IMPROVEMENTS OF A PESTICIDAL/INSECT REPELLENT COMPRISING SYNTHESIS OF A NEW PESTICIDAL INSECT REPELLENT.

The present invention relates to improvements of pesticidal compositions comprising methods to synthesize or produce a new pesticidal/insect repelling substance.

In Australian Patents 608281, 608564, 607922, and

Patent application 26320/88, the present applicant describes the use of azadirachtin rich extracts of neem seeds and other meliaceous plants to inhibit pests such as blowfly larvae, lice and fleas.

Azadirachin rich extracts from neem seeds have been used in Indian folk medicine for thousands of years and this, together with recent laboratory tests has shown neem seed extracts or meliaceous extracts with azadirachtin to be of very low toxicity to vertebrates.

It is an object of this invention to provide a new hereto unknown pesticidal/insect repelling substance and to provide a method to synthesize or produce the new insect or pest inhibiting substance. It is a further object of this invention to provide a method to improve the insecticidal/insect repelling properties of the pesticidal composition described in Patent PCT/AU90/00586.

The present invention thus provides a new pesticidal/ insect repellent substance and an improved pesticidal/insect repellent mixture by mixing 1 to 35% by volume of oil of citronella, from 2 to 30g per litre azadirachtin, from 30 to 200g per litre neem seed extract or extract of meliaceous plants containing 5% azadirachtin, from 30 to 200g per litre diethyl toluamide (DEET), from 6 to 46g per litre di-n-propyl isochinchomerate. from 1.5 to 10.5g per litre N-Octyl bicycloheptene dicarboximide, from 0.17 to 1.16 g per litre Triclosan and alcohol and lemon grass oil the remainder, and heating the mixture to between 30 and 200 ºC from 1 second to 1000 hours.

The invention also relates to a method of killing or repelling pests comprising applying the mixture and new molecule to the pests or their surroundings. The substances may be applied together or sequentially.

The invention also relates to a method of synthesizing Azadirachtins, nimbidens, protoliminoids, liminoids, or tetratriterpenoids, pentanortriterpernoids, including meliantrol, nimbocinone, azadirachtol and azadirachnol or changing the structure of the compounds shown on Drawing 1, page 1/3, present in extracts of meliaceous trees including neem tree extracts (Azadirachta Indica A.Juss.) or which have been synthesized artificially.

The invention also relates to a method or a process to increase the concentrations of the aforementioned substances present in meliaceous tree extracts including neem tree and seed extracts namely the tetratriterpenoids, pentanortriterpenoids, hexatriterpenoids, azadirachtins, salanninns, azadiradiones. nimidens and vilanisin and derivatives. These substances are illustrated on Drawing 1. page 1/3.

The invention also relates to a method or process to unbind or release the aforementioned substances illustrated on Drawing 1, page 1/3 from proteins, fats, oils or any other substances to which the substances illustrated on Drawing 1, page 1/3 bind in the extracts of meliaceous trees including neem seeds and extracts.

The invention also relates to a process or method to improve the pesticidal and insect repellent properties of the substances illustrated on Drawing l, page 1/3.

The invention also relates to a method to change the structure of the substances shown on Drawing 1, page 1/3, wherein the extracts of meliaceous trees including neem seed extracts are heated in absence or presence of air to between 30ºC and 200ºC for periods ranging between 1 second and 1000 hours.

The invention relates to a process or method to increase the concentrations, to unbind and improve the pesticidal and insect inhibiting properties of the substances shown on Drawing l page 1/3 wherein the extracts of meliaceous trees including neem tree and seeds extracts are heated in the presence or absence of air to between 30ºC and 200ºC for periods ranging between 1 second and 1000 hours.

Further embodiments of the invention shall become apparent from reference to the examples.

Example A

one litre of a liquid pesticidal/insect repelling

composition may be made by mixing the following:-

Oil of citronella 10 to 350ml

Meliaceous extracts

containing 5% azadirachtin 40 to 600ml or pure azadirachtin 2 to 30g

Triclosan 0.17 to 1.16g

N,N,Diethyl-M-Toluamide 30 to 200g

Di-N-propyl Isochinchomerate 6 to 46g

Alcohol (e.g. Ethanol) Remainder

Lemon Grass oil Traces

Comparitive Example 1a

Four samples of the mixture were kept at 4ºC for 14 days {Samples 1) and four samples were kept at 54ºC for 14 days (Samples 2).

0, 5, 20, 60, and 100 drops respectively, of Samples 1 or Samples 2 were blended with 10 grams of food containing 50 first stage larvae of the insect Lucilia cuprina. Each drop contained 5 microlitres (ul) of liquid.

Larval length or growth and larval survival in food blended with Samples 1 or Samples 2 are set out in Table la on the next page of this description.

Table 1a

Drops (number) 0 5 20 60 100

Dose (ul) 0 25 100 300 500

Samples 1$

Mixture stored at

4ºC for 14 days

Larvae Length(mm) 8.0+0.3 6.8+0.5 3.3+0.3 1.2+0.8 0 Survival (%) 96 86 43 12 0

Samples 2$

Mixture stored at

54ºC for 14 days

Larvae Length(mm) 8.0+0.3 3.2+0.2* 0* 0* 0* Survival (%) 96 11 0 0 0

$ = All tests duplicated (ie:Four samples for each concentration n=4) * = P< 0.05 larval length and survival was

significantly less in samples 2 compared to samples 1 (Two -way analysis of variance).

From a comparison of results in Table la it is apparent that heating at 54ºC for 14 days increased the pesticidal/insect inhibiting properties of the mixture. In fact, heating increased efficiency 53 to 100% over the range of concentrations tested.

Table 1b

Concentration of Active constituents including

azadirachtins, nimbins, triterpernoids, pentatriterpernoids, salannins vilasinins, liminoids in neem seed extracts heated between 30ºC and 70ºC for 1 second to 1000hours.

0 seconds 1000 hours

Concentration (5.) 1 5

A comparison of results in the table 1b shows that the concentration of the actives in neem seeds extracts increased five fold when exposed to heating.

Comparative example 1b

Drawing 2 on page 2/3 (drawings) shows the tracings representing the concentration of azadirachtin and other substances in meliaceous extracts in samples 1 kept at 4ºC for 14 days .

Drawing 3 on page 3/3 (drawings) shows the tracings representing the concentration of azadirachtin and other substances in meliaceous extracts in this case neem seed extract in Samples 2 kept at 54ºC for 14 days

From a comparison of Drawing 2 and Drawing 3 it is apparent that heating the pesticidal/insect repellent mixture created a new unknown substance.