AU2260900A - Extraction of essential oil from cypress pine - Google Patents

Description

AUSTRALIA

PATENTS ACT 1990

ORIGINAL

COMPLETE SPECIFICATION PETTY PATENT Invention Title: EXTRACTION OF ESSENTIAL OIL FROM CYPRESS

PINE

Name of Applicants: VINCENT JOSEPH COLLINS and MARYANN

COLLINS

a a a a.

The following statement is a full description of this invention, including the best method of performing it known to me/us: EXTRACTION OF ESSENTIAL OIL FROM CYPRESS PINE Field of the Invention The invention relates to methods for producing an essential oil. The oils produced by the methods have been found to contain compounds of commercial worth, and the invention also relates to methods of producing those compounds.

Background of the Invention Essential oils such as that of tee tree are known in the art and preparations containing them find use in perfumery and medicinal applications. Such oils are particularly useful in aroma therapy due to their desirable aromas and in the manufacture of cosmetic or 15 body care products. Essential oils may also have antimicrobial properties as well as wood preservative uses.

In recent years, there has been a trend away from synthetic products toward naturally derived substances.

This has resulted in growth in the demand for essential 20 oils as well as the demand for variety in such oils.

Summary of the Invention The present invention provides a method of producing a blue oil comprising the step of obtaining the oil from a mixture of the bark and wood of Callitris intratropica.

Callitris intratropica is a species of Cypress pine commonly grown in plantations located in warmer climates such as that of the Northern Territory, Australia.

It has been found that by using the bark and wood of Callitris intratropica the oil obtained is coloured blue.

A blue oil is not obtained when oil is obtained from the bark or the wood of Callitris intratropica alone.

H:\MaraR\Keep\Speci\P3158 6 .doc 16/03/00 3 The blue colour of the oil enhances the suitability of the oil for various applications, such as the use of the oil in aroma therapy, or in the manufacture of cosmetics and body care products.

The oil will typically be obtained from the bark and wood by distillation and usually by a hydrodistillation or steam distillation method. Preferably, cohobation will be used during the distillation.

In one embodiment, the oil is obtained from the bark and wood by hydro-distillation or steam distillation, and the miscible components of the oil present in the water collected during the distillation process (the condensate water) are extracted from the condensate water.

Typically, the miscible components of the oil are extracted from the condensate water by solvent extraction using a suitable organic solvent.

Guaiol is found in oil obtained from the wood of species of the genus Callitris. The oil obtained from the wood, or the bark and wood, of Callitris intratropica has 20 a particularly high guaiol content. Guaiol finds use in perfumery compositions for its fixative properties. Guaiol is a precursor of guaiazulene and it is believed the blue colour in the oil produced in accordance with the second or third aspects of the present invention is due to the presence of guaiazulene or a derivative thereof in the oil. Guaiol and guaiazulene are both azulene compounds and more particularly bicyclic sesquiterpenes (Freiser, L.G. and Organic Chemistry, 3rd Ed., pp 915-948, Reinhold Pub. N.Y. 1956.).

The fact that a blue coloured oil is not produced when oil is obtained from the bark or from the wood of Callitris intratropica alone, or when oil is obtained from the wood of other species of the genus Callitris alone, H:\MaraR\Keep\Speci\P31586.doc 16/03/00 4 but is produced when oil is obtained from a mixture including the bark of Callitris intratropica and the wood of one or more species of the genus Callitris, indicates that the bark of Callitris intratropica provides a catalytic component which catalyses the conversion of guaiol to guaiazulene or alternatively, contributes in another way to the conversion such as by altering pH so that the conversion occurs during the oil extraction process.

The rate of formation of the blue colour in the oil has been found to be time-dependent. As will be appreciated, the rate of obtaining the oil from the bark and wood will depend on a number of variables such as whether the bark and wood have been coarsely or finely chipped, whether the bark and wood have been subjected to hammer milling prior to obtaining the oil or whether the bark and wood are tightly or loosely packed during the process of obtaining the oil. Knowing that the development of the colour of the oil is time dependent, 20 the skilled addressee will be readily able to determine the appropriate rate of obtaining the oil from the bark and wood to obtain and maximise the intensity of the colour. Generally, the rate of obtaining the oil from the bark and wood will be comparatively slow.

Once the oil has been produced in accordance with the above defined method, it is possible to analyse the oil by standard techniques, identify the various components in the oil by standard techniques, and isolate some or all of those components by standard techniques.

If desired, guaiol may be isolated from the oil.

If desired, guaiazulene may be isolated from the oil produced in accordance with the present invention.

Guaiazulene is known to be an anti-inflammatory and an H:\MaraR\Keep\Speci\P31586.dOC 16/03/00 5 antiulcerative (The Merck Index, 12 th Edition, Merck Research Laboratories, NJ, 1996, page 776). It has also been suggested that guaiazulene may have antipyretic, anti-allergenic and antibacterial properties.

The guaiol or guaiazulene may be isolated from the oil using standard techniques. Typically, the guaiol or guaiazulene is isolated from the oil by the fractional distillation of the oil.

Brief Description of the Drawings The invention will hereinafter be described with reference to preferred, non-limiting embodiments with o reference to the accompanying drawings wherein: Figure 1 is a schematic view of apparatus suitable for use in obtaining oil from a mixture of bark and wood of species of the genus Callitris; Figure 2 is a gas chromatogram for oil obtained from the bark and wood of Callitris intratropica; and Figure 3 shows the infra-red spectra for guaiol obtained from oil obtained from the bark and wood of Callitris intratropica.

Detailed Description of Preferred Embodiments of the Invention Apparatus used to obtain the oil in a pilot study by steam distillation is shown in Figure 1. The apparatus comprises a 30 kW Lucas LB146 boiler 5 having a maximum pressure capacity of 700 kPa and an 18 mm outlet pipe connected to a manifold 15 comprising a 20 cm length of 2 cm diameter galvanised pipe. A pressure gauge 20 is located at one end of the manifold and a reducing valve set to 60 kPa is located between outlet pipe 10 and manifold 15. As indicated in the figure, charge housing H: \MraR\Keep\Speci\P31586. dC 16/03/00 6 is connected to manifold 15 by 3 m of 12 mm lagged copper piping 35. More particularly, end 40 of lagged piping 35 is secured to coil 45 located between the base and charge chamber 55 of the charge housing 30. Coil 45 is formed from 1 cm diameter copper tubing and is capped with a plurality of evenly spaced holes 60 for passage of steam from boiler 5 into charge chamber 55 in use. The charge housing 30 is further provided with an outlet 65 for the release of waste fluid.

The apparatus also comprises a condenser vessel consisting of a 2 cm diameter galvanised coil 75 having a plurality of turns located in a condenser tank 80 with a water inlet 85 and water outlet 90. Galvanised coil 75 is in communication with a top region 95 of charge chamber through a 0.5 m length of 15 mm diameter copper tubing while an opposite end 100 of coil 75 empties into separation vessel 105.

Separation vessel 105 consists of a tank 110 with a S:'funnel 115 for collecting condensate and having an outlet 120 located in a lower region of the tank. The separation vessel 105 is also provided with a baffle plate 125 for isolating extracted oil from outlet tube 130 for passage of excess water from the separation vessel 105 in use. To avoid escape of extracted oil from tank 110, the entrance 135 of the outlet tube 130 is located below the water level of the tank 110 as shown.

To extract the oil, a 95.5 1 charge of 1 to 2 cm Callitris intratropica bark and wood chip is located in charge chamber 55. Steam at a pressure of 50 to 60 kPa from the boiler 5 is then passed through the charge after release from holes 60 of coil 45. The resulting vapours are collected in galvanised coil 75 where they are caused to condense after cooling as a result of the passage of H:\MaraR\Keep\Speci\P31 586 .doc 16/03/00 7 water through the condenser vessel 70. The rate of water flow is controlled such that the temperature of the condensate is maintained between 85 to 90°C. As shown in Figure 1, the extracted oil separates from water contained in the condensate in separation vessel 105 where it forms a pool 140 for collection.

The intensity of the blue colour of the oil increases significantly after about 3 to 4 hours. The distillation will generally be carried over a period of about 8 hours and more usually about 10 hours or more.

To obtain maximum oil yield, miscible components in the water present in separation tank 110 can be extracted with the use of a suitable organic solvent. The miscible

V

"component of the oil present in the water may also be subjected to cohobation by returning the water from the separation tank 110 to boiler 5 for repassage through charge housing 30. When hydro-distillation is used to obtain the oil, the condensate water may be returned directly to the vessel or chamber containing the bark and o*o 20 wood chips.

The Callitris intratropica oil produced was subjected to analysis by gas chromatography and infra-red spectroscopy. For gas chromatography, a 50 m x 0.22 mm internal diameter column coated with a 0.25 um thick film of 5% phenylmethylsilicone (BP5, S.G.E Australia). To prepare the test sample, 2 mg of the oil was dissolved in 1 ml of n-hexane and a 0.5 pi aliquot introduced to the column via an on-column injector (OCI-3, S.G.E.

Australia). The gas chromatography operating conditions are set out in Table 1.

H:\KlaraR\Keep\Speci\P31586.dOC 16/03/00 8 a a Table 1 Operating Conditions for Gas Chromatography Condition Variable Initial temp: 40 0

C

Initial time: 0 min Final Temp: 2900C Temp. program: 4 0 C min' Final time: 10 min Carrier gas (hydrogen) 40 cm sec-'(approx) flow: Chromatograms were acquired between 10 and 50 minutes using the default set of functional group intervals at a sampling rate of 4 scans per scanset and a resolution of 8 cm The speed of the ZnSe slide used was maintained at a nominal setting of 2. The gas chromatogram obtained for the oil is shown in Figure 2. The peak believed to contain guaiol has a retention time of 32.353 minutes in the column used. The infra-red trace corresponding to that peak is shown in Figure 3.

Analysis by mass spectrometry has revealed that the Callitris intratropica oil produced contains a substantial number of components other than guaiol and guaiazulene.

Some of the components are listed in Table 2.

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S

55 5 S S 9- Table 2 Components of Callitris intratropica oil detected by Mass Spec tromet ry Tricyclene 8- Patchoulene ax-Pinene S- Etemene Myrcene Longifolele 3 -Carene Carayophyllene 0X-Terpinene Thuj opsene para-Cyxnene c-guaiene L imonene Aromadeidrefle cis-Ocimene Humulene Terpinolene y-Selinene para-iso-propenyltolulene 2-Heryl-3-Methyl Maleic Anhydride Fenchol fP-selinene Cainpholenic aldehyde Valencene pinocarveol a-Selinene trans-13-terpineol 8-Guaiene camphor 8-cadinene iso-borneol Elemol pinocainphone Caryophyllene formate Borneol Gi obu lo 1 Terpinen-4-ol Caryophyllene oxide CX-Terpineol Selina-11-en-4-ol Myrtenal Amyris verbenone P3-Eudesmol iso-Bornyl acetate Bulnesol Terpinyl acetate Rimuene X- copaene 5 9

S

H:\MaraR\Keep\Spe~i\P315 86 .dOC 16/03/00 10 Although the present invention has been described hereinbefore with reference to several embodiments, numerous variations and modifications are possible without departing from the scope of the invention which is defined in the following claims.

H:\MaraR\Keep\Speci\P3158 6 .doc 16/03/00

Claims (3)

1. A method of producing a blue oil comprising the step of obtaining the oil from a mixture of the bark and wood of Callitris intratropica.

2. A method according to claim 1, wherein the oil is obtained from the bark and wood by steam distillation.

3. A method according to claim 2, wherein miscible components of the oil present in water condensed during the distillation are extracted from the water by solvent 0: extraction. Dated this 2 4 t h day of March 2000 VINCENT JOSEPH COLLINS and MARYANN COLLINS By their Patent Attorneys GRIFFITH HACK 20 Fellows Institute of Patent and Trade Mark Attorneys of Australia H:\Kar8R\Keep\Speci\P3158 6 .dC 24/03/00