GB2140299A - Use of haloalkynyl carbamates in treating micro-organisms - Google Patents

Abstract

A method for repelling, controlling or destroying aquatic invertebrates or lower vertebrates comprises using an iodoalkynyl carbamate of the formula [I-C IDENTICAL C-(CH2)n-O-CO-NH]mR wherein m is 1, 2 or 3; n is 1, 2 or 3; and R is a C1-20 hydrocarbon.

Description

SPECIFICATION The use of haloalkynyl carbamates in treating micro-organisms The present invention relates to the use of haloalkyl carbamates in treating micro-organisms.

US-A-3923870 describes urethanes of i-halogen-substituted alkynes and their fungicidal activity. US-A-4276211 describes the use of urethanes of i-halogen-substituted alkynes and combinations of these compounds with epoxides to provide colour-stabilised fungicides for use in coatings.

Certain carbamates have been employed as insecticides and herbicides. The insecticide Seven (carbamyl or naphthylmethyl carbamate) is known to be algacidal at between 1 and 100 ppm.

However, even tested at 100 ppm, it only reduced the population of an axenic culture of Chlorella pyrenoidosa by 30% (Christie, 1969, "Pesticide Microbiology").

"Zectran", a mexacarbate formulation, has been claimed to prevent photosynthesis in bluegreen algae (bacteria). However, in "normal" spray applications it did not pose a threat to aquatic algae (Snyder and Sharidan, 1974).

Phenyl carbamates, frequently employed as herbicides, have demonstrated activity against blue-green algae. Propham, Chloropropham and Barban have caused a 50% reduction in the growth of blue-green algae at between 0.3 to 70 ppm (data from Hill and Wright, 1978).

Barban did not inhibit all of the algal species tested.

British Patent Application No. 8321930 (Serial No. ) discloses and claims the use of urethanes of 1-halogen-substituted alkynes as algacides.

Compounds and compositions often employed against aquatic pests include various compounds of copper, tin and zinc, creosote, halogenated phenols and others. Copper, tin and zinc oxides are employed because of their low cost rather than because they have high activity. More expensive organometaliic compounds are employed because of their high activity against particular organisms or groups of organisms. Each of the known toxicants has its own unique and specific biocidal spectrum of activity and most have disadvantages, including environmental problems.

It is known to use mercury compounds as marine and aquatic toxicants. They have limited effectiveness and toxicity shortcomings. Tributyltin oxide has been used, but it is relatively expensive, and shows unsatisfactory stability for exterior exposure.

Although various compounds have been employed for limited use in lakes, ponds and areas of stagnant water, there has not been a wide recognition of the need for algacides in coatings until recently. It has been found possible to "load" certain compositions with materials such as zinc oxide but this causes problems in pigmented paints and coatings, has low algacidal activity and gives stability problems.

For special applications in water towers such as cooling and holding towers, materials such as chlorine and sodium hypochlorite have been used, especially as algacides. However, these materials are presently considered unacceptable by the U.S. Environmental Protection Agency at least, and may be environmentally hazardous.

According to the present invention, a method for repelling, controlling or destroying aquatic invertebrates comprises using an iodoalkynyl carbamate of the formula [I C=C(CH2)n0C0N]rnR wherein m is 1, 2 or 3; n is 1, 2 or 3; and R is a C1 20 hydrocarbon carrying the m iodoalkynyioxycarbonylamino and, optionally, other substituents.

It has been found that the carbamates used in this invention can control and destroy various species of aquatic invertebrates. They are very stable, even when incorporated into aqueous and non-aqueous compositions, including sea-water, and are deactivated and/or destroyed only by prolonged exposure to high temperatures. In addition, they have been shown to be relatively harmless to useful motile vertebrate animals.

Further, the ca;bamates possess only low toxicity towards animals, birds and other wildlife, domestic animals and man. Consequently, their use requires only the usual good practice and procedures in handling, and such precautions as are well established and in use for handling commercial, household, and marine biocides and toxicants.

s desired or necessary, the carbamates can be combined with other biocides, to broaden and enhance their activity and to extend the areas of their usefulness. The compositions in which they are used may contain any of a variety of components which are well-known in the art. In many instances, they will be used in sea-water.

The carbamates may be formulated into suitable compositions in amounts of from 0.001 to 12.0% by weight, in some cases depending on their stability in the compositions, the medium in which they are employed, and whether the composition is aqueous or non-aqueous. In some instances, the compounds may be employed as premixed dispersions. They may also be prepared as solutions or dispersions and thereafter added to the aqueous medium in which they are employed. For example, 3-iodo-2-propynyl butylcarbamate is soluble in water at a level of about 150-200 ppm.

In use, the amount (concentration) of the carbamate effective to accomplish control and/or destruction of the particular species of aquatic invertebrate may of course vary. For instance, in some cases, it may be necessary to employ up to 15% by weight of the compound, to destroy certain undesirable marine animals, but a lesser concentration will function effectively as a repellent.

For the uses described herein, the carbamates, e.g. dissolved or dispersed in water, can be incorporated into or coated on to a wide variety of compositions which require protection and freedom from marine animals, including paints, coatings, caulkings, linings, sealants, sprays, lacquers, finishing compositions, polishes, wood, mortar, concrete, cement, fillers, moulding compounds, waxes, resins, polymers and fibres. The carbamates are active for control against aquatic species found in marine, fresh water, terrestrial and aerial situations. They are also active against certain species found in water-cooling towers, irrigation canals, and in growth on mortar and wood.

The compositions may be, for example, any type of water-based latex paint (incorporating acrylic and PVA latex paints and chlorinated rubber-vinyl paints), an oil alkyd paint, an oil-based stain, a pigmented paint, a protective or other type of composition, a rubber and/or asphaltcontaining coating, an inorganic or polymeric caulking, a moulding material, sealant, silicone composition or liquid composition, either aqueous or non-aqueous, adapted for painting, dipping and/or spraying.

The invention is of particular value for applications in clogging problems in irrigation ditches, canals and conduits, as well as around docks and marinas and on water-craft where marine animals may be particularly troublesome and difficult to control. The carbamates appear to have a unique spectrum of activity against aquatic pests involved in biofouling. They are active against wood-boring aquatic invertebrates and repellent towards other aquatic invertebrates, Aquatic invertebrates demonstrating the avoidance response can be desirable species which are repelled and thereby escape to safety. They can also be undesirable species which settle on unprotected substrates such as wood, resins, fibrous materials, hair, wool, paper and paper substitutes.

in addition, the carbamate compounds may exhibit varying degrees of toxicity as well as repellancy characteristics towards motile aquatic life in general. The fact that they also exhibit characteristics of repellancy limits and modifies their toxic effects and since, usually, large volumes of water are involved, this serves as an effective diluent.

In particular, the method of the invention can be used for repelling, destroying or controlling aquatic invertebrates such as aquatic protozoa, hydrozoa, bryozoa, planaria, barnacles, shipworms, snails, mussels, coloenterates, mulluscs, mosquito larvae and tunicates.

The carbamates used in the present invention are of the given formula, in which m and n are independently selected from 1, 2 and 3, each preferably being independently selected from 1 and 2. R may be an alkyl, aryl, aralkyl, alkaryl, alkenyl, cycloalkyl or cycloalkenyl compound having up to 20 carbon atoms. The preparation of such compounds is known. Illustrative processes are described in British Patent Application No. 8321930 (Serial No. ). The preferred compound for use in the present invention is 3-iodo-2-propynyl butylcarbamate (also known as Polyphase, a Trade Name of Troy Chemical Corporation).

The following Examples illustrate the invention. "Ward" refers to Ward's Natural Science Establishment, Rochester, New York, U.S.A. as a source of organisms.

The repellant-toxicant solutions employed in the Examples were prepared by one of two methods. In the first method, 100 mg of the compound were dissolved in distilled water in a 1000 ml volume flask, and the mixture was brought to volume with water. This solution contained 100 ppm of the compound, which was subsequently diluted. In the second method, 1 g of the compound was dissolved in acetone in a 100 ml volume flask, giving a solution containing 10,000 ppm of the compound. Dilutions were made using either fresh or sea-water as required and indicated. Suitable controls containing the same levels of acetone were employed when the second method was used to prepare the test solutions.

EXAMPLE 1 Known volumes of fresh agnotobiotic cultures of protozoa (Ward), having adequate growth, were transferred to fresh media and employed as inocula. Depending upon the species being studied, tubes receiving the inocula contained a medium and/or sterile water (controls). Known volumes of aqueous solutions containing 3-iodo-2-propynyl butylcarbamate were added, and the concentration of the carbamate calculated from the total volume.

The test cultures were incubated for a controlled length of time and then examined microscopically. Active protozoa were observed in controls and at failing levels of the compound being tested. The absence of protozoa indicated that that level had effectively killed the protozoa.

The protozoa employed in these tests are usually found in many kinds of aquatic ecosystems.

A number of the major and most commonly-occurring taxonomic groups of protozoa were presented in the tests. The results were as tabulated below.

3-iodo-2-propynyl butylcarba mate (ppm) Protozoan Alive Killed Actinospherium 9 16 Blepharisma 14 16 Chilomonas 1 5 25 Paramecium 9 16 Tetrahymena 9 16 EXAMPLE 2 Axenic cultures of protozoa were obtained from Ward or the American Type Culture Collection. Known volumes of fresh cultures, shown to have adequate growth by examination, were employed as inocula. Depending upon the species, tubes receiving the inocula contained known volumes of sterile agar (slants) and overlays, a sterile liquid medium and/or sterile water (controls). Known volumes of aqueous 3-iodo-2-propynyl butylcarbamate solutions were added and the carbamate concentration calculated from the total liquid volume. The volume of agar was disregarded in the calculation.Therefore, the values obtained as calculated represent the highest level of exposure during the test.

The test cultures were incubated and then examined microscopically. Active protozoa were observed in controls and at failing levels (levels with low or inadequate activity). The absense of protozoa indicated that that level had effectively killed the protozoa.

Protozoa as described above are pathogenic in invertebrate and/or vertebrate animals. In one instance (Tsypanosoma cyclops), the pathogen came from monkeys and was a potential human pathogen (Class Ill). The results of these tests were as tabulated below.

3-iodo-2-propynyl butylcarbamate (ppm) Protozoan Alive Killed Crithidia faciulata 1 7 29 Herpotomomas muscarum 1 7 23 Herpetomonas samuelpessoai 29 38 Leishmania adleri 40 46 Leishmania algamae 60 65 Leishmania hertigii 65 70 Leishmania tarentolae 55 60 Tritrichromona augusta 10 1 5 Trypanosoma cyclops 30 40 Trypanosoma ranarum 29 44 EXAMPLE 3 Specimens of the scyphozoan Aurelia aurita were obtained from the Marine Biological Laboratory at Woods Hole, Massachusetts, U.S.A.These specimens were maintained in well aerated aquaria provided with under-the-gravel filters, limestone gravel bottoms and pieces of wood to provide surfaces for attachment. 3-lodo-2-propynyl butylcdrbamate solutions were prepared in artificial sea-water and tests were carried out in 1.5 litre aquaria. These aquaria were similar to holding tanks, except that sea-water was not filtered and aeration was provided through air stomas.

Animals were held in the solutions over a weekend period (2-2+ days) and examined.

Animals killed by the solutions did not demonstrate an avoidance response to touch and rapidly decomposed. Living animals demonstrated an avoidance response and moved about when returned to the holding tanks. The lowest level which was toxic and killed Aurelia aurita was 10 ppm (20 yg/ml) of 3-iodo-2-propynyl butylcarbamate.

The following compounds are also found to be equally or somewhat less toxic towards Aurelia aurita: 4-iodo-3-butynyl methylcarba mate 3-iodo-2-propynyl cyclohexylcarbamate 3-iodo-2-propynyl octylcarbamate 3-iodo-2-propynyl phenylcarbamate 3-iodo-2-propynyl 4-chlorophenylcarbamate 3-iodo-2-propynyl benzylcarbamate diphenylmethane-4,4'-dicarbamic acid bis(3-iodo-2-propynyl) ester EXAMPLE 4 Hydroids belonging to the genera Obelia and Tubularia were tested as described in Example 1, except that the hydroids were attached to marine algae which were placed in the test aquaria.

Obelia and Tubularia were killed by 1 ppm (1 ,ug/ml) of the carbamate (which was the lowest level tested). Suitable controls without use of the carbamate contained living hydroids at the end of the experiments.

EXAMPLE 5 Two species of bryozoa were obtained and tested as described in Example 1. The first species came from the Marine Biological Laboratory and was killed by 5 ppm (5 pg/ml) of 3-iodo-2propynyl butylcarbamate. The second species was obtained from Cape Fear Biological Supply Co., Southport, North Carolina and was killed by 25 ppm (25,ug/ml) of 3-iodo-2-propynyl butylcarbamate.

EXAMPLE 6 Turbatrix medium (Ward) was combined with an aqueous 3-iodo-2-propynyl butylcarbamate solution (1000 ppm) in screw cap test tubes in various ratios. The resulting levels were 10, 20, 30, 40 and 50 ppm of the carbamate. Controls were prepared by combining the medium with distilled water. The tubes were each inoculated with one drop of active Turbatrix aceti culture (Ward) and incubated for 7 days.

Active animals were found in all controls and at 10 ppm. The nematodes were killed at 20 ppm and higher and no animals were observed microscopically in the solutions at the killing concentrations level.

The same seven compounds as given at the end of Example 3 were found to be equally or somewhat less toxic towards Turbatrix aceti.

EXAMPLE 7 A wood-boring isopod species, Sthaeroma quadridemtum, was obtained from Cape Fear Biological Supply Co. and tested for its sensitivity to 3-iodo-2-propynyl butylcarbamate.

Solutions having a volume of 10.0 ml were prepared in test tubes and the animals transferred to the tubes. The lowest toxic level of the carbamate was 30.0 ppm (30,ug/ml).

EXAMPLE 8 Three cultures of different planaria (Ward), representing different genera and species, were picked up on the end of a spatula and transferred to test tubes containing aqueous 3-iodo-2propynyl butylcarbamate solutions. Five animals were employed in each test, at O (distilled water control), 10, 18, 25 and 31 ppm of the carbamate. All of the animals belonging to the three genera survived in the distilled water control. All were killed in less than two hours at or above 10 ppm carbamate.

The same seven compounds as given at the end of Example 3 were found to be equally or somewhat less toxic towards Planaria.

EXAMPLE 9 Barnacles belonging to the genera Balanus, Chathamalus and Polycites were obtained from the Marine Biological Laboratory, Cape Fear Biological Supply Co. and Gem Cultures, Fort Brag, California. These animals were tested as described in Example 1. The results of these experiments are shown in the following Table: Minimum Toxic Common Name Organism Level (ppm) Acorn Barnacles Balanus amphitrittii 1.0 Beburneus 0.8 Chathamalus frigilus 5.0 Goose-necked Barnacles Polycites polymerus 50.0 EXAMPLE 10 Two planks (15 cm wide X 10 cm thick) containing living shipworms (Toredo bankie) were obtained from Cape Fear Biological Supply Co. They were cut into 25 cm lengths and held in two pails containing either artificial sea-water or a saturated solution of 3-iodo-2-propynyl butylcarbamate in sea-water (total volume 80 litres each).After 5 days exposure, the planks were split open with a hammer and chisel. The control without the carbamate, contained living shipworms (5 worms detected), whereas alloy the shipworms (7 worms) were killed by the saturated carbamate solution.

This Example illustrates activity against lower vertebrates.

EXAMPLE 11 A total of 100 Limnoria were removed from cultures and placed in each 500 ml beaker. The beakers contained 0 (control without acetone), 0 (control with acetone), 1, 5, 10, 25 and 50 ppm 3-iodo-2-propynyl butylcarbamate in filtered Auxbury Bay sea-water. The beakers were monitored after 24, 48 and 96 hours and the number of dead Limnoria counted at the end of each observation. The numbers were examined statistically and the LC50 calculatd to be 18.6 ppm with 95% confidence limits of 16.86 to 20.59 ppm. The data were: 3-iodo-2-propynyl Number Dead (hrs) butylcarbamate Total (ppm) 24 48 96 Dead r 0 2.2 0.0 0.1 2.3 1 1 0 1 2 5 3 0 0 3 10 2 6 2 10 25 40 13 22 75 50 100 - - 100 EXAMPLE 12 Three species of snails were tested.Two belonged to the genera Ampulana (Ward's No. 87 W4121) and Planorbis(Ward's No. 87 W4161) and one species was unidentified (Ward's No 87 W4101). Three snails of each species were employed in each test in aqueous 3-iodo-2propynyl butylcarbamate solutions. The levels tested were 0 (distilled water control), 5, 10, 15, 20 and 25 ppm of the carbamate. Snails were held in the test solutions for 24 hours. All of the snails survived at 0 and 5 ppm of carbamate. All of the snails were killed at 10 ppm and higher of the carbamate.

The same seven compounds as given at the end of Example 3 were found to have about the same order of toxicity towards Ward's No. 87 W4101.

EXAMPLE 13 The interiors of each of two 1 9 litre (5 gallon) pails were divided vertically in half with a pen.

One half of each pail was painted with an unprotected oil alkyd paint. The other half of one pail was unpainted and the other half of the second pail was painted with the same alkyd paint also containing the equivalent of 7 g 3-iodo-2-propynyl butylcarbamate per litre (6 Ib per 100 gallons) of paint.

The paint was dried over four days. The pails were then filled two thirds full with water and 10 Planorbis snails (Ward) were distributed at random in each pail. The snails were held in the pails overnight, when it was found that they were randomly distributed on painted and unpainted surfaces in the first, control pail; in the second pail, the snails demonstrated an avoidance response and were repelled from the carbamate-containing paint. They were found only on the unpainted surfaces in this pail.

EXAMPLE 14 Fresh-water mussels (genus Unio) (Ward) were subjected to the experimental procedure described in Example 1, except that sand was employed as the bottom material and fresh water rather than sea-water. The mussels demonstrated an avoidance response; by tightly closing their shells, they were able to survive exposure to 100 ppm of the carbamate for 24 hrs.

EXAMPLE 15 Mosquito larvae were added to aqueous solutions of 3-iodo-2-propynyl butylcarbamate having a total volume of 100 ml. The larvae were killed by a concentration of 8 ppm (80 g/ml) in less than 24 hrs. Mosquito larvae survived in controls and at lower levels.

EXAMPLE 16 The sensitivity of the tunicate Styella partita, obtained fro Cape Fear Biological Supply Co.

was determined as in Example 1. The lowest level which killed the animals was 25 ppm. The tunicates are usually classified ith the Urochordata, which are considered to be lower vertebrate pests rather than invertebrates.

EXAMPLE 17 The carbamates toluene-2,4-dicarbamic acid bis(3-iodo-2-propynyl) ester and 3-iodo-2-propynyl ethylcarbamate were tested against acorn barnacles belonging to the species Balanus eburneuswhich is commonly called the ivory barnacle. The procedure employed is described in Example 1. The respective minimum lethal concentrations were 16.0 and 5.0 ppm.

The Examples illustrate the very wide range of aquatic pests which are known to be involved in either biofouling and/or the destruction of wood in the marine environment. The organisms killed were generally sessile pests. Some motile invertebrates which may be considered to be desirable are repelled by the carbamates. Undesirable organisms are also repelled, so that the carbamate provides protection from their undesirable and destructive activities.

Claims (21)

1. A method for repelling, controlling or destroying aquatic invertebratedor lower vertebrates, which comprises using an iodoalkynyl carbamate of the formula [ICC(CH2)nOCON H]mR wherein m is 1, 2 or 3; n is 1, 2 or 3; and R is a C10 hydrocarbon carrying them iodoalkynyloxycarbonylamino and, optionally, other substituents.

2. A method according to claim 1, in which m is 1.

3. A method according to claim 1, in which m is 2.

4. A method according to claim 1, in which m is 3.

5. A method according to any of claims 1 to 4, in which n is 1.

6. A method according to any of claims 1 to 4, in which n is 2.

7. A method according to claim 1, in which the carbamate is 3-iodo-2-propynyl butylcarbamate.

8. A method according to any preceding claim, in which the aquatic invertebrates cause or contribute to marine biofouling.

9. A method according to any preceding claim, in which the aquatic invertebrates cause or contribute to the destruction of wood or wood products in aquatic systems.

10. A method according to any preceding claim, in which the carbamate is a repellent for aquatic invertebrates which are motile.

11. A method according to any preceding claim, for repelling, controlling or destroying aquatic invertebrates.

1 2. A method according to any of claims 1 to 7, for repelling, controlling or destroying sessile lower vertebrates.

1 3. A method according to any of claims 1 to 12, which is used on protozoa.

14. A method according to any of claims 1 to 12, which is used on aquatic molluscs.

1 5. A method according to any of claims 1 to 1 2, which is used on aquatic worms.

1 6. A method according to any of claims 1 to 12, -which is used on aquatic snails.

17. A method according to any of claims 1 to 12, which is used on mosquito larvae.

1 8. A method according to any of claims 1 to 12, which is used on tunicates.

1 9. A method according to any of claims 1 to 12, which is used on barnacles.

20. A method according to any of claims 1 to 12, which is used on coelenterates.

21. A method according to claim 1, substantially as described in any of the Examples.