DK174984B1 - Use of quinoline derivatives, their salts or hydrates for the preparation of antibacterial drugs for fish - Google Patents

Abstract

Antibacterial medicaments for fish contain 1-cyclopropyl-7-(1-piperazinyl)- 6-fluoro, 4-dihydro-4-4oxo-3- quinolinecarboxylic acid cpds. of formula (I) or their salts or hydrates; R1 = H, lower alkyl or lower hydroxyalkyl; R2 = H or lower alkyl. (I) are described in JA 71683/82 and 74667/83.

Description

DK 174984 B1

The present invention relates to the use of guinoline derivatives of general formula I

5 O

'E * Tf COOR, r ^ xcr 2 VNWN? Δ 10 in which

R 1 represents a hydrogen atom, a lower alkyl group or a lower hydroxyalkyl group, and R 2 represents a hydrogen atom or a lower alkyl group, their salts or their hydrates, with the exception of 1 - cyclopropyl-6-fluoro-1,4-dihydro-4 -oxo-7- (1-piperazinyl) - quinoline-3-carboxylic acid (ciprofloxacin), for the production of antibacterial drugs for fish, especially antibacterial drugs suitable for the prevention, cure and treatment of infectious diseases in fish, caused by microorganisms or aquatic microorganisms.

In recent times, due to the problems with the 25 200-mile fishing zones and the scarcity of overfishing, the fish stocks available for the catch are increasingly fish farming cultures. As a result of this trend, efforts are being made towards high-yielding fish farming. Particularly in high-density intensive fish culture, infectious diseases occur frequently in the fish, and if such diseases remain untreated, the damage occasionally amounts to a complete destruction of the fish culture in the farm. Even when no damage is done to this extent, the surviving fish are damaged and have a significant

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2 DK 174984 B1 equals impaired trading value. This problem occurs in many places and there is a strong need for its prompt and effective solution.

The majority of infectious diseases in fish are caused by microorganisms or living microorganisms, and so far, in practice, they have been working on their prevention or cure that antibacterial drugs such as sulfase, nitrofuran, synthesized penicillin, tetracycline, macrolide antibiotics, nalidixic acid. , 10 oxolinic acid, pyromic acid or chloramphenicol for oral administration to the fish are added to their feed, or infected fish are placed for a certain period in water in which such antibiotics are dissolved, a so-called medical bath.

However, the known antibacterial agents, such as those mentioned above, have the disadvantages that their antimicrobial spectra are narrow, their healing effect is weak, their safety margin (the distances between the effective dose and the toxic dose) are small, causing undesirable side effects , and their use is uneconomical and due to 20 of these conditions they are not very satisfactory.

It has now been found that the quinoline derivatives of the above general formula I, their salts and their hydrates have excellent preventive and curative effects in a broad sense against various micro-organisms and aquatic micro-organisms causing infectious diseases in fish, that they are also very effective against resistant bacteria and against complications, and having low toxicity, are metabolized safely and rapidly, and are extremely suitable as preventive and curable antibacterial drugs against infectious diseases of fish.

In the above formula I, the lower alkyl structural units of the "lower alkyl" and "lower hydroxy-alkyl" groups include straight or branched alkyl groups having up to 6 carbon atoms, preferably up to 4 carbon atoms, e.g. methyl, ethyl, n-propyl, iso-propyl, n-butyl, B1 sec-butyl, iso-butyl, tert-butyl, etc. The preferred examples of R 1 include hydrogen, methyl, ethyl and β-hydroxy. ethyl. For R 2, hydrogen, methyl and ethyl are also preferred.

5 Typical examples of the quinoline derivatives of formula I useful as active ingredients in the antibacterial agents of the present invention include the following:

Methyl 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-piperazino-quinoline-3-carboxylate, ethyl-1-cyclopropyl-6-fluoro-1,4-dihydro-4 -oxo-7-piperazino-quinoline-3-carboxylate, 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7- (4-methyl-piperazino) -quinoline-3-carboxylic acid, ethyl 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7- (4-methylpiperazino) -quinoline-3-carboxylate, 1-cyclopropyl-6-fluoro-1,4-dihydro-4 -oxo-7- (4-ethylpiperazino) -quinoline-3-carboxylic acid, ethyl-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7- (4-20 -ethylpiperazino) -quinoline -3-carboxylate and 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7- (4-8-hydroxy-ethylpiperazino) -quinoline-3-carboxylic acid.

The quinoline derivatives of formula I can be used in the form of acid addition salts utilizing the basicity of the piperazine group at the 7 position. Examples of such acid addition salts include salts with inorganic acids such as hydrochlorides, hydrobromides, hydroiodides and sulfates and salts with organic acids such as acetates, citrates, benzenesulfonates and embonates (pamoates). When R 2 in the quinoline derivatives of formula I is a hydrogen atom, the carboxyl group at the 3-position can also be present in salt form.

Such salts include alkali metal salts such as sodium or potassium salts, alkaline earth metal salts such as magnesium salts and calcium salts and ammonium salts, as well as physiologically acceptable salts and complexes of metals such as iron,

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4 DK 174984 B1 cobalt, copper, manganese, zinc and aluminum.

In addition, the quinoline derivatives of formula I or their salts can also be used in the form of their hydrates.

Most of the quinoline derivatives of formula I are compounds known per se, e.g. are disclosed in Japanese Publications Nos. 71683/82 and 74667/83, and can be prepared by the methods described in these publications.

For administration of the quinoline derivatives, their salts or their hydrates of Formula I (hereinafter referred to as the "active compounds of Formula I") as antibacterial drugs for fish, these compounds may be admixed with the fish feed for oral administration, or they may dissolves in the water in which you place the sick 15 fish and in which you let them swim around (a method below, the use of a so-called "medical bath").

In addition, the active compounds of formula I can be processed into suitable formulations for such administration forms as e.g. powders, granules or solutions such as feed additives or soluble dispersions or solutions for medical baths. The methods of preparing such formulations are similar to those used in the usual practice of the formulation of preventive or curative agents for acute attacks. According to conventional practice, one or more of various additives, e.g. extenders such as soybean protein, lactose, beer yeast and limestone, diluents such as water, solubilizers such as benzyl alcohol or n-butanol, thickeners such as hydroxypropylcellulose and pH regulators such as potassium hydroxide, sodium hydroxide, acetic acid and lactic acid, for the preparation of the desired formulation. The typical forms are explained in detail below.

DK 174984 B1

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Preparation Example 1 (Powder as Feed Addition):

Active compound of formula (I) 1-10 parts by weight

Soybean protein 99-90 parts by weight Total 100 parts by weight 5

The soybean protein is added to the active compound of formula I, and both are mixed homogeneously with each other in a mixer.

Preparation Example 2 (solution as a feed additive or for medical bath);

Active compound of formula (I) 0.5-10 parts by weight

Potassium hydroxide 0.08-1.5 parts by weight

Benzyl Alcohol 1.3-1.4 parts by weight Hydroxypropyl methylcellulose 50 0-3.5 parts by weight

Purified water Rest_ Total 100 parts by weight

The potassium hydroxide is added to the purified water and the mixture is stirred until a homogeneous system is present. To this is added the active compound of formula I, the benzyl alcohol and hydroxypropylmethylcellulose 50 and the mixture is stirred until uniform.

Preparation Example 3 (Soluble Powder for Medical Bath):

Active compound of formula I 1-10 parts by weight (one which is water soluble)

Lactose 99-90 parts by weight 30 Total parts by weight 100

The lactose is added to the active compound of formula I and both are mixed homogeneously with each other in a mixer.

35 6 DK 174984 B1

Preparation Example 4

Active compound of formula I 0.1-25 parts by weight

Potassium hydroxide 0.08 - 1.5 parts by weight

Potassium chloride 0.2 - 2 parts by weight 5 Benzyl alcohol 1.3 - 1.4 parts by weight

Glycine 0 - 2 parts by weight

Purified water Residue A total of 100 parts by weight 10 The potassium hydroxide and potassium chloride are dissolved in 50 ml of water, the active compound, benzyl alcohol, glycine and the remaining amount of water are added and stirred until the mixture is uniform.

Using the active compounds of Formula I as antibacterial drug for fish, the dosages administered vary depending on the purpose of the administration (prevention or cure of a disease) and the nature, degree and extent of infection of the target fish. for the treatment. Usually 20 a daily dose may be administered in the range of 5 to 1000 mg, preferably 20 to 100 mg per day. kg of body weight in the fish, either at one time or in several subsets at different times. However, it does not require any particular explanation that the above dose expresses a coarse standard that can be lowered or raised depending on the age, body weight, disease image, etc. The administration period is not subject to any particular limitations, but usually sufficient effects can be obtained within a period of time. one to approx. ten days.

The antibacterial drugs provided by the present invention are widely effective against various microorganisms or aquatic microorganisms that can trigger infectious diseases of fish. Eg. the drugs show a strong antibacterial effect against bacteria belonging to the genera Aeromonas, Edwardsiella, Pasteurella, Pseudomonas, Streptococcus and Vibrio, and they are therefore excellent

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7 DK 174984 B1 is effective in the prevention, treatment and cure of infectious diseases in farmed freshwater fish and marine fish such as young yellow tails, yellow tails ,. eels, ayus, trout, salmon, carp etc. and by aquarium fish such as goldfish and 5 tropical fish.

Such excellent effects of the antibacterial agents herein are demonstrated by the following in vitro and in vivo experiments using the following compounds.

Compound A: (use described in EP-A-0.219.784)

Hydrochloride of 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-piperazino-quinoline-3-carboxylic acid (decomposition point: 319-321 ° C).

Compound B: (Use described in EP-A-0.219.784) Monohydrate of the hydrochloride of 1-cyclopropyl-6-fluoro--1,4-dihydro-4-oxo-7-piperazino-quinoline-3-carboxylic acid. Compound C:

Hydrochloride of 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7- (4-methylpiperazino) -quinoline-3-carboxylic acid (decomposition point: 345-347 ° C).

Compound D: 1-Cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7- (4-ethylpiperazino) -quinoline-3-carboxylic acid.

Compound E: Dihydrate of the hydrochloride of 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7- (4-ethylpiperazino) -quinoline-3-carboxylic acid.

Compound F:

Hydrochloride of 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-30 -7- (4-8-hydroxyethylpiperazino) -quinoline-3-carboxylic acid (decomposition point: 327-333 ° C).

Compound G:

Embonate of 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7- (4-ethylpiperazino) -quinoline-3-carboxylic acid.

Compound H:

Ethyl 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7- (4-ethyl-piperazino) -quinoline-3-carboxylate (decomposition point: 187-189 ° C.

DK 174984 B1

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Compound OA (control): 1-Ethyl-1,4-dihydro-6,7-methylenedioxy-4-oxo-3-quinoline-carboxylic acid.

Experimental Example 1

Antibacterial action in vitro against fish pathogenic bacteria.

Each test strain was grown overnight, and each of the cultures containing ca. 106 cells per ml, pod thawed on Mueller-Hinton agar (Difco), to which was added 1.0 to 2.0% sodium chloride and containing the test compound at the concentration given in each case. The minimum growth inhibitory concentration (MIC) was determined for each compound after a 20 hour incubation period at 25-30 ° C. The results are given in the following Table I.

20 25 30 35 9 DK 174984 B1

TABLE X

Antibacterial effect in vitro against fish pathogenic bacteria (MIC, pg / ml).

5

Test Connection Control

bacterium ABCD EFGHQA

Pasteurella 10 piscicida EH8304 0.05 0.025 0.05 0.05 0.05 0.1 0.1 25.0 0.1 EH8309 <0.025 <0.0125 0.05 0.025 0.05 0.1 0.1 25 , 0.1 0.1 EH8312 0.05 0.025 0.05 0.05 0.05 0.1 0.05 12.5 0.1 EH8313 0.05 0.025 0.05 0.05 0.05 0.1 0.1, 05 12.5 0.1 NC8319 <0.025 0.025 0.05 0.025 0.05 0.1 0.01 25.0 0.1

Vibrio anguillarum NH8410 <0.025 0.025 <0.025 0.025 0.05 0.1 0.05 12.5 0.05 20 408340 <0.025 0.025 <0.025 0.025 0.05 0.1 0.05 25.0 0.05 NAB341 <0.025 0.025 <0.025 0.025 0.05 0.1 0.05 25.0 0.05 NA8346 <0.025 0.025 <0.025 0.025 0.05 0.1 0.05 12.5 0.05 NA8347 <0.025 0.025 <0.025 0.025 0, 05 0.05 0.05 12.5 0.05 25 Aercmonas hydrqphila KA8301 <0.025 <0.0125 <0.025 0.025 0.05 0.05 0.05 12.5 <0.0125 KA8414 <0.025 <0.0125 < 0.025 <0.0125 <0.025 <0.025 0.05 25.0 <0.0125 KA8416 <0.025 <0.0125 <0.025 <0.0125 <0.025 <0.025 0.05 12.5 <0.0125 30 M 183 < 0.025 <0.0125 <0.025 <0.0125 <0.025 <0.025 0.05 12.5 <0.0125 C 44 <0.025 <0.0125 <0.025 <0.0125 <0.025 <0.025 0.05 50.0 < 0.0125 35 o 10 DK 174984 B1

Experimental Example 2

Antibacterial action of compound D in vitro against various fish pathogenic bacteria.

Each test strain was grown overnight and each culture containing ca. 10 µl cells / ml were inoculated on Mueller-Hinton agar (Difco) to which 1.0 to 2.0% sodium chloride was added and containing the test compound at the concentration indicated in each case. The minimum growth inhibitory concentration (MIC) was determined for each compound after a 20 hour incubation period at 25-30 ° C. The results are given in the following Table II.

TABLE II

Antibacterial action of compound D in vitro against fish pathogenic bacteria

Experimental Number (MIC, Mq / ml) of bacterial strains Compound D Oxolinic Acid 20 Aeromonas hydrophila 25 <0.0125-0.05 <0.0125-0.025

Aeromonas salmonicida 0.0125-0.1 0.05-3.2

Edwardsielle tarda 25 0.025-0.2 0.05-1.6

Pasteurella piscicida <0.0125-0.05 <0.025-0.1

Pseudomonas anguilli- 18 <0.0125-0.025 <0.0125-0.05 septica

Streptococcus sp. 0.8 200-400

Vibrio anguillarum

Origin: yellow tail 25 0.05-0.1 0.025-0.05

Origin: ayu 0.025-0.4 0.05-25 30

Of the active compounds used in the above test examples, reference is made below to a preparation example of compound H.

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Preparation Example 1

To a suspension of 18 g of 1-cyclopropyl-7- (4-ethyl-1-piperazinyl) -6-fluoro-1,4-dihydro-4-oxo-quinoline-3-carboxylic acid in 120 ml of ethanol was added dropwise 24 g 5 96% concentrated sulfuric acid. The resulting mixture is heated to reflux for 12 hours and, after removing the excess alcohol under reduced pressure, the residue is dissolved in 200 ml of ice water. During ice cooling, the pH of the system was raised to 12-14 by adding a cold solution 10 of 19.2 g of sodium hydroxide in 100 ml of water and the precipitate formed in the meantime was filtered off by suction. The precipitate was then washed with water and dried at 100 ° C under reduced pressure. After recrystallization from toluene / light petrol, 10 g of the ethyl ester of 1-cyclopropyl-7- (4-ethyl-1-piperazinyl) -6-fluoro-1,4-dihydro-4-oxo-quinoline-3 was obtained. -carboxylic acid (52.5% of theory) with m.p. 187-189 ° C.

20 25, 30 35

Claims (2)

Use of quinoline derivatives of the general formula I νΟ ϊ xo Δ wherein R 2 represents a hydrogen atom, a lower alkyl group or a lower hydroxyalkyl group, and R 2 represents a hydrogen atom or a lower alkyl group, their salts or their hydrates, with the exception of 1-Cyclo-propyl-6-fluoro-1,4-dihydro-4-oxo-7- (1-piperazinyl) -quinoline-3-carboxylic acid (ciprofloxacin), for the preparation of anti-bacterial drugs for fish. Use according to claim 1, characterized in that 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7- (4-ethylpiperazine) -quinoline-3 is used as quinoline derivative of formula I carboxylic acid (enrofloxacin), its salts or its hydrates.