DK175198B1 - Antibiotic, designated gallidermin, and acid addition salt thereof, pharmaceutical and cosmetic preparations containing compounds and procedure for production of the compounds as well as their use in production of a pharmaceutical preparation - Google Patents

Abstract

An antibiotic, designated gallidermin, with the formula:<IMAGE>and pharmaceutically acceptable acid addition salt thereof. The compounds are usable in treatment of bacterial infections, notably skin infections, and also usable in cosmetic, notably collagen-containing, preparations. Gallidermin can be produced through cultivation of a gallidermin-producing strain of Staphylococcus gallinarum.

Description

in DK 175198 B1

The present invention relates to a novel antibiotic, termed gallidermine, salts thereof, pharmaceutical compositions containing the compounds and methods of the preparation of the compounds, and their use in the preparation of a pharmaceutical composition.

A number of polycyclic peptide antibiotics are known. Some of these antibiotics contain a lanthionine structure such as nisin, subtilin, duramycin, cinnamycin, ancovenin, Ro 09-0198, pep5 and epidermin.

Typically, these antibiotics have a high content of unsaturated amino acids (dehydroalanine, dehydrobutyrin) and thioether amino acids {meso-lanthionine, (2S, 3S, 6R) -15-methyl-methylthionine). Lysinolanine, 3-hydroxyaspartic acid and S- (2-aminovinyl) -D-cysteine have also been found in some of them.

Apart from structural similarities between duramycin and cinnamycin, there appears to be little sequence homology between these various known pep-time antibiotics. This can be seen clearly in FIG. 1, showing the propeptide sequences for said antibiotics. For example, this figure clearly shows that epidermin does not show any significant sequence homology with the other antibiotics.

Furthermore, it should be noted that the origin of the epidermis differs from the origin of the other antibiotics (except pep5), the epidermin being obtained by cultivating one strain of the microorganism Staphylococcus 30 epidermis while the other antibiotics being obtained by cultivating strains of Streptococcus lactis (nisin),

Bacillus subtilis (subtilin), Streptomyces cinnamo-nose and Streptomyces sp. (cinnamycin, duramycin and

I DK 175198 B1 I

i 2 I

In ancovenin) and Streptoverticillum griseoverticillum

I (Ro 09-0198). IN

Epidermin is particularly active against microorganisms

In the niche Propionibacterium aenes and has consequently been I

I 5 investigated as a possible therapeutic active substance for I

In use in the treatment of acne. IN

However, it has now been found that a peptide, I

Structurally closely related to epidermin, you have

In a surprisingly larger activity towards Propioni I

In 10 bacteria is compared with epidermin. When the I

In known peptide antibiotics in general, I differ significantly

In structural terms, it was unexpected,

In the presence of another such antibiotic,

If you differ only from one of the said antibiotics at I

In 15 changes of one amino acid and it was another I

In surprising and unpredictable, such a replacement- I

The formation of a single amino acid in the epidermin would lead I

I to a significant increase in activity against micro I

In the organism Propionibacterium aenes. IN

The present invention thus provides

A compound, called gallidermine, is led with I

In the structure I

In CH? -S-CHo I

I i 1 I

In H-Ile-Ala-NH-CH-CO-Lys-Phe-Leu-NH'CH-CO-NH-I

I -D- -L- I

I 25 'I

f1 I

I -CH-s-ch2 I

I I I I

I CH-CO-Pro-Gly-NH-CH-CO-Ala-Lys-Dhb-Gly-I

I -0- -L- I

I 30 I

In cm2-s-CH2 I

I -NH-CH-CO-Phe-Asn-NH-CH-CO-Tyr-NH-CH-CO-NH-CH I

I t 11 I

I I1 I

ch2-s - ch I

And pharmaceutically acceptable acid addition salts thereof.

Gallidertine can be produced by culturing the microorganism Staphylococcus gallinarum (F1S / P57) Tu 5 3928, which, under the Budapest Treaty, was deposited with the Deutsche Sammlung von Microorganism on May 18, 1988 and obtained serial number DSM 4616, or mutants thereof.

Staphylococcus gallinarum (F16 / P57) Tu 3928 10 (DSM 4616) belongs to a recently discovered Staphylococcus species described by Devriese et al. (Int. J.

Syst. Bacteriol. 334-486 (1983)). The strains can be isolated from chicken combs.

Stems S. gallinarum (F16 / P57) Τϋ3928 (DSM

15 4616) is described in detail in the article by Devriese et al. discussed above.

It should be noted that the DNA / DNA homology between S. gallinarum and S. epidermis is only between 10 and 25%, indicating that gallidermin and epidermin-producing strains belong to distinctly distinct species. It should also be noted that the two species differ by several other markers, such as the novobiocin resistance and the wide range of positive hydrocarbon hydrolysis (cellobiose, mannitol, melezitose, trehalose, arabinose, ribose and xylitol) by S. gallinarum (Arch. Microbiol. 92, 65-85 (1973), J. Clin.

Microbiol. I, 82-88, (1975), and "The Procaryotes",

Springer Verlag, Heidelberg, 1548-1569 (1981)).

Accordingly, the present invention provides a further process for the preparation of gallidermin and pharmaceutically acceptable salts thereof, which method involves culturing a microorganism capable of expressing gallidermin, preferably

I DK 175198 B1 I

I 4 I

In some S. gallidermin (F16 / P57) Tu 3928 (DSM 4616), un- I

In conditions under which gallidermin is expressed

I and secreted into the culture medium and, if desired, transformed

Providing the isolated substance to a pharmaceutical ac-

In acceptable salt thereof. IN

In The cultivation of gallidermin-producing microor- I

In ganisms such as S. gallidermin (F16 / P57) Tu 3928 (DSM I

I 4616), can be carried out by standard methods during use

In view of conventional culture medium. For example, you can

In 10 S. gallidermine (F16 / P57) Τύ 3928 (DSM 4616) is grown in I

In a medium containing a suitable nitrogen source, I

In suitable carbon source and a hydroxide of an alkaline earth I

In metal, for example, a medium containing meat

In extract, malt extract and Ca (OH) 2 in a suitable bio-I

In reactor. Cultivation must take place during aeration and before I

I for a pH range of e.g. 5.4-8.5, cultivation I

Preferably, a pH is started in the range 6-7. IN

I Gallidermin can be isolated from fermentation tissue

In any conventional manner that you

20 is used to isolate small molecule I proteins

By weight from such media. IN

In particular, it has been found that gallidermin readily I

You can be isolated by simply treating the culture media

In diet with an adsorbent followed by a pro- I

In 25 ces, comprising adsorption on a weak cation exchanger I

In resin, desalination and optionally an additional chro- I

In the mathematical purification step, e.g. reverse phase HPLC or I

I clay chromatography on Gel Sephadex LH20 using I

In the case of e.g. methanol / 0.01 N HCl (9: 1) as eluent

In ring medium. IN

Since the compound gallidermine is highly basic, I

You will readily form acid addition salts with suitable dyes

In pharmaceutically acceptable acids by conventional preparations

5 DK 175198 B1 methods. Physiologically acceptable organic or inorganic acids which may be used for this purpose are, for example, hydrochloric, hydrobromic, sulfuric, benzosulfonic, methanesulfonic, p-toluenesulfonic and cyclohexylsulfamic acids.

Antibacterial activity

Minimum inhibitory concentrations (MIC, Table I) were determined in liquid BF medium of the following composition: sodium lactate 0.5%, sodium sulfate 0.5%, potassium dihydrophosphate 0.05%, dicalcium hydrophosphate 0.15%, magnesium chloride 0.02%, ammonium chloride 0.05%, glucose 1%, supplemented (per ml) with Ca-15 pantothenate 50 µg, folic acid 0.25 µ9, niacin 50 µg, p-aminobenzoic acid 25 µg, pyridoxal hydrochloride 50 μ <3 and riboflavin 25 μg.

I DK 175198 B1 I

I 6 I

The results are shown in Table I below

In Table I I

Microorganisms MIC (ptg / ml) I

I St.aureus SG 511 4 I

I St. Aureus E 88 8 I

I St.epidermidis ATCC 12228 4 I

I 10 St. pneumoniae ATCC 6302 4 I

I Sc.pyogenes ATCC 8668 1 I

I Sc.faecalis ATCC 29212 64 I

I Cb.xerosis ATCC 9755 1 I

I E.coli ATCC 11775 128 I

I 15 Ps. aeruginosa BC 19 128 I

In Mc.luteus ATCC 9341 0.25 I

I Mc.luteus 15957 0.5 I

I Bac.fragilis (Bonn) 128 I

I Bac.fragilis (Koln) 128 I

I 20 Peptostreptococcus anaerobicus 0.5 I

In a comparative study with epids- I

In min on Propionibacterium aenes foals were obtained

In reverse MIC values: I

I MIC (µg / ml) I

In Gallidermin 0.125 I

Epidermin 0.25 I

Because of the broad spectrum antibacterial

In activity, gallidermin and its acid addition salts are I

Useful for controlling bacteria and for treating I

In the act of bacterial infections. In particular, gallids- I

In mine and its acid addition salts, because of their ac-

7 DK 175198 B1 activity against important strains of Propionibacterium aenes, particularly useful for combating skin infection such as aene, eczema, impetigo and cellulitis.

According to a further embodiment of the invention, there are thus provided pharmaceutical compositions containing as active ingredient gallidermine or a pharmaceutically acceptable acid addition salt thereof in combination with one or more inert pharmaceutical carriers and / or excipients.

For pharmaceutical use, said polypeptide can be incorporated into preparations in either liquid or solid forms using carriers and excipients conventionally used in the pharmacy, optionally in combination with additional active ingredients. For example, the composition may be used orally, parenterally, enterally or preferably topically. Preferred forms include, for example, solutions, emulsions, gels, spray products, lotions, ointments, creams or powders.

Advantageously, the compositions may be provided as dosage units, each unit being intended to deliver a fixed dose of active ingredient. The total daily dose can be varied according to the recipient and the disease being treated.

According to a further embodiment, the invention relates to the use of a compound of the invention for the preparation of a pharmaceutical composition, preferably for topical use, for the treatment of a bacterial infection, in particular skin infections such as eczema, impetigo, cellulitis and acne.

Gallidermine and its acid addition salts can also be used as additives in cosmetic preparations, especially those containing collagen in which they will - -— i_. - -

I DK 175198 B1 I

I I

You act as a stabilizer. IN

A cosmetic composition of the present invention

The invention will contain gallidermin or an acid I

dithion salts thereof in combination with a suitable carrier I

In and / or excipient, preferably collagen, and optionally

In other additives suitable for cosmetic

In preparations such as perfumes and dyes. IN

The invention is further described by the following I

In examples. IN

I 10 I

In Example 1 I

I Fermentation I

Frozen cultures of S. gallinarum were used

15 to inoculate agar plates containing GA medium. IN

After the inoculated plates were kept 12 hours at 1

37 ° C, they were transferred to Erlenmeyer flasks containing I

containing 100 ml of a culture medium consisting of 3.3% I

In meat extract, 3.0% malt extract and 0.38% Ca (OH) 2 at pH I

I 6.5. IN

The inoculated flasks were held on a rotary shaker I

(type RC106, Infors AG Basel) at a speed of 160 I

rpm and a temperature of 36 ° C for 8 hours. Of the result

pre-culture pre-culture 200 ml was used to inoculate an I

In 25-liter bioreactor fermentation vessel (Giovanola I

Freres, Monthey) equipped with an intensor system. The ten

the medium used was the same as in the previous one

In the sections described, but containing an additional 6%

NaCl. The rates of aeration and stirring were set

30 at 0.4 vol / vol / min. and 900 rpm. p02 of trains hur- I

In close to less than 10% over the first 5 hours. IN

After 10 hours, it increased to 80% over the remaining I

During running fermentation time. The pH dropped from 6.5 to 1

9 DK 175198 B1 5.4 during the first 8 hours and then increased to 8.5 during the remaining fermentation time. The maximum cell density was reached after 24 hours at 8-9 x 10 9 cells per cell. ml. The development of foam was reduced by repeated additions of Polyurax Polyol PPG2025 (BP Chemicals).

Insulation

After 34 hours of fermentation, adsorption resin Amberlite XAD-1180 was added directly to the fermentation vessel. Three batches of adsorbent (in amounts of 2%, 1% and 1% relative to the volume of the fermentation liquid) were added at 45 minute intervals. The resin was filtered off and washed with 15 liters of water and methanol / 0.01 N HCl (9: 1), and the active eluent (1.4 liters) was concentrated at reduced pressure to give a dry weight of 2.7 g.

The product was then redissolved in methanol / 0.01 N HCl (9: 1) and transferred to Amberlite IRC-50 (H + form) at pH 5.5. The resin was then washed with water and eluted with 0.1 N HCl.

The eluate containing gallidermin was then contacted with Amberlite XAD-1180 for desalination and the solution was separated from Amberlite and subjected to lyophilization.

The lyophilized product was then dissolved in water and chromatographed by reverse phase HPLC. This step was carried out on the Waters system with two pumps 501, an auto-injector WISP 712 and a gradient programmer M6B0. As stationary phases, Nucleosil 10C18 or 5C18 (columns 4.6x250 mm and 8x250 mm) and HD-Gel-RP-7s-300 (column 4x150 mm) were used.

I DK 175198 B1 I

I I

Elution was carried out using various I

In gradients of acetonitrile / 0.1% trifluoroacetic acid in I

In water. The resulting eluate containing gallidermin I

I was collected and concentrated by evaporation I

In 5 and, if desired, it is taken up in water and lyophilized several

In the hallways. IN

In the lyophilized product derived from desalted I

The purification step can be purified by gel chromatography as one

In alternative to RP-HPLC. In such an operation I

In Figure 10, the lyophilisate in methanol / 0.01 N HCl (9: 1) is seen and I is passed

I through a column using Sephadex LH 20 I

In the stationary phase. The resulting eluate contained

In the same gallidermin is treated as described above. IN

I The preparation of gallidermin by fermentation, I

For example, as described above, may be followed,

The standard test strain Micrococcus luteus I is used

In ATCC 9341 on agar plates containing 10 ml of GA agar I

Containing peptine 10 g, lab lemco powder (Oxoid) 8 I

In 20 g, NaCl 3 g, Na 2 HPO 4 2 g, glucose 10 g (sterilized I

In separate), agar 20 g, H2 O 1 liter, pH 7.2-7.4. IN

In the Strain S. gallinarum can be stored at -18 C in I

In tubes in the following medium: lab lemco powder (Oxoid) 33 g, 1 l

In malt extract (Franksel + Ech) 30 g, Ca (OH) 2 3.7 g, I

In glycerol 400 g, H 2 O 1 liter at pH 6.0. IN

Example 2 I

I Think

In 100 g Tincture contains H

In Gallidermine 1.0 g of H

In Ethanol (94.5 vol%) 56.0 g

In 1,2-Propylene glycol 40.0 g I

In demineralized water 3.0 g I

11 DK 175198 B1

manufacturing

Gallidermine is dissolved in a mixture of ethanol / 1,2-propylene glycol / water and the solution is then sterilized.

Example 3

Lotion 10 100 g Lotion contains

Gallidermine 1.00 g of 1,2-propylene glycol 7.00 g

Alkyldimethylbenzylammonium chloride (Benzalkon A®) 0.15 g Sorbitan monopalmitate (Span 40®) 0.40 g

Sorbimacrogol palmitate (Tween 40®) 1.20 g

Decyl oleate (Cetiol V®) 2.40 g Mix of cetyl and stearyl alcohols (Lanette 0®) 1.60 g

Cetyl palmitate 0.80 g

Demineralized water to 100 g 25

manufacturing

The above amounts of alkyl dimethylbenzylammonium chloride, sorbitan monopalmitate, sorbimacrogol palmitate, decyl oleate, cetyl and stearyl alcohols and cetyl palmitate are stirred in 75 ml of water, the filtered solution of gallidermine and 1,2-propylene resin water is stirred and the mixture is homogenized.

I DK 175198 B1 I

I 12 1

In Example 4 I

I Gel I

In 100 g of Gel I contain

I Gallidermine 1.0 g I

In polyethylene glycol ether of I

In lauryl-al alcohol (Brij 35 ®) 1.0 g I

I 1,2-Propylene Glycol 5.0 g I

In Acrylic Acid Polymer (Carbopol I

I 9 934®) 1.2 g I

In methyl p-hydroxybenzoate 1.6 g

In propyl p-hydroxybenzoate 0.4 g I

In Perfume g.s. IN

In sodium hydroxide solution to pH 6.5 I

In 15 demineralized water to 100 g I

In Manufacture

The amounts of excipient listed are stirred in 75 ml of I

In water. Gallidermine is dissolved in a mixture of 1.2-I

In 20 propylene glycol and the remaining water and this dissolves

In solution, stir in. The finished gel is homogenized again. IN

In Reference Example 1 I

I 25 By thin layer chromatography on silica gel plates I

In 60F254 (Merck Darmstadt), the following Rf values were found

I for gallidermine: I

In Rf (chloroform / methanol / 17% NH 3 2: 2: 1) = 0.73 I

I Rf (chloroform / methanol / 17% NH 3 70:35:10) = 0.30 I

In 30 Rf (1-butanol / acetic acid / water 4: 1: 1) = 0.05. IN

13 DK 175198 B1

Reference Example 2

Total hydrolysis of the peptide (100 nmol) was carried out in 6 N HCl (200 μΐ) containing thioglycolic acid 5 (5 μΐ) under nitrogen at 110 ° C for 18 hours in sealed vials. After evaporation, the remaining hydrolyzate was dissolved in sodium citrate buffer pH 2.2 and analyzed using the standard program for the amino acid analyzer LKS 4150. The following 10 values were found (calculated):

Ala 1.98 (2), Asp 0.98 (1), Gly2.10 (2), Ile 0.92 (1), Leu 0.98 (1), Lan 2.0 (2), Lys 1, 91 (2), MeLan 1.0 (1), Phe 1.86 (2), Pro 0.91 (1), Tyr 0.87 (1).

Reference Example 3

Determination of amino acid configuration

The configuration of the protein amino acids and! in particular of lanthionine and 3-methylanthionine were determined by a recently developed gas chromatographic method (Kusters E. et al., Chromatographia, 18, 287-293 (1984)) which separates trifluoroacetylated amino acid n-propyl esters on glass capillaries (25-33 m) coated with Chirasil-Val (Frank H. et al., J. Chromatographia, 25 146, 197-206 (1978)) using a gas chromatograph Sichromat Auto derivative 100 (Siemens). Samples containing approx. 100 nmol of amino acids were derivatized as follows: esterification with 4 N HCl / 1-propanol (1 ml) at 110 ° C for 30 minutes in a sealed vial. After drying in a stream of nitrogen, trifluoroacetic anhydride (50 μΐ) was added and heated in the sealed medicine bottle at 140 ° C for 10 minutes. The solution was again dissolved.

I DK 175198 B1 I

I I

In the steamed in a stream of nitrogen. For analysis, samples I

Placed in dichloromethane. The carrier gas was nitrogen and I

A flame ionization detector was used. With them

In view of the temperature program, see the above reference I

In 5 cer. The following values were obtained:

I L-Ala (2), L-Asp (1), L-Gly (2), L-Ile (1), me

I so-Lan (2>, L-Leu (1), L-Lys (2), (2S, 3S, 6R) -3- I

In MeLan (1), L-Phe (2), L-Pro (1). IN

Reference Example 4 I

Tryptic cleavage

In Gallidermin was dissolved in a buffer solution (1 L

I mg / ml) consisting of 0.05 M N-ethylmorpholine acetate, I

In 0.01 M CaCl2.6H2O, pH 7.8 and trypsin (50 µg Calbio-I

In Chem). After 24 hours at 37 ° C, the enzymatic I

In cleavage stopped by the addition of acetic acid to pH I

I 4, and the solution was cooled to 0 ° C to precipitate I

In the C-terminal fragment 14-21. After centrifugation I

In 20, the supernatant was lyophilized and the soluble I

The components were purified by RP-HPLC to give I

In obtained the N-terminal fragment 1-13. '

In Reference Example 5 I

I 25 I

In Mass Spectrometry I

In Positive FAB mass spectra (Fig. 3), regi I

With a spectrometer VG 70/250 / SEQ equipped I

In with a cesium ion source. Samples were placed in 3- I

In nitrobenzyl alcohol / methanol matrix. IN

In the Value {M + H] +: 2166 M.U. confirmed it calculated- I

In the lower molecular mass. The spectrum of the daughter ions (Fig. I

In 3b), fragments Bu, B13, B14 and B15 show. These frag- I

DK 175198 el 15 ments are typical of the tryptic cleavage site and this overlap combines the results obtained for the separately analyzed N- and C-terminal fragments.

Thermospray ionization mass spectra were obtained using the HP 5988 (Hewlett Packard) thermospray system. Samples of the tryptic fragment 14-21 of gallidermin were injected. Positive ionization with additional electron impact was used and the ions were detected in the scanning region 350-950 mass units. In the significant region 350-550 mass units, detection of several fragments was obtained after background subtraction and confirmed via mass coelution.

The spectrum is shown in the scan region 350-550 dalton 15 in FIG. 2. The stability of Cys (Avi), which forms the amidated C-terminus, is remarkable because it forms the peak of the hb. A characteristic fourfold fragmentation each with twofold binding cleavage is characteristic of both C-terminal fragments gallids-20 min 14-21 and epidermin 14-21. Coelution of the masses confirms this particular pattern of fragmentation.

Reference Example 6 Peptide Sequencing

Gallidermin and its N-terminal fragment were sequenced by automated Edman degradation using a pulsed-liquid gas phase sequencer 477A with on-line PTH analyzer (Applied 30 Biosystems). Samples of RP-HPLC separations dissolved in the HPLC eluent were placed directly on the filter plate in the reaction chamber.

Sequencing and PTH analysis were performed

I DK 175198 B1 I

I 16 I

In with standard programs. IN

I This analysis showed the N-terminal sequence I

I Ile1-Ala2-x3-Lys4-Phes-Leui-x7-xe-Pro9-Gly10-xu-Ala12-I

In Lys13. IN

I The x shown at positions 3, 7, 8 and 11 indicates I

In those positions where no evidence was found

In amino acid derivatives. These positions correspond to one Lan- I

In 10 and one MeLan residue according to the amino acid composition of I

In the N-terminal fragment. IN

Because of the sulfide bridges and the special properties

In the bis-PTH-Lan maker, automatic decomposition cannot

You are assessed at these positions, but decomposition you go

15, however. The degradation yields for galli- I

is shown in FIG. 4. I

In the amino acid Leu was unambiguously detected in position I

I on 6. I

There is a characteristic enzymatic cleavage I

At 20 0 Lys13-Dhb14 in the central part of gallidermin. Un- I

In tryptic digestion, precipitation was observed

In the resulting C-terminal, uncharged and I

In hydrophobic fragment 14-21, while the N-terminal four- I

In fold loaded and hydrophilic fragments 1-13 remain in I

25 solution. IN

The cleavage rate of the Lys-Dhb bond is I

very slow compared to other bonds of Lys I

I with any protein amino acid. Like in

In the case of epidermin, tryptic rupture leads to I

For conversion of Dhb to 2-oxobutyryl residue, I

In which prevents structural information by Edman- I

In the degradation of the C-terminal fragment. IN

17 DK 175198 B1

Reference Example 7

Ultraviolet Analysis The UV spectrum of gallidermin confirms the vinyllic double bond at 267 nm exhibiting the very high extinction coefficient of 11000 M ^ cm * 1 (water, 0.1 mg / ml, d = 1 cm, 21 ° C) compared to the low value of tyros in absorption (1400 M'1cm'1). 2 2

Claims (8)

Pharmaceutical composition according to claim 2, characterized in that it is for topical use. IN Use of a compound according to claim 1 I for the preparation of a pharmaceutical composition, preferably for topical use, for the treatment of a bacterial infection, in particular skin infections such as eczema, I impetigo, cellulitis and acne. IN Process for the preparation of a compound according to claim 1, characterized in that a gallidermin-producing strain of Staphylococcus gallinarum is grown under conditions in which bile lidermine is expressed and secreted into the culture medium, after which the gallidermin is isolated from the culture medium and, if desired, converted to an acid addition salt thereof. Process according to claim 5, characterized in that said isolation process comprises treating the culture medium with an adsorbent, and then adsorption on a weak cation exchange resin, desalination and optionally an additional chromatographic purification step. Process for the preparation of a pharmaceutical composition according to claim 2, characterized in that a compound according to claim 1 is brought into close contact with a pharmaceutically acceptable carrier and / or excipient. Process according to claim 7, characterized in that a pharmaceutical composition for topical use is prepared. Cosmetic composition, characterized in that it contains a compound according to claim 1 in combination with a suitable carrier and / or excipient and preferably comprising collagen. 10. Antibiotic compound, characterized in that it is a compound which can be prepared from microorganisms of the strain Staphylococcus gallinarum DSM 4616 or mutant strains thereof, or is a physiologically acceptable salt of such a compound.