Antibacterial compounds and process for production thereof
This is a division of application Ser. No. 878,776 filed Feb. 17, 1978. 
    
    
     SUMMARY OF THE INVENTION 
     The present invention relates to new antibacterial compounds S551-II (Reductiomycin) and S551-II-A. The compound S551-II is produced by culturing a microorganism belonging to the genus Streptomyces in a nutrient medium. The compound S551-II-A is produced by sublimating the compound S551-II. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     FIG. 1 shows the infrared absorption spectrum of the compound S551-II. 
     FIG. 2 shows the infrared absorption spectrum of the compound S551-II-A. 
     FIG. 3 shows the nuclear magnetic resonance spectrum of the compound S551-II. 
     DETAILED EXPLANATION OF THE INVENTION 
     The present invention relates to new antibacterial compounds represented by the following general formula: ##STR1## (the compound having the following formula ##STR2## is referred to as Compound S551-II hereinafter) or ##STR3## (the compound having the following formula ##STR4## is referred to as S551-II-A hereinafter.). 
     The compound S551-II is also designated as Reductiomycin. 
     The antibacterial compound S551-II is produced by culturing a microorganism belonging to the genus Streptomyces and being capable of producing the antibacterial compound in a nutrient medium. The antibacterial compound is accumulated in the culture medium and is isolated therefrom. 
     The antibacterial compound S551-II-A is produced by sublimation of the compound S551-II. 
     The present compound S551-II has the following physicochemical properties. 
     Appearance: A yellow fine crystal. 
     Melting point: 215° C. (decompose). 
     [α] D   23 ° : +281° (c=0.30, acetone). 
     Molecular weight: 293 (by the mass spectrometry). 
     Elementary analysis: C: 57.36%, H: 5.25%, N: 4.73%. Molecular formula: C 14  H 15  O 6  N. 
     Ultraviolet absorption spectrum (the maximum value, ε value): 273 nm (28655) (in methanol); 288 nm (21600) (in 0.1 N HCl-methanol). 
     Color reactions: 
     Ehrlich&#39;s reaction (in HCl): positive 
     Ferric chloride reaction: positive 
     Nitroprusside reaction (in alkaline): positive 
     2,4-Dinitrophenylhydrazine reaction: positive 
     Pine-shaving reaction: negative 
     Ninhydrin reaction: negative 
     Schiff&#39;s reaction: negative 
     Sakaguchi&#39;s reaction: negative 
     Infrared absorption spectrum by the paste method is illustrated in FIG. 1. 
     PMR spectrum measured in CDCl 3  by using TMS as an internal standard is illustrated in FIG. 3. 
     Based on the foregoing data, the compound S551-II is considered to have the structural formula shown earlier. 
     The compound S551-II-A has the following physicochemical properties. 
     Appearance: A yellowish crystal 
     Melting point: 215° C. (sublimate) 
     [α] D   23 ° : 0° (c=0.30, dimethylsulfoxide) 
     Molecular weight: 233 (by the mass spectrometry). Elementary analysis: C: 60.98%, H: 4.59%, N: 6.06%. Molecular formula: C 12  H 11  O 4  N. 
     Ultraviolet absorption spectrum (the maximum value, ε value): 260 nm (52900) (in methanol and 0.1 N-NaOH.) 
     Color reactions: 
     Ehrlich&#39;s reaction (in HCl): positive 
     Ferric chloride reaction: positive 
     2,4-dinitrophenylhydrazine reaction: positive 
     Ninhydrin reaction: negative 
     Schiff&#39;s reaction: negative 
     Sakaguchi&#39;s reaction: negative 
     Nitroprusside reaction: negative 
     Solubilities: The compound is soluble in acetone, dimethylsulfoxide and alkaline solution, slightly soluble in methanol and insoluble in bezene, chloroform ethylether and hexane. 
     Infrared absorption spectrum of S551-II-A by the paste method is illustrated in FIG. 2. 
     Based on the foreging data, the compound S551-II-A is considered to have the structural formula shown earlier. 
     Now, the process for producing S551-II is described below. 
     The new antibacterial compound S551-II is produced by culturing a microorganism belonging to the genus Streptomyces and being capable of producing the compound. A suitable microorganism belongs to Streptomyces griseorubiginosus. Its typical strain is Streptomyces griseorubiginosus KY 11448 (FERM-P 3836) (NRRL 11,268). 
     The strain has the following properties. 
     I. MORPHOLOGY 
     The spore forming mycelium shows flexous simple branching. A chain of ten or more spores is formed. 
     The surface of the spore is smooth and the diameter of its minor axis and major axis are 1.0μ and 2.5μ, respectively. The sporophore is formed on the aerial mycelium. 
     II. CULTURE CHARACTERISTICS 
     
         ______________________________________                                    
           Color of the                                                   
           substrate mycelium                                             
                                 The                                      
                 Aerial    The   reverse                                  
                                        Soluble                           
Medium  Growth   Mycelium  surface                                        
                                 side   pigment                           
______________________________________                                    
Sucrose-                                                                  
        Poor     Poor      White White                                    
nitrate Flat     White(a)  (a)   (a)    None                              
agar                                                                      
Glucose-                                                                  
        Moderate Moderate  Cream Light                                    
asparagine                                                                
        Raised   Light     (11/2a)                                        
                                 Yellow None                              
agar             Ivory           (11/2ea)                                 
                 (2ca)                                                    
Glycerin-                                                                 
        Moderate Moderate  Cream Light                                    
asparagine                                                                
        Flat     Light     (11/2a)                                        
                                 Yellow None                              
agar             Ivory           (11/2ea)                                 
                 (2ca)                                                    
Starch  Good     Good      Cream Light  Butter                            
agar    Raised   Cream     (11/2a)                                        
                                 Yellow Yellow                            
                 (11/2a)         (11/2 ea)                                
                                        (11/2ea)                          
Tyrosine                                                                  
        Good     Good      Dull  Mustard                                  
                                        Antique                           
agar    Raised   Cream     Gold  Brown  Gold                              
                 (11/2a)   (2ng) (2ni)  (11/2ne)                          
Nutrient                                                                  
        Good               Bright                                         
                                 Bright Amber                             
agar    Raised   None      Gold  Gold   (3pc)                             
                           (2nc) (2nc)                                    
Yeast   Good     Good      Golden                                         
                                 Golden Mustard                           
extract-                                                                  
        Raised   Putty     Brown Brown  Gold                              
malt             (11/2ec)  (3pg) (3pg)  (2ne)                             
extract                                                                   
agar                                                                      
Oatmeal Good               Dull  Dull   Clove                             
agar    Raised   None      Gold  Gold   Brown                             
                           (2ng) (2ng)  (3ni)                             
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     The color indications are given according to the classifications in the Color Harmony Manual (Container Corporation of America). 
     III. PHYSIOLOGICAL PROPERTIES 
     Growth temperature: 25° to 38° C. 
     Liquefaction of gelatin: negative 
     Hydrolysis of starch: positive 
     Coagulation and peptonization of skim milk: negative 
     Liquefaction of skim milk: positive 
     Formation of melanoid pigments: positive 
     IV. UTILIZATION OF CARBON SOURCES______________________________________Carbon source        Utilization______________________________________D-Arabinose          -D-Xylose             -D-Glucose            2+D-Fructose           2+Sucrose              -Inositol             -L-Rhamnose           -Raffinose            +D-Mannitol           2+______________________________________ 
     On the basis of the above observations and the description of E. Kuster, International Journal of Systematic Bacteriology 22 (3), 139 (1972), the strain is identified as Streptomyces griseorubiginosus. 
     As the fermentation medium employed in the present process, any synthetic or natural medium can be employed, so long as it contains a proper carbon source, a nitrogen source, inorganic materials and other necessary nutrients for the growth of the microorganism. 
     As the carbon source, various carbohydrates such as glucose, fructose, sucrose, galactose, xylose, sorbitol, mannitol, glycerol, starch, starch hydrolyzate liquor, molasses, blackstrap molasses, etc., various hydrocarbon such as ethane, propane, butane, n-paraffine, kerosene, etc., various organic acid such as acetic acid, fumaric acid, succinic acid, lactic acid, pyruvic acid and alcohols such as methanol, ethanol, etc. may be used. 
     As the nitrogen source, aqueous ammonia, various inorganic and organic ammonium salts such as ammonium sulfate, ammonium chloride, ammonium phosphate, ammonium acetate, etc.; urea, acid amides, amines, amino acids, defatted cotton seed, meat extract, yeast extract, corn steep liquor, casein hydrolyzate, fish meal or its digested product, defatted soybean or its digested product, soybean protein hydrolyzate; various microbial cells or its digested product, etc. may be used. 
     As inorganic materials, dipotassium monohydrogen phosphate, monopotassium dihydrogen phosphate, magnesium sulfate, sodium chloride, ferrous sulfate, manganese sulfate, calcium carbonate, magnesium phosphate, etc. may be used. 
     If other nutrients are necessary for the growth of the microorganisms used in the present invention, they must, of course, be present in the medium. They are sometimes supplied to the medium together with natural materials exemplified as a nitrogen source. 
     Culturing is carried out under aerobic conditions such as with shaking or aeration-agitation. Suitable culturing temperature is usually 23° to 38° C. It is desirable to keep the pH of the medium at 3 to 8, preferably around neutrality throughout culturing. 
     Culturing is usually carried out for 1 to 7 days to accumulate the compound S551-II in the culture liquor. 
     After completion of the culturing, microbial cells and precipitates are removed from the culture liquor by filtration or centrifugation and the compound S551-II may be recovered and isolated from the resultant solution by combination of ion exchange treatment, column chromatography using silica gel, etc. 
     The compound S551-II-A is prepared as follows. The compound S551-II is heated at a temperature of 215° or more and is sublimated accompanying with deacetic acid reaction to form compound S551-II-A. The product crystallized on the glass plate was collected and washed with methanol to obtain a pure S551-II-A as crystals. 
     The antibacterial activity of the compound S551-II against various microorganisms by disc method (pH: no adjustment) is shown in the following Table 1. 
     
                       Table 1                                                     
______________________________________                                    
Microorganism tested    MIC (mcg/ml)                                      
______________________________________                                    
Aspergillus niger IAM 2026                                                
                        250                                               
Aspergillus niger ATCC 6275                                               
                        1,000                                             
Aspergillus oryzae NRRL 692                                               
                        62.5                                              
Penicillium chrysogenum IAM 7142                                          
                        125                                               
Penicillium chrysogenum O 174                                             
                        62.5                                              
Mucor Spinescens IAM 6071                                                 
                        500                                               
Dusarium moniliforme IAM 5062                                             
                        125                                               
Myrothecium verrucaria IAM 5063                                           
                        125                                               
Trycophyton mentagrophytes IAM 5064                                       
                        4                                                 
Mrycoderma T-1 ATCC 9645                                                  
                        16                                                
Chactomium globosum ATCC 6025                                             
                        500                                               
Microsporum gypseum IFO 5948                                              
                        125                                               
Alternaria solani IFO 5924                                                
                        8                                                 
Cladosporium herbarum Link Fr IAM 5059                                    
                        31.2                                              
Bacillus subtilis PCI 219                                                 
                        62.5                                              
Bacillus subtilis IAM 1026                                                
                        31.2                                              
Bacillus subtilis NA 64 62.5                                              
Sarcina lutea IAM 1099  125                                               
Staphylococcus aureus FAD 209P                                            
                        62.5                                              
Diplococcus pneumoniae  1000                                              
Escherichia coli IAM 1268                                                 
                        1000                                              
Escherichia coli ATCC 3655                                                
                        500                                               
Serratia marcescens IAM 1022                                              
                        &gt;1000                                             
Proteus vulgaris HX19 IAM 1025                                            
                        &gt;1000                                             
Pseudomonas aeruginosa IAM 1156                                           
                        &gt;1000                                             
Pseudomonas fluorescens ATCC 27                                           
                        &gt;1000                                             
Salmonella enteritidis  &gt;1000                                             
Shigella sonnei E23     &gt;100                                              
Klebsiella pneumoniae 348                                                 
                        &gt;1000                                             
Candida albicans IAM 4888                                                 
                        &gt;1000                                             
Saccharomyces cerevisiae IAM 4485                                         
                        1000                                              
Saccharomyces rouxii M-9                                                  
                        1000                                              
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     The antibacterial activity of the compound S551-II-A against various microorganism by agar dilution method (pH 7.0) is shown in Table 2. 
     
                       Table 2                                                     
______________________________________                                    
Microorganism tested   MIC (mcg/ml)                                       
______________________________________                                    
Bacillus subtilis ATCC 10707                                              
                       200                                                
Staphylococcus aureus ATCC 6538P                                          
                       200                                                
Klebsiella pneumoniae ATCC 10031                                          
                       200                                                
Proteus vulgaris ATCC 6897                                                
                       25                                                 
Escherichia coli ATCC 3655                                                
                       500                                                
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     As it is obvious from above description, compounds of the present invention are useful to clean and disinfect laboratory glassware and surgical instruments, and may also be used in combination with various soaps for sanitation purposes and in cleaning and sanitizing hospital rooms and areas used for the preparation of food. 
     Practice of certain specific embodiments of the invention is illustrated by the following representative examples. 
    
    
     EXAMPLE 1 
     Composition of fermentation medium (as same as seed medium): 
     
         ______________________________________                                    
Soluble starch       2%                                                   
Gluten meal          2%                                                   
Defatted cotton seed 2%                                                   
Dry yeast            2%                                                   
CaCOhd 3             0.3%                                                 
MgSO.sub.4 . 7H.sub.2 O                                                   
                     0.07%                                                
Silicon K966         0.1% (V/V)                                           
(antifoaming agent)                                                       
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     Streptomyces griseorubiginosus KY 11448 (FERM-P No. 3836) (NRRL 11,268) is used as a seed strain. 
     200 ml of seed culture obtained by culturing the above seed strain in 300 ml of seed medium in a Sakaguchi-flask for 50 hrs in advance is transfered into 30 l-Jar containing 15 l of said fermentation medium. Culturing is carried out at 30° C. for 72 hrs with aeration of 14 l/min. and stirring at 300 r.p.m. 
     After culturing, culture broth is filtrated to remove microbial cells and the filtrate is extracted with about 15 l of ethylacetate. The resulting extract is concentrated to dryness under reduced pressure. The above separated microbial cells is extracted with acetone and the resulting extract is concentrated to dryness under reduced pressure. Then, the obtained residue is ectracted with ethylacetate and concentrated to dryness under reduced pressure. The resulting two residues are collected and is subjected to chromatography using silica gel (200 ml by volume) and then washed with 500 ml of benzene. Then, elution is carried out with each of 500 ml of benzene-methanol (1% by volume), benzene-methanol (2% by volume) and benzene-methanol (3% by volume). The eluates by benzene-methanol are collected and concentrated to dryness and then resulting residue is washed with about 30 ml of ethylether-chloroform (10:1 by volume). Then, recrystallization is carried out twice from about 8 ml of chloroform and about 5 ml of acetone, whereby 30 mg of compound S551-II is obtained as yellow fine crystal. 
     EXAMPLE 2 
     Synthesis of compound S551-II-A 
     Compound S551-II obtained in Example 1 is put on heater and is covered with Petri dish. Then, the compound is heated at 215° C. whereby compound S551-II is sublimated and the volatile component is adhered to wall of Petri dish to form crystals. The resulting crystals are collected and are washed with methanol, whereby pure compound S551-II-A is obtained.