CA1302274C

CA1302274C - Antibacterial drugs for fish

Info

Publication number: CA1302274C
Application number: CA000529870A
Authority: CA
Inventors: Tadatoshi Kitao; Noboru Sekiguchi; Toshio Hayami
Original assignee: Bayer AG
Current assignee: Bayer Animal Health GmbH
Priority date: 1986-02-19
Filing date: 1987-02-17
Publication date: 1992-06-02
Anticipated expiration: 2009-06-02
Also published as: FI870657A; IE59365B1; NO870494D0; ATE77551T1; EP0238814A3; EP0238814B1; CN87100799A; IE870415L; NO870494L; DK81787D0; DK81787A; JPS62192321A; FI870657A0; DK174984B1; DE3779939D1; ES2041649T3; EP0238814A2

Abstract

ABSTRACT OF THE DISCLOSURE
The method of combating bacterial infection of fish which comprises supplying to such fish or to their water an antibacterially effective amount of a quinoline derivative, salt or hydrate thereof of the formula

Description

` `` ~302;~7~
Antibacterial Drugs for Fish This invention relates to antibacterial drugs for fish. More particularly, the invention relates to anti-bacterial drugs useful for the prevention, cure and treatment of infectious diseases of fishes cau~ed by microorganisms or aquatic microorganisms,..which contain as the effective ingre-dient the quinoline compounds, salts, or hydrates thereof represented by the general formula o F ~ ~ ~ COOR2 (I) Rl-N~_~N N

wherein Rl represents a hydrogen atom, a lower alkyl or lo~.~er hydroxy alkyl group, and R~ represents a hydrogen atom or a lower alkyl group~
Recently fish culturehas been more and more extensively carried on due to the problem of 200-miles' fishing 20ne and shortage in the f ishery resource caused by overfishing. Ac-companying this trend, efforts are being directed to high-efficiency fish production. Particularly in high-density cultivation fishery practiced with youn~ ye~lowtails, eels, or the like, mass attack of infectious diseases i~ the fish occur with high frequency, and if such diseases are left untreated, the damage occasionally amounts to entire destruction of the fish in the culture farm. Even if the damage does not extend so far, those fish that survive are spoiled and have markedly reduced Le A 24 680-CA
. _ ~3~27~

co~mercial value. This type of problem is encountered at many places, and its early and effective solution has been strongly in demandO
The majority of infectious diseases of fish are caused by ~icroorganisms or aquatic microorganisms, ~nd for their pre~ention sr cure heretofore it has been practiced to add antibacterial drugs such as sul~as, nitrofuran, synthesized penicillin, tetracycline, macrolide antibiotics, nalidixic acid, oxolinic acid, piromidic acid or chloroamphenicol to the ~eed for their oral ~dministration to fish, or ~o put infected fish in the water containin~ surh antibiotics as dissolved therein, so-called ~edicated bath, for a predeter~ined period.
However~ here~o~ore known antibacteri~l drugs as above-named have such de~ects as their anti~icrobial gpectra are narrow, curative effect is little, safety ~argins (margin between the effectiv~ dose and toxic dose) are narrow, undesirable side-effects occur and their use i8 uneconomical, and therefore are not quite ~atisfactory.
It is ~ound that the quino1ine derivatives, their salts, and hydrates thereof expressed by the foregoing general formula (I) exhibit excellent preventive and curative e~fects broadly against ~arious in~ectious disea~es of fi~h caused by ~icr~organisms and ~quatic ~icroorganisms, that they also are highly effective against resistant bacteria and complicati~ns, and furthermore that they have low toxicity, are safe and quick in metabolism.

Le A 24 680 -and are extre~ely uited for preventive and curative anti-bacterial drugs for infectious diseases of ~ish. Whereupon the present in~en~ion was completed.
Referring to aforesaid ~eneral for~ula (I), lower alkyl moieties in ~lower alkyl~ or ~lo~er hydroxy alkyl~ groups include ~traight chain or branched chain alkyl groups contain-ing up to 8iX carbon atoms, preferablY up to four carbon atoms, e.g., methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, tert-butyl, etc. And, preferred GpeCifiC examples of Rl include hydrogen atom, methyl, ethyl and ~ hydroxye~hyl groups. Also as R2~ hydrogen atom, methyl and ethyl groups are preferred.
Typical exampl~s of the quinoline derivatives of formula (I) to be used as the effective ingredient in the antibacterial drug of this invention include the following:
l-Cyclopropyl-6- luoro-1,4-dihydro-4-oxo-7-piperazino-quinoline-3-carboxylic acid, ~ethyl l-cyclopropyl-6-fluoro-154-dihydro ~-oxo-7-piperazino-quinoline-3-carboxylate, Ethyl l-cyclopropyl-6 fluoro-1,4-dihydro-4-oxo-7-piperazino-quinoline-3-carboxylate, l-Cyclopropyl-6-~luoro-1,4-dihydro-4-oxo-(4-methyl-piperazino)-quinoline-3-carboxylic acid, Ethyl l-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-methylpiperazino)4-quinoline-3-carboxylate, l-Cyclopropyl-6-fluoro1,4-dihydro-4 oxo-7-~4-ethyl-piperazino)-quinoline-3-carboxylic acid, Le A 24 68Q

.

~L30;~

Ethyl l-cyclopropyl~6i-fluoro-1,4-dihydro-4-oxo-7 (4-~thylpiperazino)-quinoline-3-carboxylate, and l-Cyclopropyl-6-fluoro-1,4-dihydrO-4-O~O-7-(47S-hydroxyethyl-piperazino)-quinoline-3-carboxylic acid.
The quinoline derivatives of ~ormula (I) may be used in the ~orm o~ acid addition ~alts utilizing ~he ~asicity of piperazino group at 7-position. Exampl~s of such aci~ addition salts include inorganic acid salts such as hydrochloride, hydrobromide, hydroiodide ~nd sulfate; and organic acid salts such as acetate, citrate, benzenesulfonate and embonate ~pamoate~.
Again, when R2 is a hydrogen atom, in the formula (I) quinoline derivatives the carboxyl group at 3-position may b~ in a salt ~orm. As such salt, alkali netal salts such as sodium salt or potassium 8alt; alkaline earth metal salts such as magnesium salt or calcium salt; and ammonium ~alt, etc., are included.
Furthermore, the quinoline derivatives of formula (I) or ~alts thereof may be used in the form of their hydrates~
~ ost of ~he quinoline derivatiYes of formula (I) are the compounds known ~ e, as disclosed~ for example, in Laid-Open Patent App}ications, Xokai Nos. 71683/82 and 74667/83, and can be prepared by ~he methods described in those Rokai gazettes.
For adminis~ering the ~uinoline derivatives, ~alts th~reof or hydrates thereof of formula ~I) [hereinafter they are referred to as ~active co~poundc o~ formula (I)~l to fish a~ antibac~erial drugs, they may be blended in ~he fish feed to be orally ad~ini~tered, or ~ay be dissolYed in water in which Le A 2~ 680 _ , , . ,~.
i ~30~27~L

sick fish are put and allowed to swim ~round (a method using so-called ~a r,ledicated bath").
And, ~he active compounds of formula (I) can be given the formulation form suitable for ~uch method of ~dministration, ~or example, powder, granul~ or solution as feed additives; or a soluble dispersant or solution for medicated bath. Methods for making such formulations ~ se are similar to those normally practiced for for~ulation of preventive and curative drugs for acute attack. In general practice one or ~ore of various additives, e.g., excipients such a-~ soybean protein, lactose, beer yeast and limestone; diluents 6UC~ as water; solubilizing agents such as benzyl alcohol, n-butanol~ etc.; thickener such as hydroxypropylmethyl cellulose; and pH-regula~ors uch as pota~sium hydroxide, sodium hydroxide, lactic acid, hydro-chloric acid and acetic acid, are suitably blended with the active compound of formula (I) to give the desired form of formulation. ~ereinafter the typical forms will be more specifically explained.

~; Active compound of formula (I) 1-10 parts by weight Soybean protein 99-90 Total 100 Soybean protein is added to the active compound of formula (I), and homogeneously mixed in ~ mi~er.

Le A 24 680 ~3~;~Z~

edicated bath):
Active compound of for~ula ~I) 0.5-10 parts by weight Po~assium hydroxide 0.08-l.S n Benzyl alcohol 1. 3-1~ 4 r Hydroxypropylmethyl cellulose 50 0-3.5 x ~urified water bnl~Ace Total 100 Potassium hydroxide is added to purif ied water and stirred until a homogeneous system is obtained, to which the active compound o~ formula (I), benzyl alcohol and hydroxy-propylmethyl cellulose 50 were added and stirred to uniformity.

Active compound of formula (I) 1-10 parts by weight (one that is water-soluble)' Lactose ~ 0 _ Total 100 Lactose is added to the active compound of formula (I), and hsmogeneously mixed in a mixer.
In the use of active co~pound of formula (I) as the antibacterial drug for fish, the administration dosage differs depending on the purpose of administration ~prevention or cure o~ disease) and type, size and extent of inf~ction of the object fish to be reated~ Normally, however, the dosage within 5-1000 mg, preferably 20-100 mg, per kg of body weight of fish ~ay be adminis~ered per day, either at one time or as divided i~to several times. Needless to explain, however, the above dosage is a rough standard, which may be reduced or increased depending on ~ge, body weigbt, condition of disease, Le A 24 680 L31D~227 etc. of the object ~ish. The term of administra~ion is not particularly limi~ed, but normally that for 1 - about 10 days can achieve ~ufficient effect.
The antibacterial drugs provided by pre~ent invention are broadly active against various ~icroorganisms and aquatic ~icroorgani~ms which induce infectious di~eases ~mong fish.
For example, the drugs exhibit powerful ~ntibacterial action ~gainst bac~eria belonging to ~ Aero~onas, 9~
Edwardsiella, 9~ Pasteurella, 9~ Pseudomonas genus Stre~tococcus and ~ Vibrio, and consequently are extremely ;
useful for prevention, cure and treatment of infectious diseases of cultiva~ed fresh-water and eawater fish such as young yellowtails, yellowtails, eels, ~yus, troutt s~.lLlon carps,etc.
and of aquarium fish such as goldish and tropical ~ish.
Such excellent activities of the antibacterial drugs of presenk invention are proven by the ~ollowing in vitro and in vivo tests in which ~he ~ollowing compounds were used.
Compound A: hydrochloride o~ l-cyclopropyl-6-fluoro-1, 4-dihydro-4-oxo-7-piperaz ino-~u inol ine-3 carboxylic acid Idecomposition point:
319-321C~
: Compound B: monohydrate of hydrochloride of l-cyclo-propyl-6-~luoro-1,4-dihydro-4-oxo-7-piperazino-quinoline-3-carboxylic acid Compound C: ~ydrochloride of l-cyclopropyl-6-fluoro-1, 4-dihydro-4-oxo-7- 1 ~-methylpiperaz ino) -quinoline-3-carboxylic acid t~ecomPosition Le A 24 680 point: 345-347S~

3~2;~79L

Compound D: 1 cyclopropyl-6 fluoro-1,4-dihydro-4-oxo 7-~4-ethylpiperazino)-guinoline-3-carboxylic acid Compound ~: dihydrate of hydrochloride of 1 cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-~thyl-piperazino~-quinoline-3 carboxylic acid Compound F: hydrochloride of l-cyclopropyl-6-fluoro-1~4-dihydro-4-oxo-7-(4-~-hydroxyethyl-piperazino~-quinoline-3-carboxylic acid (decomposition point: 327-333C) Co~pound G: embonate of l-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo 7-(4-e~hylpip~razino)-quinoline-3-carboxylic acid Compound H: ethyl l-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-ethylpiperazino)-quinoline-3-carboxylate (decomposition point: 187-189C) Compound O~ (control): l-ethyl~ -dihydro-6,7-~ethylene-dioxy-4-oYo-3-quinolinecarboxylic acid Test E~amp~le 1 In vitro antibacterial activity on pa~hogenic bacteria ~or fish Each of the test strains was cultured for an over~
night, and each culture broth (containing about 10~ cells/ml) was innoculated in Mueller-~inton agar ~DIFCO) added ~ith 1.0-2.0% ~odium chloride and containing the test co~pound at each ~pecified concentration. The ~inimum growth~inhibition concentra.ion (MIC) was d~termined ~or sach compound after 20 hours' incubation a~ 25-30C. The results were as ~own in Table 1 below.
Le A 24 680 ' ''' ' . , ~3~2274 g u~ n O ~o ~ o o o ;~ ol ~oc~oo oc~ o o~v v v v v _ ___ _ ~
o ~ ~ ~ ~ o u~ u~~ o u~ ~ O
= ~ > c~ c~ o ~ o o V ~ t.7 o o o ~ o :~ o ea O OO O O ~ C:~
~ ~~ ~ ~ o ~
a ~ . ~ O O O ~ ~ O
~: ~ ~ o o o C~ o o o o ~ o V V V V
~: o o o o ~
::>S O O O O O O O O D O V V V V
t~' ~ o o o o o o o C~

~9 ~ U'l e~ ~ O ~ O O O
,~ ~ o o o o o c~ O s~ ac:~ o o o o a~~ ~ c~ o o o o o o o o o o V V V V
t) ~ In ~ ID ~a u u u~
~a~ u~ O u~ o o o ~ o o o o c~ c~
~U ~ OOOOO VVVVV VVVVV
O t Ir) U'> ~
.C o o ~ ~ ~ ~ o o o o o c2 ooooo ooo o o v v v v v O O~ o~oo~
c O O c~ o o o o o c o' o o o o c, v v v v v v v v v v ~ v ~ _ __ _ _ . , ~ C ~o tO C ~Co CO Cl: C ~O ~ ~_ C CO C ~

Le A 24 680 _ ___ ~30;~:Z7~

In ~itro antibacterial activity of Co~pound D against Various Pathogenic Bacteria for Fish Each of the test strains was cultur~d ~or an over-night, and the resultan~ cul~ure broth (containing about 106 cells/ml) was innoculated in ~ueller-~inton agar (DIFCO) added ~ith 1.0-200% sodium chloride and containing ~he test compound at the sp~cified concentration. The mini~um growth-inhibition concentration (MIC) was determined for each compound after 20 hours~ incu~ation at 25-30C. The results were as shown in Table 2 below.

Le A 24 680 .. .
.

O S`~ i O O O
o ~ _, o o ~ o r~
n .r~ ~ o ~n O O~`3 ~ ~ ~ o ,, ~ o _l ~ O
_ _I o C~ O O O
o ~ o . o Q. ~ O ~ o ~ ~ _ ~q U~
~1 ~ ~ u~
o ~ ~ o _, ~ O o _, ~
..... ..
~1 ~I ~ C~ O O C~0 0 0 0 ~ o :~ I I I ~I . I I
r~ ~ OU~ O
~ ~ ~ ~ ~ ~ O ~
" ~a ~_l _, o_~ _l o o o ~ ~ o t~ ~ ~ ~ o . , ~U O O O o V V V
~ u _ .
.r~ m 'q 1.~ 4 C
~IJ U a ~1 J-~ ~ ~ u~ 70 ) ~ U~
~ C E3 1~ ~V
~ ~ æ o ~o .rl O ~ .
~ ~: _ _ __~__ ..
C~
o V
L~

Cl~ Il~ _I
~ ~Cr~ ~.~ .~~ ~.
~ D~ e ~
~ o o fl~ q ~o .. ~ h EE ~''I ~ --.~
al ~ ~ :' ~'~ '' ~ D .C ~ ~
_, _I_I a~.) ~~ .,, .9 J U~ C3 ~-I
lo o~ s~ o~ o E l ~U c e~ O -~
E~ O O ~~:1 0J.l O
O O ~ 1 ~ ~J ~tO
a~

Le A 24 680 gL3022~L
~, . ~

Of those active compounds used in the above test examples, a production example of compound H is shown here-inbelow for reference.
Production Example 1 Into a suspension o~ 18 g of 1-cyclopropyl-7-(4-ethyl-l-piperazinyl)-6-fluoro-1,4-dihydro-4-oxo~quinoline-3-carboxylic acid in 120 ml of ethanol, 24 g of 96% conc. sul-furic acid was added dropwise. The resulting mixture was refluxed for 12 hours, and after removing excessive alcohol under a reduced pressure, the remainder was dissolved in 200 ml of ice water. Under cooling with ice, the pH of the system was rendered 12-14 by addition of a cold solution of 19.2 g of sodium hydroxide in 100 ml of water, and the precipitate formed in the meantime was suction-filtered. The precipitate was then washed with water and dried at lOO~C under a reduced pressure.
Upon recrystallizing the same from tolueneJlight benzene, 10 g of ethyl ester of l-cyclopropyl-7-~4-ethyl-1-piperazinyl)-6-fluoro-1,4-dihydro-4~oxo-quinoline-3-carboxylic acid (52.5% of the theoretical amount) melting at 187-189C was obtained.

!

Le A 24_680

Claims

1. The use for combating bacterial infection of fish of an antibacterially effective amount of a quinoline compound, salt or hydrate thereof of the formula in which R1 is hydrogen or a lower alkyl or lower hydroxy alkyl group, and R2 is hydrogen or a lower alkyl group.

2. A use according to claim 1, wherein such compound is 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-piperazino-quinoline-3-carboxylic acid, or a salt or hydrate thereof.

3. A use according to claim 1, wherein such compound is methyl-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-piperazino-quinoline-3-carboxylate, or a salt or hydrate thereof.

4. A use according to claim 1, wherein such compound is ethyl-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-piperazino-quinoline-3-carboxylate, or a salt or hydrate thereof.

5. A use according to claim 1, wherein such compound is 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo(4-methyl-piperazino) -quinoline-3-carboxylic acid, or a salt or hydrate thereof.

6. A use according to claim 1, wherein such compound is ethyl-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-methyl-piperazino)-4-quinoline-3-carboxylic acid, or a salt or hydrate thereof.

7. A use according to claim 1, wherein such compound is 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-ethyl-piperazino) -quinoline-3-carboxylic acid, or a salt or hydrate thereof.

8. A use according to claim 1, wherein such compound is ethyl-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-ethylpiperazino)-quinoline-3-carboxylate, or a salt or hydrate thereof.

9. A use according to claim 1, wherein such compound is 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-.beta.-hydroxyethyl-piperazino)-quinoline-3-carboxylic acid, or a salt or hydrate thereof.

10. A fish feed composition which comprises a fish feed and admixed therewith, an antibacterial quinoline compound, salt or hydrate thereof of the formula (I) in which R1 is hydrogen or a lower alkyl or lower hydroxy alkyl group, and R2 is hydrogen or a lower alkyl group.

11. A composition according to claim 10 wherein the compound is 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-piperazino-quinoline-3-carboxylic acid, or a salt or hydrate thereof.

12. A composition according to claim 10 wherein the compound is methyl-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-piperazino-quinoline 3-carboxylate, or a salt or hydrate thereof.

13. A composition according to claim 10 wherein the compound is ethyl-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-piperazino-quinoline-3-carboxylate, or a salt or hydrate thereof.

14. A composition according to claim 10 wherein the compound is 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-(4-methyl-piperazino)-quinoline-3-carboxylic acid, or a salt or hydrate thereof.

15. A composition according to claim 10 wherein the compound is ethyl-l-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-methylpiperazino)-4-quinoline-3-carboxylate, or a salt or hydrate thereof.

16. A composition according to claim 10 wherein the compound is 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-ethyl-piperazino)-quinoline-3-carboxylic acid, or a salt or hydrate thereof.

17. A composition according to claim 10 wherein the compound is ethyl-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-ethylpiperazino)-quinoline-3-carboxylate, or a salt or hydrate thereof.

18. A composition according to claim 10 wherein the compound is 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-.beta.-hydroxyethyl-piperazino)-quinoline-3-carboxylic acid or a salt or hydrate thereof.

19. A medicated bath for use in treatment of infected fish, which bath contains water and an antibacterially effective amount of a quinoline compound, salt or hydrate thereof of the formula (I) in which R1 is hydrogen or a lower alkyl or lower hydroxy alkyl group, and R2 is hydrogen or a lower alkyl group.

20. A bath according to claim 19 wherein the compound is 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-piperazino-quinoline-3-carboxylic acid, or a salt or hydrate thereof.

21. A bath according to claim 19 wherein the compound is methyl-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-piperazino-quinoline-3-carboxylate, or a salt or hydrate thereof.

22. A bath according to claim 19 wherein the compound is ethyl-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-piperazino-quinoline-3-carboxylate, or a salt or hydrate thereof.

23. A bath according to claim 19 wherein the compound is 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-(4-methyl-piperazino)-quinoline-3-carboxylic acid, or a salt or hydrate thereof.

24. A bath according to claim 19 wherein the compound is ethyl-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-methylpiperazino)-4-quinoline-3-carboxylate, or a salt or hydrate thereof.

25. A bath according to claim 19 wherein the compound is 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-ethyl-piperazino)-quinoline-3-carboxylic acid, or a salt or hydrate thereof.

26. A bath according to claim 19 wherein the compound is ethyl-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-ethylpiperazino)-quinoline-3-carboxylate, or a salt or hydrate thereof.

27. A bath according to claim 19 wherein the compound is 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-.beta.-hydroxy-ethyl-piperazino)-quinoline-3-carboxylic acid, or a salt or hydrate thereof.