpa is burned to ward of insects, as well as for

medicinal purposes (Coode et al., 1996); while the timber of L. grandis is used for carving

and general utility (Ng and Shamsudin, 2001)

One of the most commercial and internationally traded essential oil of Litsea is L.

cubeba. It is rich in citral, which is about 70 percent, and has an intensely lemon-like, fresh,

sweet odor. It is use for household sprays and fresheners. In China and international market, it

is used as source of citral isolation, for flavor and fragrance purpose or conversion to

derivatives such as ionones and vitamins. Ionones posses a violet-like fragrance. The trunk

wood of L. cubeba can be used to make furniture and handicrafts, although it is not a major

timber species. Meanwhile, other parts of the tree also had been used for medicinal purpose

(Coppen, 1995).

According to Kirtikar and Basu (1993), the root of L. chinensis is bitter and sweetish.

It is useful in aphrodisiac, tonic, biliousness, burning sensations, bronchitis, consumption,

fever, inflammations, overheated brains, pains in the joints, thirst, throat troubles, diseases of

the spleen and paralysis. Its bark is slightly balsamic, best known and most popular as native

drugs. It is used as mild astringent in diarrhea and dysentery. Besides that, it is also used

either dry, or mixed with water or milk, where it is applied on bruises and wounds. The oil

extracted from its berry can be used to treat rheumatism.

The bark of L. polyantha is mildly astringent, and has a balsamic sweetness. Thus it is

used by the hill people to cure diarrhea. As the bark is considered as stimulant, it is applied to

contusions, fresh or dried, and sometimes mixed with milk, to make into a plaster. Powdered

bark is applied to the body for pains due to blows and bruises, and fractures in animal. As for

L. stocksii, its leaf is used in irritation of bladder and urethra, while the oil extracted from the

seed is used to treat sprains and itch (Kirtikar & Basu, 1993).

2.2 Chemical composition of essential oil from Litsea species

The chemical compositions of essential oil from several Litsea species had been

previously analyzed by Ubonnucha et al. (n.d), Fasihuddin et al. (2005) and Aimy (2005).

According to Ubonnucha et al. (n.d), sabinene was detected in L. cubeba; (E)-(-ocimene) in L.

glutinosa; also (E)-cinnamaldehyde and (E)-nerolidol in the leaf and bark of L. petiolata

respectively.

The study conducted by Fasihuddin et al. (2005) has shown that the essential oil

extracted from the leaf of three Litsea species, which are L. resinosa, L. paludosa and L.

gracilipes contained mainly of sesquiterpenoids. The leaf oil of L. resinosa contain large

amount of bulnesol (14.90%), β-caryophyllene (10.20%), β-elemene (10.20%) and other

sesquiterpenoids. Apart from that, the major chemical compounds present in L. gracilipes

were ledene (9.00%) and aromadendrene (8.30%). L. gracilipes also contain high amount of

monoterpenoids, p-menth-1-en-9-ol (1.40%). Finally, the leaf oil of L. paludosa contain

chemical compounds such as elemol (7.70%), γ-cadinene (2.90%), γ-eudesmol (2.80%), selin-

11-en-4α-ol (2.30%), α-cadinene (2.10%), palustrol (1.70%) and selina-3,7(11)-diene

(1.10%).

According to Aimy (2005), α-guaiene, β-selinene, cis-linalool pyran oxide and

methylene bis (methyl sulfide) were detected in L. paludosa, while L. sessilis contain

geranial, ethyl undecanoate and elemicin. Elemicin and geranyl acetone was detected in L.

gracilipes, whereas L. resinosa contains heneicosane and acetovanillone.

2.3 Hydrodistillation

Most essential oil was obtained from plant sample by hydrodistillation/steam

distillation. Essential oil contains substances with boiling point up to 200oC or higher,

including some that were solid at normal temperature. Hydro/steam distillation enables a

compound or mixture of compound to be distilled at a temperature that is below to the boiling

point of the individual constituent. In the presence of steam or boiling water, however, these

substances are volatilized at a temperature close to 100oC at atmospheric temperature. If the

mixture of hot vapor is allowed to pass through a cooling system, it will condense to form two

distinct layers, which comprise of the oil and water layer. The oil will form the top layer,

because mostly (but not necessarily all) the essential oil is lighter than water. The steam that is

used for the distillation is generated either within the vessel that contain the plant material (by

boiling water contained at the base), or by an external boiler. The water is heated either

directly using a fire or by heat exchanger coil. As the method is simple, it is suitable for

small-scale distillation of essential oil (Coppen, 1995).

2.4 Gas chromatography-flame ionization detector (GC-FID)

Gas chromatography (GC) is an analytical method that has been used to solve many

analytical problems. It has been used to separate all classes of compounds. The parameters

used to describe the chromatograms are the retention times and the areas under the

chromatographic peaks. The retention times are used to identify the chemical species that

eluting. The gas flow of GC must be precisely control, while the column used is longer and

narrower. The temperature of the column also must be carefully control for optimize

separations, as the carrier gas does not act as solvent. Flame ionization detector (FID) is one

of the most useful universal detectors. As long as the organic carbon is present in the analyte,

the detector will responds equally according to each unit mass of the analyte. The FID is

insensitive to small molecules such as N2, NOX, H2S, CS2, CO, CO2, COS, HCOOH and H2O.

The FID burns the effluent in a hydrogen/air flame. The separated sample components then

produce cations in the effluent streams. The ions produced are driven by the electric field to

the collector. The higher number of carbon present in the compound means that more

fragments will be produced; thus the detector is more sensitive for that compound. The

current produced due to the ion is amplified, producing the output. When an FID is used,

usually there are carrier gases, hydrogen and compressed gas tank required for the detector

near the GC apparatus (Rubinson and Rubinson, 2000).

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CHEMICAL COMPOSITIONS OF ESSENTIAL OIL FROM SIX