CS195713B2 - Method of producing novel aminoglycosides of 2-deoxystreptamine - Google Patents

Description

(54) A process for the preparation of the novel amphoglycosides of 2-dsoxystreptamine

The present invention relates to antibacterial agents and in particular to a group of novel 2-deoxystreptamine aminoglycosides which are antibacterially active, as well as to a process for the preparation thereof.

In MS. No. 195,712 discloses novel compounds of formula X cw / wr '

OR ¹ *

OH 1

7XJ in which

R ¹ represents a hydrogen atom or a lower alkyl group,

R ² is amino or hydroxyl, one of R ³ and R ⁴ is hydrogen and the other of the symbols represents the below-defined glycosyl group and n is 1, 2 or 3, and their pharmaceutically acceptable acid addition salts.

When R ^{4 is a} glycosyl group, it may be the only hexopyranosyl group preferably containing an amino group, such as the 3-amino-3-deoxy-α-D-glycopyranosyl group found in kanamycin A and B. If R ^{3 is a} glycosyl group group, this group is generally a pentofuranosyl group, optionally linked to another hexopyranosyl group by another glycosidic bond. For example, R ³ may represent a β-D-ribofuranosyl group as found in ribostamycin.

The term "lower alkyl" refers to a group having from 1 to 4 carbon atoms, straight or branched.

The present invention provides a process for the preparation of the novel 2-deoxystreptamine aminoglycosides of formula (I)

Ηθ ~ ζ ~ ° \ θ \

OH

NHCH 2 CH (CH 2 NH _X

HO OHHO OR ¹ * (I) in which ·

R ⁴ represents a 3-amino-3-deoxy-α-D-glycopyranosyl group and n is 4, 5 or 6; and their farm195713

4 a pharmaceutically acceptable acid addition salt, characterized in that the compound of formula II is used

CHNH, NH.

pg ^K pL 0 OH

NH-C-CH (CH ₂ ) 2. ₁ -X NM,

HO OHHOR * (ID in which

R ⁴ and n are as defined above and

X is CH 2 or CO, subjected to reduction, and the compound of formula I obtained is isolated and / or optionally converted to its acid addition salt.

The reduction of the keto or keto groups in the starting materials of formula II is carried out in a manner known per se, preferably using diborane.

Pharmaceutically useful acid addition salts of the compounds of the invention are those formed with acids resulting in non-toxic acid addition salts containing pharmaceutically acceptable anions, for example, hydrochlorides, hydrobromides, hydroiodides, sulfates or bisulfates, phosphates or acid phosphates, acetates, maleates, fumarates, lactates, tartrates, citrates, gluconates, p-toluenesulfonates and salts with carbonic acid.

Numerous compounds of formula (II) are known and previously described. For example, 1-N- (6-amino-2-hydroxyhexanoyl) kanamycin A is described in J. Antibiotics, 1974, 27, 851. Other compounds may be prepared by procedures analogous to those described herein.

In the novel compounds of the invention, both rings are generally in a "chair" conformation and all substituents have an equatorial position relative to the ring. Further, the glycosidic bond between the hexopyranosyl ring and the 2-deoxystreptamine ring is most commonly α-bonded to the first of said rings, especially when the compounds of formula (I) are used. II derive from the natural amlnoglycosides of 2-deoxystreptamine. The β-hydroxy-ω-aminoalkyl group on N ¹ may further exist in the S or R configuration or as a mixture of both optical isomers.

Evaluation of Antibacterial Efficacy of the Compounds of the Invention In vitro is performed by determining the minimum inhibitory concentration of the test compound in a suitable environment without growth of the test microorganism. In practice, agar plates with the addition of test compound at the appropriate concentration are inoculated with a standard number of cells of the test microorganism and each plate is then incubated at 37 ° C for 24 hours. It is then determined whether or not the test plates have occurred. no growth of bacteria has occurred and the appropriate minimum inhibitory concentration values are determined. Microorganisms used in these assays include strains of Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aerugiosa, Staphylococcus aureus, and Streptococcus faecalis.

In vivo assays are performed by administering test compounds subcutaneously to mice exposed to Escherichia coli infection. Each of the test compounds is administered in a series of different doses to groups of mice and its efficacy is expressed as providing 50% protection against the lethal effect of Escherichia coli within 72 hours.

For use in human medicine, the antibacterially active compounds of the invention may be administered alone, but are generally administered in admixture with a pharmaceutically acceptable carrier selected with respect to the intended route of administration and standard pharmaceutical practice. For example, the compounds may be administered orally in the form of tablets containing, for example, starch or lactose as the carrier, or in the form of capsules containing either the active ingredients alone or mixtures thereof with carriers and excipients, or elixirs or suspensions containing flavorings; dyes. The active compounds may also be administered by parenteral, for example intravenous, intramuscular or subcutaneous injection. For parenteral administration, the active compounds according to the invention are most preferably used in the form of sterile aqueous solutions which may contain other soluble substances, for example, an appropriate amount of salts or glucose, in order to render the solution isotonic.

_T is expected that the application in human medicine will be antibacterially active compounds of the invention may be administered in daily doses comparable to aminoglykosidickými antibacterial agents used in present practice, for example in doses of from 0.1 to 50 mg / kg (in divided doses) when applied parenterally or at doses of 10 to 100 mg / kg (in divided doses) when administered orally. Thus, it is expected that tablets or capsules for oral administration up to four times a day will contain from 0.1 to 1 g of active ingredient, while unit doses for parenteral administration will contain from 10 to 500 mg of active ingredient.

It will be within the skill of the physician to determine the appropriate dose which will be most suitable for the patient and which will vary depending on the patient's age, weight and response to the preparation administered. The above dosages are exemplary dosages for the average patient. Of course, there may be individual instances where higher or lower dosages will be required, and these are also within the scope of the invention.

The invention is illustrated by the following non-limiting example. All temperatures in this example are given in degrees Celsius.

Example

1.0 g (1.36 mmol) of N - [(S-2-hydroxy-6-aminohexanoyl) kanamycin A dicarbonate is dissolved in 10 ml of anhydrous trifluoroacetic acid and the solution is evaporated to dryness in vacuo. of dry nitrogen is added 75 ml

M solution of dlborane in tetrahydrofuran and the resulting solution was heated at 50-55 ° C for 5 hours. Evaporation of the organic solvent under reduced pressure gave a gummy residue which was taken up in 10 ml

N hydrochloric acid. After 10 minutes, the solution was basified with 5 N sodium hydroxide solution to pH 10 and finally acidified with 2 N hydrochloric acid to pH

6. The resulting solution is chromatographed on an ion exchange column (Sephadex CM-25) in an NH 4 ⁺ cycle (3.5 x 90 cm). The column was eluted with water and an ammonium hydroxide solution having an increasing ammonium hydroxide concentration of from 0 to 0.6N. Fractions containing the desired product after thin layer chromatography were combined and evaporated in vacuo. 0.64 g (63%) of N - [(S) -2-hydroxy-6-aminohexyl] kanamycin A is obtained. Thin-layer electrophoresis

The product has an _{Rf of} 0.85. A mixture of equal parts of acetic acid and formic acid at pH 2 is used as the electrolyte and a voltage difference of 900 V is applied to the opposite ends of the silica gel coated plates (length 20 cm) for 45 minutes. Detection is accomplished by drying the plate, spraying with a cyclohexane solution of tert-butyl hypochlorite, then drying and developing upon cooling with a solution of starch and potassium iodide. Under these conditions, the starting material R _f = 1.0. Mass spectrometry

A sample of the product was converted to a volatile penta-N-acetyl-octa-O-trimethylsilyl derivative by reaction with acetic anhydride in methanol at room temperature for 24 hours, followed by reaction with hexamethyldisilazane and trimethylchlorosilane (2: 1) at room temperature for 24 hours.

For C58H123N5O17Si8 calculated: m / e 1385 found: m / e 1385.

The results of the in vitro antibacterial activity assays of the compounds of the previous examples, using the methods described above, are summarized in the following overview:

In vitro potency of minimum inhibitory concentration in µg / ml

Escherichia Klebsiella Proteus Pseudomonas Staphylococcus eoli pneumoniae mirabilis aeruginosa aureus

6.2 6.2 3.1

3,1 1,6

From the foregoing, it is understood that the invention includes the novel aminoglycosides of 2-deoxystreptamine of formula (I) and a process for their preparation, pharmaceutical compositions containing the novel aminoglycosides of formula (I) or pharmaceutically acceptable acid addition salts thereof, and a method of treatment infections of animals, including humans, caused by Gram-positive and Gram-negative bacteria, consisting in the administration of therapeutic doses of the novel aminoglycosides of general formula (I).

SUBJECT

Claims (4)

A process for the preparation of the novel 2-deoxystreptamine aminoglycosides of the general formula I in which R ⁴ and n are as defined above and X is CH 2 or CO, is reduced and the compound of formula I obtained is isolated and / or optionally converted to its acid addition salt. 2. A process according to claim 1, for the preparation of compounds of formula I in which R ' ⁴ is as in lan and has a value of 4 and pharmaceutically acceptable acid addition salts thereof, characterized in that the compounds of the formula I are used as starting materials. of formula II wherein R ⁴ and X have in which R ⁴ represents a 3-amino-3-deoxy-α-D-glycopyranosyl group and n is 4, 5 or 6, and their pharmaceutically acceptable acid addition salts, characterized in that the compound of the formula Π 0 OH C-CH 2 CH 2 .F-XN 4 (II) is as in 1 and n is as defined in this point. 3. A process according to claim 1, for the preparation of compounds of the general formula Ϊ in which R ^{@ 4 has the} meaning as in point 1 and n having a value of 5 or 6, and pharmaceutically acceptable acid addition salts thereof, characterized in that starting materials are used. the compounds of formula (11) wherein R ⁴ and X are as in 1 and n are as defined herein. 4. The process of claims 1 to 3, wherein the reduction is carried out with dlborane.