WO2019123036A1

WO2019123036A1 - Repellent air freshener

Info

Publication number: WO2019123036A1
Application number: PCT/IB2018/058344
Authority: WO
Inventors: Elena STASHENKO; Jairo Rene MARTINEZ MORALES; Diego Camilo DURAN GARCIA; Deisy Corina Bernal Bello
Original assignee: Universidad Industrial De Santander
Priority date: 2017-12-22
Filing date: 2018-10-25
Publication date: 2019-06-27
Also published as: CO2017013334A1

Abstract

The present invention relates to formulations based on mixtures of at least two essential oils selected from the group comprising orange essential oil (Citrus sinensis), ylang-ylang essential oil (Cananga odorata), lemon grass essential oil (Cymbopogon citratus), patchouli essential oil (Pogostemon cablin), eucalyptus essential oil (Eucalyptus sp.), palmarosa essential oil (Cymbopogon martinii), and citronella essential oil (Cymbopogon nardus), dissolved in an alcohol vehicle. Said formulations have insect repellent properties and can be combined in topical compositions or air fresheners.

Description

REPELLENT AIR FRESHENER

FIELD OF THE INVENTION

The present invention relates to formulations from mixtures of at least two essential oils selected from the group comprising orange essential oil (Citrus sinensis), ylang-ylang essential oil {Cananga odoratá), lemongrass essential oil (Cymbopogon citratus) , essential oil of patchouli (Pogostemon cablin), essential oil of eucalyptus (Eucalyptus sp.), essential oil of palmarrosa (Cymbopogon martinii), and essential oil of citronella (Cymbopogon nardus) dissolved in an alcohol vehicle. Said formulations have insect repellent properties and can be combined in topical compositions or air fresheners.

BACKGROUND OF THE INVENTION

For a long time man has known about the beneficial effects that some plants have on the control of pests. Either because plants of certain species were planted together with food crops to ward off pests, until the preparation of extracts of some plants to apply directly to crops.

This is how, for example, tobacco was initially planted on the banks and in the middle of crops to scare away pests, then it was found that tobacco leaves could be chopped and mixed with the soil to control other pests, and finally to boil the tobacco leaves in water to prepare a tobacco water that was applied to the leaves of the plants.

Similarly happened with other species, such as ornamental plants, fruit and aromatic. The houses decorated their gardens with plants such as rue (Ruda graveolens) or calendula, cultivated trees such as orange or lemon and even had in their kitchens small pots with oregano and rosemary.

People noticed that these species reduced the presence of certain pests, for example, flies and / or mosquitoes, in homes and gardens and decided to investigate further to establish the reasons why the pests were moving away.

This is how they found that, in the case of some of these plants, the presence of certain aromas, which may not even be perceptible to the human nose, was undesirable for insects and kept them away. The discovery of these essences gave rise to a series of synthetic products that sought to imitate the effect of these essences, and even enhance it for its cosmetic use. However, as with most synthetic products, although these compounds were very efficient, they also had contraindications, particularly due to the appearance of respiratory diseases, skin allergies and the restriction of their use in the presence of children or pets.

Currently science has chosen to return to natural roots, seeking to isolate and purify the most repellent compounds present in these essential oils to produce cosmetic compositions that are environmentally friendly and safe to use in people of all ages and even for pets.

Although a large number of essential oils with repellent properties have been identified, there is still room for the development of new formulations and synergistic combinations that offer more efficient, longer lasting results and with a greater spectrum. For example, US Pat. No. 5,885,600, which is hereby incorporated by reference in its entirety, teaches a natural insect repellent formulation comprising essential oils obtained from Nim, Citronela and Cedar mixed with an antioxidant, which can be presented in the form of lotions, creams or sprays that can be applied on animals or vegetation or can be used to make various items with insect repellent properties.

For its part, US Pat. No. 5,106,622, which is hereby incorporated in its entirety by way of reference, teaches other insect repellent formulations comprising a mixture of citronella oil, cedar and wintergreen mixed in equal parts on a base of olive oil. The formulation is effective in repelling a wide variety of insects such as mosquitoes, ticks and others.

Likewise, US Pat. No. 5,208,029, incorporated herein in its entirety by way of reference, teaches another insect repellent formulation based on essential oils of plants, which comprises a mixture of essential oil of American pennyroyal, anise and chrysanthemum.

Finally, the patent US 5,306,497, incorporated herein by reference, presents a formulation of essential oils of geranium, balsamhoriza, artemisia, African mint and bergamot, as well as a study on the repellent activity of different compositions of These essential oils.

However, there is still a need for other insect repellent formulations based on natural essential oils that have specific properties or act as more effective repellents. An object of the present invention is to provide a natural formulation of essential oils which is insect repellent and which in turn exhibits a pleasant organoleptic characteristic which environment, perfume, masks or eliminates odors It is also an object of the present invention to provide a composition cosmetic for topical use with insect repellent capacity that is safe to use in children or adults and that does not generate side effects on the health of users.

It is also an object of the present application to provide an air freshening composition for repelling insects and aromatizing environments.

BRIEF DECRIPTION OF THE INVENTION

The repellent and freshening composition of the present application is an alternative to the consumption of repellents of synthetic origin. The essential oils (AE) that make up the blend essential oils were chosen for the formulation of the repellent air freshener, mainly for two reasons. The first, related to the surprising results of the repellent activity obtained for each essential oil individually, in a mixture and in the formulation of the repellent air freshener. In all cases, under the different concentration values evaluated (0.002, 0.02, 0.2 pL / cm ² ), by the area preference test described by Tapondjou et al. [1], always showed a repellent activity similar or greater than the active ingredient ethylbutylacetylaminopropionate (IR3535) at 15%, recognized synthetic compound used in several commercial products with repellent action. The unexpected effect was to obtain a repellent percentage value for the mixture of essential oils diluted in the 5% formulation in the repellent air freshener, higher than the positive control (IRR3535) and equal to the mixture of pure essential oils.

The second reason why essential oils were selected obeys the organoleptic characteristics that these provide to the formulation, as a natural fragrance with its own characteristics, which are described below: it is a fragrance of the citrus floral olfactory family. The output notes are ylang-ylang, neroli and orange; heart notes are fruity jasmine, citrus herbaceous, fresh lemon and rose; the base notes are musk, patchouli, woody, earthy and vetiver.

In one embodiment of the present invention, there is described a formulation comprising a mixture of essential oils selected from the group comprising orange essential oil (Citrus sinensis), ylang-ylang essential oil {Cananga odorata), essential oil of lemongrass (Cymbopogon citratus), essential oil of patchouli (Pogostemon cablin), essential oil of eucalyptus (Eucalyptus sp.), essential oil of palmarrosa (Cymbopogon martinii), and essential oil of citronella (Cymbopogon nardus) dissolved in a vehicle of alcohol.

The essential oils used in the present application are commercially available from multiple manufacturers, so the selection of the most suitable essential oils is made according to the purity thereof. The essential oils employed in the present invention can also be obtained by conventional techniques for extracting essential oils, normally known to the person skilled in the art.

FIGURES

Figure 1: shows the typical chromatographic profile of the mixture of essential oils used in the repellent air freshener formulation, obtained by gas chromatography coupled to mass spectrometry (GC-MS). Column DB-WAX (60 m).

DETAILED DESCRIPTION OF THE INVENTION

For the control of insects different insecticides and synthetic repellents are used; however, its use entails unfavorable effects, such as: water and soil contamination, beneficial insects elimination and toxicity for exposed species and consumers. Additionally, insects have acquired resistance against most synthetic pesticides, which decreases their effectiveness in protection. In addition, an ideal repellent should provide protection against a broad spectrum of arthropods that feed on blood for at least 8 h, which is non-toxic, non-irritating, odorless and non-greasy.

In accordance with the above, the repellent ambient setting composition of natural origin constitutes an alternative for the final responsible consumer, who, at present, has been analyzing the problems involved in the use of synthetic compounds, which is why a repellent mixture It has the characteristic of air freshener, and has a repellent effect equal to or superior to the synthetic compound (IR3535) presents a very good alternative for its use.

Therefore, the present application offers formulations of essential oils of different plants, recognized for their insect repellent and aromatic properties. In one embodiment of the invention, the formulation comprises oils essential oils selected from the group comprising essential oil of orange (Citrus sinensis), essential oil of ylang-ylang {Cananga odoratá), essential oil of lemongrass (Cymbopogon citratus), essential oil of patchouli (Pogostemon cablin), essential oil of eucalyptus (Eucalyptus sp.), palmarrosa essential oil (Cymbopogon martinii), and citronella essential oil (Cymbopogon nardus). The essential oils used in the present application are commercially available from multiple manufacturers, so the selection of the most suitable essential oils is made according to the purity thereof. The essential oils employed in the present invention can also be obtained by conventional techniques for extracting essential oils, normally known to the person skilled in the art.

In a preferred embodiment of the invention there is provided a formulation comprising two or more of the essential oils selected from the group comprising orange essential oil (Citrus sinensis), ylang-ylang essential oil (Cananga odoratá), lemongrass essential oil ( Cymbopogon citratus), essential oil of patchouli (Pogostemon cablin), essential oil of eucalyptus (Eucalyptus sp.), Essential oil of palmarrosa (Cymbopogon martinii), and essential oil of citronella (Cymbopogon nardus) dissolved in a suitable vehicle.

In a preferred embodiment of the invention there is provided a formulation comprising three or more of the essential oils selected from the group comprising orange essential oil (Citrus sinensis), ylang-ylang essential oil (Cananga odoratá), lemongrass essential oil ( Cymbopogon citratus), essential oil of patchouli (Pogostemon cablin), essential oil of eucalyptus (Eucalyptus sp.), Essential oil of palmarrosa (Cymbopogon martinii), and essential oil of citronella (Cymbopogon nardus) dissolved in a suitable vehicle. In a preferred embodiment of the present invention, the vehicle is an alcohol.

In a still more preferred embodiment of the invention there is provided a formulation comprising four or more of the essential oils selected from the group comprising orange essential oil (Citrus sinensis), ylang-ylang essential oil (Cananga odoratá), essential oil of lemongrass (Cymbopogon citratus), patchouli essential oil (Pogostemon cablin), eucalyptus essential oil (Eucalyptus sp.), palmarrosa essential oil (Cymbopogon martinii), and citronella essential oil (Cymbopogon nardus) dissolved in a suitable vehicle and the vehicle is ethanol. In a further embodiment according to the present invention, the composition of the formulation comprises: Table 1. Repellent air freshener formulation ingredients.

AE: essential oil

A larger amount of orange AE base is added, because this oil provides the base of the fragrance, which is part of the citrus floral olfactory family. The oxygenated compounds present in the orange EA provide this olfactory characteristic. The oxygenated compounds of the orange EA are in a low concentration and therefore it is necessary to add a larger amount of base, which maintains the characteristic citric note.

The formulations according to the present invention are made by adding the amounts in a container at room temperature and stirring vigorously for 10 minutes.

EXAMPLE 1

Air freshener comprising a repellent formulation

It produces a mixture of essential oils of orange (Citrus sinensis), ylang-ylang {Cananga odoratá), lemongrass (Cymbopogon citratus), patchouli (Pogostemon cablin), eucalyptus (Eucalyptus sp.), Palmarrosa (Cymbopogon martinii), citronella (Cymbopogon) nardus) in an ethanol vehicle, according to the following composition:

EXAMPLE 2

Comparison of the repellent activity of the individual essential oils and the compositions according to the present invention.

Table 2 shows the results of the repellent activity of the individual essential oils, in formulation without and with the ethanol vehicle, according to Example 1, against Tribolium castaneum, which was evaluated using the area test of preference described by Tapondjou et al. [one ]. The essential oils and the formulation were dissolved in acetone and the solutions arranged in the corresponding section of the filter paper, applying equal volumes to generate concentrations of 0.00002, 0.0002, 0.002, 0.02 and 0.2 pL / cm ² . As a positive control, a commercial repellent formulation of synthetic origin (Stayofí ®) was used, which contains 15% ethylbutylacetylaminopropionate (IR3535) as an active ingredient.

The percentage of repellency (PR) for the 2 and 4 hours of exposure was calculated using the following formula: PR = [(Nc - Nt) / (Nc + Nt)] x100, where Nc and Nt are the number of insects in the control areas (acetone) and treated, respectively. Each concentration of essential oil was evaluated in triplicate and the experiments were repeated three times, on different days.

Table 2. Percentages of repellency obtained from essential oils, repellent ambient setting formulation and commercial repellent (IR3535) against Tribolium castaneum, at different exposure and concentration times.

EXAMPLE 3

Chemical characterization of repellent compositions

Table 3 shows the chemical composition of the volatile fraction of the repellent air freshener mixture, obtained by SPME solid phase microextraction, using fibers of different polarity and characterized by gas chromatography coupled to mass spectrometry (GC-MS), using polar pole DB-WAX (60 m).

The SPME fiber was exposed for 20 minutes at 60 ° C, to steam of 5 mg of the repellent air freshener mixture in a 15 mL amber vial, preheated for 10 minutes, at the extraction temperature. The desorption of the compounds was carried out directly at the injection port (250 ° C) of the gas chromatograph. The cleaning of the fiber was carried out according to the manufacturer's recommendations. The chromatographic separation was carried out in an AT 6890N gas chromatograph (Palo Alto, CA, USA), coupled to an Agilent Technologies MSD 5975 Inert XL selective mass detector, with DB-WAX capillary column (60 mx 0.25 mm, Dl x 0.25 miti, df). Helium (99.995%, AP gas, Linde, Bogotá, Colombia), 16.47 psi of pressure at the inlet of the column, and 1 mL / min of volumetric flow velocity were used as the trawl gas.

The injection port was maintained at 250 ° C, with Split injection mode (ratio 30: 1). The identification of the compounds was made by comparing the linear retention indexes (LRI), calculated by taking into account the retention time of a mixture of linear hydrocarbons (C5-C25), in addition to comparing the experimental mass spectra with the available databases (Adams 2004, NIST 2007 and Wiley 2008) and the use of certified reference substances. Table 3. Chemical composition of the volatile fraction of the repellent air freshener formulation extracted with fibers of different polarity using SPME.

Relative amount,%. Average ± S (n = 3)

Compound IRL EXP _

CAR / PDMS PDMS / DVB PDMS

Ethanol 915 6.2 ± 0.5 9.0 ± 1.6, 4.0 ± 0.2 a-Pinose 1024 0.9 ± 0.06 0.8 ± 0.2 2.1 ± 0.4 b- Pineno 1 128 - 0,1 ± 0,1 Mircene 1138 0.7 ± 0.03 0.6 ± 0.4 0.5 ± 0.1

Limonene 1205 22.0 ± 2.8 17.2 ± 4.8 14.4 ± 3.0

Eucalyptol 1216 2.0 ± 0.1 2.9 ± 1.1 4.8 ± 1.3 frans-p-Ocimeno 1249 0.1 ± 0.1 g-Terpinene 1245 - 0.2 ± 0.1

p-Cimeno 1268 - 0.2 ± 0.1

p-Methyl-anisole 1436 2.0 ± 0.1 0.6 ± 0.2 0.8 ± 0.2

Citronelal 1478 0.8 ± 0.1 1.2 ± 0.3 0.8 ± 0.4 p-Patchoulene 1501 1.4 ± 0.2 1.5 ± 0.4 0.9 ± 0.3

Linalool 1541 1.0 ± 0.2 1.8 ± 0.6 2.5 ± 0.9 a-Gurjunene 1548 - 0.3 ± 0.1 0.3 ± 0.2 p-Elemeno 1589 0.5 ± 0, 2 a-Guaieno 1604 - 12.3 ± 1.7 7.3 ± 1.2

Caryophyllene 1621 - 3.1 ± 0.7 2.3 ± 0.4 a-Guaieo 1648 10.4 ± 0.6

Methyl benzoate 1625 4.0 ± 0.4 0.9 ± 0.4 0.8 ± 0.4

Aromadendrene 1623 1.6 ± 0.1 0.7 ± 0.1 1.0 ± 0.1

Seychelene 1669 3.2 ± 0.6 6.1 ± 1.2 3.7 ± 0.6

Neral 1686 2.7 ± 0.5 4.2 ± 0.8 2.6 ± 0.7 a-Humulene 1690 - 0.6 ± 0.1 0.5 ± 0.4 a-Terpineol 1701 0.6 ± 0, 1 0.8 ± 1.3 0.5 ± 0.1

Viridifloreno 1710 0.4 ± 0.1

Germacreno-D 1725 4.9 ± 0.6 a-Bulneseno 1731 8.2 ± 5.1 11.1 ± 1.6

Benzyl Acetate 1728 4.4 ± 0.1 8.8 ± 4.0

a-Farnesene 1748 0.8 ± 0.2

Citral 1735 19.3 ± 2.3

d-Guaieno 1744 8.1 ± 0.6

Citronelol 1757 0.3 ± 0.1

Geranyl acetate 1754 2.4 ± 0.6 3.6 ± 0.8 d-Cadinne 1767 0.2 ± 0.1 0.3 ± 0.1 g-Cadinen 1772 0.10 ± 0.05

E-Anethole 1824 0.11 ± 0.01

Geraniol 1839 1.6 ± 0.4 1.2 ± 0.6 5.5 ± 0.9

Nerol 1780 0.4 ± 0.1

Caryophyllene oxide 2001 0.14 ± 0.02

Globulol 2085 0.2 ± 0.1 0.4 ± 0.2

Cinnamyl Acetate 2139 0.5 ± 0.4 0.5 ± 0.1 0.8 ± 0.3

Timol 2181 0.3 ± 0.1 0.3 ± 0.2

Patchoulol 2211 2.8 ± 0.4 4.3 ± 0.9 3.9 ± 1.7

Pogostol 2226 0.2 ± 0.1 0.2 ± 0.1

(Z, Z) -Farnesol 2344 0.2 ± 0.1

Benzyl Benzoate 2630 0.5 ± 0.4 1.3 ± 0.6

EXAMPLE 4

Chromatographic analysis of the composition of the mixture of essential oils Table 4 shows the chemical characterization of the formulation of Example 1, by gas chromatography coupled to mass spectrometry (GC-MS), using DB-5MS 60 m column, of the mixture of essential oils used for the formulation repellent air freshener.

Table 4. Chemical composition of the mixture of essential oils used in the formulation of the repellent air freshener.

DB-WAX

Pico ^Com P ^uesto Relative amount,%

IRL LIT

1 Limonene 1 198 7.1

2 1, 8-Cineol 1206 0.3

3 Citronelal 1476 2.7

4 Unidentified 0.4

5 Linalol 1544 4.8

6 a-Guaieno 1612 10.3

7 Cariofileno 1598 2.3

8 Methyl benzoate 1615 0.8

9 Unidentified 0.4

10 Neral 1654 6.3

1 1 Terpineol 1694 0.5

12 Aromadendreno 1620 1 .9

13 Terpinyl Acetate 1695 0.6

14 Benzyl acetate 1723 4.8

15 a-Bulneseno 1730 7.4

16 Geranial 1733 12.9

17 Geranyl acetate 1752 3.1

18 Citronelol 1763 1, 3

19 Nerol 1795 0.5

20 Geraniol 1839 10.8

21 Globulol 2082 0.8

22 Cinnamon Acetate 2145 0.8

23 Patchoulol 2218 1 1 .9

24 Pogostol 2240 0.8

25 Farnesol 2324 0.5

26 Benzyl Benzoate 2612 1, 8 Figure 1 shows the chromatographic profile obtained from the mixture of essential oils used in the repellent air freshener formulation.

The data from the previous tables show that surprising results were achieved for the mixture of essential oils diluted in the repellent air freshener formulation. Even at a lower evaluated concentration, the mixture of essential oils presented a repellency value higher than the positive control (IRR3535) and equal to the mixture of pure essential oils. This shows a synergistic effect of the mixture of essential oils.

Additionally, the repellency results at 2 and 4 hours of exposure of the individual essential oils, the mixture of these and the mixture included at 5% in the formulation of the repellent air freshener, did not show significant differences. This result is very good, since the effect of the components present in the mixture lasts over time. A higher repellency result than the reference compound IRR3535 was achieved, which is related to the high contents and synergic effect of the components identified in the mixture of essential oils with repellent properties.

The relationships found between the chemical composition of the mixture of essential oils used in the formulation of the repellent air freshener and the percentage of repellency, is related to the high content of oxygenated compounds, such as neral, geranial, geraniol, citronellal, 1, 8- cineol, among others. These results are consistent with that reported by other authors [2], who found that compounds such as eugenol, carvone, citral, terpineol, citronellol, citronellal, camphor and thymol had high repellency values against insects of the order Diptera, compared with their hydrocarbon analogues . Studies carried out by Enan [3], showed that eugenol mimics octopamine, an important neurotransmitter in insects, causing an increase in intracellular calcium levels in the cloning of Periplaneta americana brain cells.

The mechanism of action of repellency in arthropods is not clear, and there is a conflict in the existing evidence in the literature. However, it is reported that the repellents act with the olfactory receptors of mosquitoes, blocking the smell sensation [4] Another study in the species T. Castaneum [5], showed that when the hydrocarbon chain of terpenes and sesquiterpenes is introduced the group hydroxyl in the tertiary position, the repellency percentage and its toxicity are increased. This effect is related to the penetration capacity of the hydrocarbon chain on the lipophilic cuticle of the insects and their subsequent repellent effect on the OH group. This effect was also evidenced for the germacrol, whose repellent activity was greater than its hydrocarbon analogue, germacrene. The repellent mix of the repellent air freshener includes a high content of a-guaiene, patchulol and trans-caryophyllene, compounds that contribute to the repellent effect of the air freshener, in addition to participating as fixators in the formulation.

Although up to now a description has been made of some of the preferred embodiments of the invention, they are not limiting and the person skilled in the art will understand that modifications and variations are possible without departing from the spirit of the invention.

Claims

1. A formulation of essential oils with insect repellent properties, characterized in that it comprises a combination of essential oils taken from orange (Citrus sinensis), ylang-ylang essential oil {Cananga odoratá), lemongrass essential oil (Cymbopogon citratus), oil essential of patchouli (Pogostemon cablin), essential oil of eucalyptus (Eucalyptus sp.), essential oil of palmarrosa (Cymbopogon martinii), and essential oil of citronella (Cymbopogon nardus), dissolved in an ethanol or alcohol in the following proportions:

80 - 95% by weight of Ethanol or Alcohol

0.5 - 5% by weight of essential oil of Citrus sinensis

0.1 - 5% by weight of Cananga odorata essential oil

0.1 - 5% by weight of essential oil of Cymbopogon citratus

0.1 - 5% by weight essential oil of Pogostemon cablin

0.1 - 5% by weight of essential oil of Eucalyptus sp

0.1 - 5% by weight of essential oil of Cymbopogon martinii

0.1 - 5% by weight of essential oil of Cymbopogon nardus where the chromatographic analysis of the composition of the mixture of essential oils has a chemical composition as follows:

DB-WAX

Compound Relative amount,%

Pico IRL LIT

1 Limonene 1 198 7.1

2 1, 8-Cineol 1206 0.3

3 Citronelal 1476 2.7

4 Unidentified 0.4

5 Linalol 1544 4.8

6 a-Guaieno 1612 10.3

7 Cariofileno 1598 2.3

8 Methyl benzoate 1615 0.8

9 Unidentified 0.4

10 Neral 1654 6.3

1 1 Terpineol 1694 0.5

12 Aromadendreno 1620 1 .9 13 Terpinyl Acetate 1695 0.6

14 Benzyl acetate 1723 4.8

15 a-Bulneseno 1730 7.4

16 Geranial 1733 12.9

17 Geranyl Acetate 1752 3.1

18 Citronelol 1763 1.3

19 Nerol 1795 0.5

20 Geraniol 1839 10.8

21 Globulol 2082 0.8

22 Cinnamon Acetate 2145 0.8

23 Patchoulol 2218 11.9

24 Pogostol 2240 0.8

25 Farnesol 2324 0.5

Benzyl Benzoate 2612 1.8 and where the chemical composition of the volatile fraction of the formulation extracted with fibers of different polarity by SPME is:

Relative amount,%. Average ± S (n = 3)

Composite IRL EXP _{CAR / PDM} S PDMS / DVB PDMS

Ethanol 915 6.2 ± 0.5 9.0 ± 1.6 4.0 ± 0.2

a-Pineno 1024 0.9 ± 0.06 0.8 ± 0.2 2.1 ± 0.4

b-Pineno 1128 0.1 ± 0.1

Mircene 1138 0.7 ± 0.03 0.6 ± 0.4 0.5 ± 0.1

Limonene 1205 22.0 ± 2.8 17.2 ± 4.8 14.4 ± 3.0

Eucalyptol 1216 2.0 ± 0.1 2.9 ± 1.1 4.8 ± 1.3

frans-p-Ocimeno 1249 0.1 ± 0.1 g-Terpinene 1245 0.2 ± 0.1

p-CImeno 1268 0.2 ± 0.1

p-Methyl-anisole 1436 2.0 ± 0.1 0.6 ± 0.2 0.8 ± 0.2

Citronelal 1478 0.8 ± 0.1 1.2 ± 0.3 0.8 ± 0.4

b-Patchoulene 1501 1.4 ± 0.2 1.5 ± 0.4 0.9 ± 0.3

Linalool 1541 1.0 ± 0.2 1.8 ± 0.6 2.5 ± 0.9

a-Gurjunene 1548 0.3 ± 0.1 0.3 ± 0.2

b-Elemeno 1589 0.5 ± 0.2

a-Guaieno 1604 12.3 ± 1.7 7.3 ± 1.2

Caryophyllene 1621 3.1 ± 0.7 2.3 ± 0.4

a-Guaieno 1648 10.4 ± 0.6

Methyl benzoate 1625 4.0 ± 0.4 0.9 ± 0.4 0.8 ± 0.4

Aromadendrene 1623 1.6 ± 0.1 0.7 ± 0.1 1.0 ± 0.1 Seychelene 1669 3.2 ± 0.6 6.1 ± 1.2 3.7 ± 0.6

Neral 1686 2.7 ± 0.5 4.2 ± 0.8 2.6 ± 0.7

a-Humuleno 1690 0.6 ± 0.1 0.5 ± 0.4

a-Terpineol 1701 0.6 ± 0.1 0.8 ± 1.3 0.5 ± 0.1

Viridifloreno 1710 0.4 ± 0.1

Germacreno-D 1725 4.9 ± 0.6

a-Bulneseno 1731 8.2 ± 5.1 11.1 ± 1.6

Benzyl Acetate 1728 4.4 ± 0.1 8.8 ± 4.0

a-Farnesene 1748 0.8 ± 0.2

Citral 1735 19.3 ± 2.3

d-Guaieno 1744 8.1 ± 0.6

Citronelol 1757 0.3 ± 0.1

Geranyl acetate 1754 2.4 ± 0.6 3.6 ± 0.8

d-Cadinne 1767 0.2 ± 0.1 0.3 ± 0.1

g-Cadinen 1772 0.10 ± 0.05

E-Anethole 1824 0.11 ± 0.01

Geraniol 1839 1.6 ± 0.4 1.2 ± 0.6 5.5 ± 0.9

Nerol 1780 0.4 ± 0.1

Caryophyllene oxide 2001 0.14 ± 0.02

Globulol 2085 0.2 ± 0.1 0.4 ± 0.2

Cinnamyl Acetate 2139 0.5 ± 0.4 0.5 ± 0.1 0.8 ± 0.3

Timol 2181 0.3 ± 0.1 0.3 ± 0.2

Patchoulol 2211 2.8 ± 0.4 4.3 ± 0.9 3.9 ± 1.7

Pogostol 2226 0.2 ± 0.1 0.2 ± 0.1

(Z, Z) -Farnesol 2344 0.2 ± 0.1

Benzyl Benzoate 2630 0.5 ± 0.4 1.3 ± 0.6

2. A formulation of essential oils with insect repellent properties according to claim 1, characterized in that it comprises a combination of two essential oils selected from the group comprising orange essential oil (Citrus sinensis), ylang-ylang essential oil {Cananga odoratá), essential oil of lemongrass (Cymbopogon citratus), essential oil of patchouli (Pogostemon cablin), essential oil of eucalyptus (Eucalyptus sp.), essential oil of palmarrosa (Cymbopogon martinii), and essential oil of citronella (Cymbopogon nardus), dissolved in an ethanol or alcohol in proportions of claim 1.

3. An essential oil formulation with insect repellent properties according to claim 1, characterized in that it comprises a combination of three essential oils selected from the group comprising orange essential oil (Citrus sinensis), ylang-ylang essential oil {Cananga odoratá), essential oil of lemongrass (Cymbopogon citratus), essential oil of patchouli (Pogostemon cablin), essential oil of eucalyptus (Eucalyptus sp.), essential oil of palmarrosa (Cymbopogon martinii), and essential oil of citronella (Cymbopogon nardus), dissolved in an ethanol or alcohol in proportions of claim 1.

4. A formulation of essential oils with insect repellent properties according to claim 1, characterized in that it comprises a combination of four essential oils selected from the group comprising orange essential oil (Citrus sinensis), ylang-ylang essential oil (Cananga) odoratá), essential oil of lemongrass (Cymbopogon citratus), essential oil of patchouli (Pogostemon cablin), essential oil of eucalyptus (Eucalyptus sp.), essential oil of palmarrosa (Cymbopogon martinii), and essential oil of citronella (Cymbopogon nardus), dissolved in an ethanol or alcohol in proportions of claim 1.

5. The formulation according to claim 1, characterized in that it comprises