FR2759546A1 - Use of citronella components as insecticides - Google Patents

Abstract

The use of citronnellol, citronnellal, and citronnellyl acetate, in insecticidal compositions, is new.

Description

 The present invention relates to insecticide compositions, in particular for destroying human parasites. The invention relates in particular to the compositions which can be used for the destruction of lice and nits.

 It is known from French patent no. 2,371,190 of November 28, 1976 (GB-1,593,601 of November 22, 1977) insect repellent complexes comprising a wetting agent, an acid, such as acetic acid, to have a pH fairly low, and an essential oil such as lemongrass, and possibly camphor.

 These products have been shown to be effective, in particular, as shampoos for eliminating lice and nits, and it has been shown that the first three constituents form a remarkable synergy.

 The use of natural essential oils (cloves, lavender, peppermint, oregano, lime, rosemary, juniper, lemon, lemongrass, thyme, datura stramonium, pyrethrum, cinnamon, etc.) has one drawback, with regard to current regulations, since it is not possible to indicate the very approximate composition of the product marketed. An essential oil like lemongrass has several tens of constituents, around 80, and the proportions can vary from one sample to another. It is not possible to specify all the constituents, nor the proportions of each.

 Various studies have been carried out so far to deepen the knowledge relating to essential oils of plants.

 In the review "Plantes rnédicinales, et Phytothérapie", 1989, tome XXIII, n. 2, pages 95-108, R. Gauthier, A.

Agoumi and M. Gourai publish a study on the activity against head lice of myrtle extracts, and in particular the action of light terpenes (a-pinene, b-pinene, camphene, limonene, cineole), alcohols (linalool, a-terpineol, myrtenol, nerol, geraniol) and esters (linalyl, terpinyl, myrtenyle, geranyl). The conclusion of this study is that volatile extracts repel lice, and that products in the gaseous state become very effective.

Lice mortality is thought to be due to cineole and lsa-pinene.

 Assuming that many of these constituents probably had little, if any, action, the inventor undertook research and experimentation with a view to determining which of the constituents could give the product its remarkable properties.

 Gas chromatography made it possible to know the compositions of essential oils.

The review "Analyst", October 1984, volume 109 discloses monographs of seven essential oils (lemongrass, clove, juniper berry, squeezed lemon, lime blossom, nutmeg from India, and black pepper). "Application of Gas
Liquid Chromatography to the analysis of Essential Oils ".

 The review "Perfumer and Flavorist", volume 2, February / March 1977 indicates the compositions of different essences of lemongrass (Ceyian, Java).

The main components of lemongrass essence are lemongrass, geraniol and lemongrass. The formulas and references for these products are given in the Merck Index. Let’s remember the lemon grass formula

 Studies done to date have shown some repellency for these products.

 In accordance with the present invention, it has been found that citronnellol and citronnellal have great insecticidal power and make it possible to make lotions and shampoos.

 Studies and research carried out in accordance with the present invention have shown that citronnellol and citronnellal, in combination with acetic acid, develop insecticidal power against certain insects including head lice and other parasitic lice species of humans. This power is improved in the presence of a wetting agent, as well as in the presence of camphor.

 Citronella and citronella are likely to react with acetic acid to form citronella acetate in an equilibrium esterification reaction.

 The study of citronellyl acetate has shown that this product also has an insecticidal action, which seems interesting since its presence is constant in the association acetic acid - citronnellol, although the maximum content noted remains low.

Furthermore, attempts to formulate citronnellol and citronnellal with solvents derived from paraffin and, in particular, from Isopar M have demonstrated an action complementary to that of these solvents, comparable to the insecticidal action obtained in solutions of
Permethrin and Malathion in Isopar M.

 Different compositions have been prepared for carrying out comparative tests. The compositions studied included either for the shampoos a wetting agent (sodium lauryl ether sulphate and sodium chloride to give the mixture a certain viscosity, or for the lotions a solution of lemon grass and lemon grass in Isopar M.

 Citronnellol can be extracted from natural essences.

It can be made from lemongrass, which is found to be 38 to 42% in the essence of lemongrass, while lemongrass is only found to be 8 to 12%. It can also be made from common organic products, such as mint.

 American patent US-3,025,730 describes a process for the manufacture of citronnellol by synthesis, from readily available and inexpensive materials.

 The Chem. Soc. Jpn., 62, 3779-3782 (1989) describes reactions of regioselective hydrogenation of unsaturated alcohols with the use of platinum-alumina catalysts modified by the carboxylic acid. In particular, it is possible to hydrogenate geraniol to transform it into citronnellol.

Comparative tests have been carried out. The following compositions were prepared
A / 80% acetic acid 4.56%
Camphor 0.76%
HE of lemongrass 0.76%
C1 Na 4.87%
Lauryl Ether Sodium Sulfate (Texapon) 36.55%
Water qs 100%
B / 80% acetic acid 4.56%
Camphor 0.76%
Geraniol 0.76%
Cl Na 4.87%
Lauryl Ether Sodiurn Sulfate (Texapon) 36.55%
Water qs 100%
C / 80% acetic acid 4.56%
Camphor 0.76
Citronnellol 0.76%
C1 Na 4.87%
Lauryl Ether Sodium Sulfate (Texapon) 36.55%
Water qs 100% C '/ Acetic acid 80% 4.56%
Citronella 10%
Cl Na 4.85%
Lauryl Ether Sodiurn Sulfate (Texapon) 36.55%
Water qs 100%
D / 80% acetic acid 4.56%
Camphor 0.76%
Cl Na 4.87%
Lauryl Ether Sodium Sulfate (Texapon) 36.55%
Water qs 100%
E / 80% acetic acid 4.56%
Camphor 0.76%
Citronellyl acetate 0.76%
C1 Na 4.87%
Lauryl Ether Sodium Sulfate (Texapon 36.55%
Water qs 100%
F / 80% acetic acid 4.56%
Carnphre 0.76%
Citronellyl acetate 0.76%
Citronnellol 0.76%
C1 Na 4.87%
Lauryl Ether Sodium Sulfate (Texapon) 36.55%
Water qs 100% G1 Lotion I
Citronella 2%
Solvent Isopar M 98% H1 Lotion Il
Citronella 10%
Isopar M solvent 98%
Lotions are prepared with 1 to 10% Citronnellol or Citronnellal with the supplement in Isopar M or another solvent.

 Formula A is that of a conventional shampoo sold commercially under the brand YSOL. it contains lemongrass essential oil in combination with acetic acid and a wetting agent.

In formula B, the essence of lemongrass is replaced by Geraniol, in formula C with
Citronnellol and in formula C 'by Citronnellal. Formula D contains neither lemongrass nor lemongrass extract.

 In formula E, the lemongrass of the shampoo was replaced with lemongellyl acetate, and in formula F, we introduced lemongellol and lemongellyl acetate.

The test is carried out on adult lice of P. humanus, raised in the laboratory (breeding strain, Laboratory of Hydrology, Environment, Bio-organic Chemistry, Section
Pesticide from Tours). These lice are fed on rabbits
White albinos from 3 to 4 kg (exclusively reserved for the blood supply of lice). . Adult lice and nits, outside of their contact during the daily meal with the rabbit, are kept in an oven at 29 "C and 70-809Ó relative humidity.

Method - Pour each of the products to be tested into a box of
Petri.

- Immerse the tissue carrying
lice and nits in the product, remove them at the end
of 3 minutes and place them in another box of
Petri dish dries for 15 minutes.

- After this action time, recover the tissues and
squeeze into a container of running water.

- Place the fabrics on filter paper for 15
minutes.

- At the same time, lots of witnesses are simply immersed
in running water, dried on filter paper for
15 minutes and put under observation.

- The fabrics are taken up and placed in boxes of
Petri dish at room temperature, 210C.

- Observations are made at 30 minutes and 24 hours
after the operation.

The results carried out on colonies of 10, 15 or 30 lice are collated on the following table (V = alive,
KD = knock down, M = dead)
TO T + 30 minutes T + 24 hours
V KD MV KD MV KD M
A 10 0 0 1 9 0 1 0 9
B 10 0 0 10 0 0 8 0 2
Witness 10 0 0 10 0 0 10 0 0
C 30 0 0 0 30 0 0 0 30
D 30 0 0 3 27 0 21 0 9
E 15 0 0 0 15 0 0 0 15
F 15 0 0 0 15 0 0 0 15
G 15 0 0 0 15 0 0 0 15
H 15 0 0 0 15 0 0 0 15
C '30 0 0 0 30 0 0 0 30
These tests confirm the important action of the citronella essential oil in sample A.

Sample B containing geraniol is ineffective. Samples C and C 'containing lemon grass and lemon grass are the most effective. Sample D containing no essence is ineffective. There is only a slight action due to the carnphre and acetic acid.

Finally, sample F, with citronnellol and citronnellyl acetate is effective, as well as samples G and
H with Isopar M.

 Clinical tests.

 In order to verify the results obtained in vitro, an open study was carried out on three groups of ten children in several schools.

 The following formulas were applied two times 7 days apart.

R 201 Sharnpooing
Acetic acid 3.85%
Lemongrass essential oil 0.74
Camphor 0.76%
Texapon 36.5%
Sodium chloride 3.85%
Water qs 100 ml
R 202 Shampoo
Acetic acid 3%
Citronella 2%
Texapon 36.5%
Sodium chloride 3.85%
Water qs 100 ml
R 203 Citronella Lotion 5%
Isopar M 95%
For this formula, a shampoo was made 10 hours after the treatment.

 After two treatments at OJ and D7, the controls at D14 showed that only one living louse was on one of the children treated with the formula R 201, but none on the children treated with the formulas R 202 and R 203.

 Dead young lice have been found in children treated with the R 201 formula, but not in the R 202 and R 203 formulas, thus showing that these two formulas have a better lenticidal efficacy than the R 201 formula.

The tolerance was excellent with the R 201 formulas,
R 202 and R 203.

Claims (7)

Claims  1.- Use of compounds of the citronnellol, citronnellal and citronnellyl acetate families in insecticide compositions.  2. An insecticidal composition according to claim 1, in particular usable as a shampoo for the destruction of head lice and nits, comprising acetic acid and an extract of a plant essence, characterized in that the extract of plant essence is citronnellol or citronnellal or citronnellyl acetate in the proportion of 0.5 to 10% for all the compounds of the family.  3. A composition according to claim 2, comprising a wetting agent, such as sodium lauryl ether sulfate and sodium chloride.  4. A composition according to claim 2 or claim 3, further comprising camphor in an amount of 0 to 5%.  5. - Composition according to any one of the preceding claims, having the following proportions, with one or other of the active principles  80% acetic acid 1 to 5  Camphor 0 to 5 9.  Water q.s.p. 100%  Wetting agent 10 to 40%  Sodium chloride 0 to 5%  Citronnellol or Citronnellal 0.5 to 10 e  Citronellyl acetate 0 to 5 2  6.- Composition according to claim 1 comprising from 1 to 10% of the compounds of said family and 99 to 90% of a solvent.  7. A composition according to claim 6, in which the solvent is Isopar M.