Antibacterial compounds and process for production thereof

The antibacterial compound S551-II (Reductiomycin) is produced by culturing a microorganism belonging to the genus Streptomyces. S551-II-A is prepared by sublimation of the compound S551-II.

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.

EXAMPLE 1 
Composition of fermentation medium (as same as seed medium): 
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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.degree. 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.degree. 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.