Medicinal and Aromatic Plants—Industrial Profiles


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NIAOULI 239
columns (25m×0.25mm i.d coated with OV-101, film thickness 0.25µm; 25m×0.22mm i.d.
coated with Carbowax 20M, film thickness 0.25µm), using a chromatograph (Shimadzu
GC-14A) equipped with a Shimadzu C-R4A Chromatopac integrator. Detector and injector
temperatures were set at 250°C and 210°C respectively; the oven temperature was
programmed from 50°C–200°C at 5°C per min with nitrogen as a carrier gas. The percentage
composition was obtained from electronic integration measurements using flame ionisation
detection without taking into account relative response factors. Individual oil constituents
were identified from their GC retention times relative to standard compounds.
The first analysis showed a complex chemical composition of the essential oils with 1,8-
cineole constituting a major proportion of the oil. Only 19 chemical compounds were
identified, with a number of unidentified compounds. The compounds which had been
identified were classified into two main groups: “Hydrocarbons” and “Oxygenated Products”.
Acetate and the unknown compounds were classified in an “Other” group. Hydrocarbons
contained two main groups: monoterpenes and sesquiterpenes; while oxygenated products
contained terpenols, sesquiterpenols and ethers (Table 1).
Monoterpenes were the first compounds to be eluted from the gas chromatographic
column. They were more volatile and less polar than the other compounds. This group was
easily identified because of relatively simple molecular structures the ready availability of
standards.
Subsequently sesquiterpenes were eluted. These natural constituents have more complex
structures not as easy to determine as the monoterpene structures. In addition, sesquiterpene
resolution was sometimes inadequate.
Following the sesquiterpenes, oxygenated products were eluted. For the New Caledonian
M. quinquenervia essential oils, this group constituted one or two major chemical
components. However, in this group the tree by tree variation was more significant than in
the hydrocarbon groups.
Detailed Chemical Composition
Typical results are summarised in 
Table 2
.
In addition to the identified constituents, many unknown components were detected.
Numerous peaks appeared in each chromatogram and a large variation in the number of
Table 1 Percentage of each chemical class and group in an essential
oil of M. quinquenervia from New Caledonia
Copyright © 1999 OPA (Overseas Publishers Association) N.V. Published by license under the Harwood Academic Publishers imprint,
part of The Gordon and Breach Publishing Group.

B.TRILLES ET AL.
240
peaks was noted sample by sample. The non-polar phase gave from 18 to 102 GC peaks
whereas the polar CWX 20M phase gave from 45 to 107 peaks.
These variations illustrate the quality and flavour differences in niaouli essential oil.
The clear, colourless to pale yellow oil consists of a complex mixture of compounds. M.
quinquenervia exists in five chemotypes.
1,8-Cineole, Chemotype I
The oxygenated compound, 1,8-cineole, usually constitutes 60–75 per cent of this oil giving
a refreshing and unique flavour. This main constituent is also the important active principle.
The Caledonian Standard recommends at least 60 per cent 1,8-cineole in the oil. As it is
important that commercial oils meet this standard, most niaouli oils in use contain 60 per
cent 1,8-cineole.
The oil’s composition in natural stands of M. quinquenervia can vary considerably from
region to region, locality to locality, place to place even tree to tree throughout the territory
of New Caledonia.
Table 2 Chemical composition (%) of M. quinquenervia (Niaouli) oil from New Caledonia
Copyright © 1999 OPA (Overseas Publishers Association) N.V. Published by license under the Harwood Academic Publishers imprint,
part of The Gordon and Breach Publishing Group.

NIAOULI 241
It appears that 1,8-cineole concentration in New Caledonian M. quinquenervia essential
oils is similar to the mainland Australia cineole chemotype (Brophy et al. 1989; Brophy and
Doran 1996) and higher than 1,8-cineole concentration in Madagascan and Benin oils which
contain 42–60 per cent (Ramanoelina 1992) and 14 per cent (de Souza et al. 1994)
respectively.
Four Other Chemotypes
The steam distilled oils of most M. quinquenervia populations growing in New Caledonia
were found to be largely cineole-rich in character but with varying concentrations. Recent
work at the Laboratoire de Physiologie Végétales Appliquées, one of the research units of
the French University of the Pacific, showed four new chemotypes. The other varieties
which contain constituents in greater concentration than 1,8-cineole are:
(a) Chemotype II, with up to 20 per cent 
γ-terpinene;
(b) Chemotype III, with up to 30 per cent globulol;
(c) Chemotype IV, with up to 30 per cent 
α-terpineol;
(d) Chemotype V, with 10–20 per cent globulol and 10–30 per cent p-cymene.
Niaouli trees were randomly sampled with the viridiflorol chemotype described by
Ramanoelina et al. (1994) not observed in the western area of New Caledonia. Viridiflorol
and nerolidol-rich chemotypes have been reported from Australia (Brophy et al. 1989; Brophy
and Doran 1996). Chemotype I, rich in 1,8-cineole seems very common as it has been
described by Guenther (1950) and other authors.
HYDRODISTILLATION AND HARVESTING
In New Caledonia the resource is not cultivated in plantations. Plants are harvested from
natural areas. Some production problems occur however, when the leaves are not harvested
from selected trees. The first problem is with oil yield. The current yield is about 0.7 per
cent and it is difficult to obtain a yield in excess of this percentage. The second problem is
with the concentration of 1,8-cineole. It is necessary to carry out an analysis of the quality
of the extracted essential oil from each harvest as the cineole concentration may have fallen.
The techniques currently used for extracting essential oils include hydrodistillation, steam
distillation, solvent extraction and liquid CO
2
 extraction. Hydrodistillation is an excellent
method of essential oil extraction as it results in a good yield and recovery of all the essential
oil constituents (Charles and Simon 1990). In New Caledonia hydrodistillation is commonly
used for extracting niaouli essential oil. Harvesting is carried out manually. Samples of
fresh plant material, a mixture of leaves and stems, are used to fill the distillation pot (100
kg fresh weight and 150 litres of water), as shown in 
Figure 1
. The hydrodistillation process
lasts 7 hours. Then the essential oil is packaged in 50ml glass bottles.
The method used in the laboratory was eight hour hydrodistillation of freshly-gathered
leaves in 500ml distilled water with cohobation using all-glass apparatus. The essential oils
were dried over anhydrous sodium sulfate, stored at 4°C until analysis.
Copyright © 1999 OPA (Overseas Publishers Association) N.V. Published by license under the Harwood Academic Publishers imprint,
part of The Gordon and Breach Publishing Group.

B.TRILLES ET AL.
242
Currently using laboratory-scale distillation, M. quinquenervia leaf yields are classified
as follows:
—low oil production: 0–0.5 per cent yield;
—average oil production: 0.5–1.5 per cent yield;
—good oil production: 1.5–2.5 per cent yield;
—excellent oil production: more than 2.5 per cent yield.
The essential oil yield seems to be genetically determined. A current research study of
factors affecting oil yield in various soils is showing that the soil type has no effect on the
yield. Even soils with a high capacity to retain water have little impact on the yield. In a flat
area with impeded drainage, the yield was lower than in a hilly area owing to the water
accumulation which has a direct impact on the water content of the leaves.
A study on the relationship between the climate and the essential oil yield showed that
there was no significant relationship. However, the yield seemed to decrease over two periods,
in August (winter) and in December (high rainfall season). During the other months of the
year the fluctuation observed was close to the average yield. However it was noted that the
main increase in oil yield seems to occur during summer.
Although this suggests that leaf should be harvested in this period, the tendency in New
Caledonia is to harvest throughout the year.
Typical annual production has gradually fallen following the report of Guenther (1950)
in which production was stated as 10–30 tonne per year. The 1984 production estimate was
4 tonne (Lawrence 1985) with current estimates of around 7–10 tonne per year for New
Caledonia sourced oil. About 19 per cent of this is exported to France and marketed overseas
through agents. Today, at current world prices, the annual value of the New Caledonian
niaouli oil production is about 7 million CFP (US$67,000).
Figure 1 The commercial distillation of M. quinquenervia to produce niaouli oil
Copyright © 1999 OPA (Overseas Publishers Association) N.V. Published by license under the Harwood Academic Publishers imprint,
part of The Gordon and Breach Publishing Group.

NIAOULI
243
USES—BIOACTIVITY OF ESSENTIAL OILS OF NIAOULI
Use of Essential Oils
Essential oils are valuable antiseptics with bioactivity against human pathogens. There are
two ways of using the niaouli essential oils:
1.
Traditional medicine,
2.
French Pharmacopoeia regulated preparations.
Use in Traditional Medicine
Essential oils have a high antiseptic capacity. Niaouli oil is mainly used for pulmonary
infections especially for colds and bronchitis. The oil can be absorbed as a tea drink (decoction
by boiling water with dried leaves), or by inhalation (three drops of commercial oil in
steaming water).
Niaouli oil has a high penetration and diffusion capacity which generates efficient
immunisation against latent infections.
On the other hand, according to Degrez (1908), aldehyde-free niaouli oil, called
“Gomenol”, has a cold balsamic flavour. Also, gomenol has low toxicity. On the basis of
gram per kilogram (animal) body weight the reported lethal dose for pure liquid niaouli oil
is 0.17 compared with 0.34 for collargol (colloidal silver), 0.51 for phenol and 0.79 for
formol (formaldehyde) (Degrez 1908). As Gomenol’s lethal dose was 3, niaouli oil with the
aldehydes removed is relatively innocuous.
French Pharmacopoeia
The French Pharmacopoeia lists six products based on Gomenol (essential oil without
aldehydes):
1.
Gomenol (AMM 1943);
2.
Gomenol soluble (AMM 1950);
3.
Gomenol-Syner-Penicilline (AMM 1959);
4.
Gomenoleo (AMM 1943);
5.
Gomenol rectal (AMM 1996);
6.
Gomenol sirop (AMM 1996).
These are listed in the Autorisation de Mise sur le Marché (AMM—equivalent to the USA
Food and Drug Administration Monographs).
Bioactivity of Essential Oils
After the essential oil had been obtained from the hydrodistillation of 100 g of freshly-
gathered leaves in 500ml distilled water for 8 hours, each sample was tested on microorganism
cultures of Erwinia, Candida albicans and Micrococcus. Each sample of oil came from one
tree. The chemical composition was determined before carrying out this antimicrobial
measurement.
Copyright © 1999 OPA (Overseas Publishers Association) N.V. Published by license under the Harwood Academic Publishers imprint,
part of The Gordon and Breach Publishing Group.

B.TRILLES ET AL.
244
A 5mm diameter Whatman circle soaked with essential oil was placed in the centre of a
Petri dish containing medium and microorganism. Assay plates were incubated at 27°C
(±1°C) for four days. The inhibition zones obtained were measured. Table 3, shows significant
but variable bioactivity. Two reference oils, commercial niaouli oil (N) and Gomenol (G),
were used to compare the bioactivity of a host of M. quinquenervia oil samples with
eucalyptus and Australian tea tree oil [Bouraïma-Madjebi et al. 1996].
Two effects were illustrated:
1. a bacteriostatic effect shown by an opaque inhibition zone;
2. a bactericidal effect shown by a translucent inhibition zone.
The Erwinia bacteriostatic and bactericidal effects were higher than for Candida albicans.
For the sample tested on Micrococcus some activities higher than Erwinia bioactivity were
observed. Preliminary tests also showed some biostatic and bactericidal activity of the
Table 3 Zone of inhibition diameters (mm) for essential oil samples of M.
quinquenervia: op: opaque; t: translucent; TTE: Australian Tea Tree oil; N:
commercial essential oils of M. quinquenervia; G: Gomenol (pharmaceutical
product); E: eucalyptus oil; Nia, JLD: samples of essential oil of niaouli tested;
8–63: samples of essential oils of M. quinquenervia
Copyright © 1999 OPA (Overseas Publishers Association) N.V. Published by license under the Harwood Academic Publishers imprint,
part of The Gordon and Breach Publishing Group.

NIAOULI
245
essential oil on Pseudomonas, Klebsiella, Escherichia colt and Agrobacterium. Many of
the New Caledonian M. quinquenervia oils showed bactericidal effects equivalent to or
stronger than eucalyptus and tea tree oil.
REFERENCES
Bernath, J. (1986) Production ecology of secondary plant products. In L.E.Craker and J.E.Simon
(eds.),  Herbs, Spices and Medicinal Plants: Recent Advances in Botany, Horticulture, and
Pharmacology, Vol. 1, Oryx Press, Phoenix, Ariz, pp. 185–234.
Bouraïma-Madjebi, S., Trilles, B., Valet, G. and Pineau, R. (1996) Valorisation des plantes à essence
de Nouvelle-Calédonie. Rapport de convention, No. 239, Productions Vegetates et Forêts/Direction
du Developpement Rural., Université Française du Pacifique, Nouvelle-Caledonie, pp. 5–57.
Brophy, J.J., Boland, D.J and Lassak, E.V. (1989) Leaf Essential Oils of Melaleuca and Leptospermum
species from tropical Australia. In D.J.Boland (ed.), Trees for the Tropics, ACIAR, Canberra, pp.
193–203.
Brophy, J.J. and Doran, J.C. (1996) Essential Oils of Tropical Asteromyrtus, Callistemon and Melaleuca
Species. ACIAR, Canberra, pp. 76–77.
Charles, D.J. and Simon, J.E. (1990) Comparison of extraction methods for the rapid determination of
essential oils content and composition of Basil. J. Amer. Soc. Hort. Sci., 115(3), 458–462.
Dawson, J. (1992) Flore de Nouvelle-Calédonie et Dépendances: Myrtaceae—Leptospermoïdées.
Muséum National d’Histoire Naturelle, Paris, France, p. 251.
Degrez, F. (1908) Toxicité du Gomenol et pouvoir antiseptique comparé. Faculté de Médecine de
Paris.
De Souza, S., Ayedoun, M.A., Batonan, A., Ayss, J. and Akplogan, A.B. (1994) Essai d’aromatherapie
par l’huile essentielle de niaouli du Benin. Revue Med. Pharm. Afr., 8(1), 23–34.
Guenther, E. (1950) The Essential Oils, Van Nostrand, New York, 4, pp. 41–44.
Lawrence, B.M. (1985) A review of the world production of essential oils (1984). Perf and Flav.,
10(5), 2–16.
Ramanoelina, P.A.R. (1992) Etude de la variation de la composition chimique de 1’huile essentielle de
niaouli (Melaleuca viridiflora Sol ex Gaeth) de Madagascar. Thèse de Doctorat des Sciences,
Université d’Aix-Marseille, France, 193pp.
Ramanoelina, P.A.R., Viano, J., Bianchini, J.-P. and Gaydou, E.M. (1994) Occurrence of various
chemotypes in niaouli (Melaleuca quinquenervia) essential oils from Madagascar using multivariate
statistical analysis . J. Agric. Food Chem., 42, 1177–1182.
Copyright © 1999 OPA (Overseas Publishers Association) N.V. Published by license under the Harwood Academic Publishers imprint,
part of The Gordon and Breach Publishing Group.

247
16. POTENTIALLY COMMERCIAL MELALEUCAS
JOSEPH J.BROPHY
School of Chemistry, University of New South Wales, Sydney, Australia
INTRODUCTION
The preceding chapters have discussed the commercial species, M. cajuputi, M.
quinquenervia and M. alternifolia (including the closely related M. linariifolia). Now we
present data on other species which have potential for commercial production.
According to the latest research there are upwards of 230 species within the genus
Melaleuca. Over the last 30 years these have been documented in works by Blake (1968);
Carrick and Chorney (1979); Byrnes (1984, 1985, 1986); Barlow (1986, 1988); Barlow and
Cowley (1988); Cowley et al. (1990); Craven and Barlow (1997), as well as more popular
works by Wrigley and Fagg (1993); and Holliday (1989). Of these approximately 230 species
(Craven 1998), only 3 (M. alternifolia., M. cajuputi and M. quinquenervia) are at present
commonly used for the commercial production of essential oil.
With so many species to choose from it is obvious that during this present century a
significant amount of research has been carried out examining the essential oils of the various
Melaleuca species. This has been carried out both to detail the contents of the various
essential oils and also to search for potentially commercial oils.
Research on the essential oils of members of the genus Melaleuca at the University of
New South Wales has been carried out to both supplement and extend our knowledge of the
chemistry of this genus. We have had the advantage of the availability of specimens collected
for the current revision of the genus by Craven. To date approximately 180 species have
been either examined for the first time or re-examined and the contents of their essential
oils documented. During the course of this work some species have shown essential oils
that may give promise of commercial use. These species, and the oils obtained from them,
are discussed in more detail in this chapter.
The oils were obtained by steam distillation with cohobation in a modified Dean and
Stark apparatus. A full description is given in Brophy and Doran (1996). Analysis of the oils
was by gas chromatography (GC) and combined gas chromatography-mass spectrometry
(GC/MS). Compound identification was, for the most part, by matching of spectra and
retention time of various peaks against authentic pure materials or oils of known composition.
Usual GC conditions are given in Brophy and Doran (1996).
In choosing species to include in this chapter the three main criteria considered were that
the oil, qualitatively, should be interesting and that the oil quantitatively be useful. This
latter criterion meant that the oil yield should, all other things being equal, generally be
greater than 1% based on fresh foliage. One further restriction which has been placed on the
two above criteria is that the species should be a taxonomically defined species. This last
Copyright © 1999 OPA (Overseas Publishers Association) N.V. Published by license under the Harwood Academic Publishers imprint,
part of The Gordon and Breach Publishing Group.

JOSEPH J.BROPHY
248
restriction has at present excluded close to 100 collections from being considered for this
chapter.
As might be expected from so much study of morphological variation, over time there
have been different interpretations placed on the data and different names and associations
proposed. The species referred to in this chapter follow Craven, though reference in the
individual sections is made to previous treatments.
This chapter highlights 15 species of Melaleuca and 1 species from the related genus
Asterornyrtus. The species (M. acadoides, M. alsophila, M. bracteata, M. citrolens, M.
dissitiflora, M. ericifolia, M. leucadendra, M. linophylla, M. quinquenervia, M.
squamophloia, M. stenostachya, M. stipitata, M. trichostachya, M. uncinata, M. viridiflora
and A. symphyocarpa) all met the selection criteria and produce either aromatic oils or
cajuput type (high 1,8-cineole) oils. Asteromyrtus symphyocarpa is included with the
Melaleuca oils because it was once considered a member of the genus Melaleuca before
being placed in the genus Asteromyrtus (Craven 1988) and it produces an essential oil which
is a potential substitute for cajuput oil (Brophy et al. 1994).
Of the 15 species of Melaleuca included in this chapter, 2 are newly named (M. stipitata
and M. squamophloia) and have had only one report of their chemistry (Brophy and Doran
1996). A further species (M.linophylla) has its oil reported on for the first time.
During the course of our recent work on M. leucadendra a much larger number of
specimens have been examined, encompassing the whole of its range across northern
Australia. This has shown that there are two sets of chemical forms of this species. One
chemical form is terpenoid and this form occurs in the western half of its range, extending
from Western Australia to approximately mid Northern Territory. In the eastern half of its
range, from mid Northern Territory to the east coast of Australia, the oil is essentially entirely
aromatic. At the sampling location where both forms were found (Kapalga) there appeared
to be no interbreeding, with the oils obtained being either terpenoid or aromatic but never a
mixture of the two.
There must be considerable doubt about which species is being considered when M.
viridiflora is mentioned in publications prior to 1968. There was confusion between what is
now called M. viridiflora and what is now called M. quinquenervia, two species that overlap
considerably in range and are of similar appearance. Without access to botanical voucher
specimens for these oils it is not possible to say just which species is producing the oil,
though it is thought that the species producing oils rich in nerolidol and/or linalool, especially
coming from New South Wales, is M. quinquenervia.
Basically, M. alsophila, M. dissitiflora, M. stipitata and one chemotype of M. uncinata
produce oils rich in terpinen-4-ol and low in 1,8-cineole. Some of these are lemon scented.
M. bracteata, M. squamophloia, one chemotype of M. leucadendra, and one chemotype of
M. viridiflora produce oils which are aromatic (in either the chemical sense or perfumery
sense) while M. trichostachya, M. acacioides, and some chemotypes of M. citrolens produce
oils which might have perfumery potential. M. linophylla, M. stenostachya, and A.
symphyocarpa all produce oils with similar compositions to cajuput oils.
M. laterifolia subsp. laterifolia, M. pustulata and M. radula all produce oils in yields of
1–2% in which 1,8-cineole accounts for 70–87% of the oil. It should also be mentioned that
both M. alternifolia and M. linariifolia have chemotypes that are characterised by oils rich
in 1,8-cineole. These are usually shunned in favour of the terpinen-4-ol rich oils. M.
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