| PATENT NUMBER | This data is not available for free |
| PATENT GRANT DATE | June 11, 1985 |
| PATENT TITLE |
Method of producing antibacterial agents and bioconverting microorganism therefor |
| PATENT ABSTRACT | Improved bioconverting strain of Streptomyces thermotolerans useful in preparing tylosin esters and new antibacterial macrocin or lactenocin ester derivatives of the formula: ##STR1## wherein R is formyl or hydroxymethyl; R.sup.1 is hydrogen, acetyl or propionyl; R.sup.2 is hydrogen or ##STR2## and R.sup.3 is hydrogen, acetyl, propionyl, n-butyryl or isovaleryl; provided that one of R.sup.1 or R.sup.3 must be other than hydrogen. |
| PATENT INVENTORS | This data is not available for free |
| PATENT ASSIGNEE | This data is not available for free |
| PATENT FILE DATE | March 3, 1983 |
| PATENT REFERENCES CITED |
Sebek et al., Genetics of Industrial Microorganisms, Pub. by American Society for Microbiology, pp. 117-122 (1979). M. Tsuchiya et al., "Studies on the Effects of 3-Acetyl-4"-Isovaleryltylosin Against Multiple-Drug Resistant Strains of Staphylococcus Aureus", J. Antibiotics 34(3), 305-306 (1981). M. Tsuchiya et al., "Studies of Tylosin Derivatives Effective Against Macrolide-Resistant Strains: Synthesis and Structure-Activity Relationships", J. Antibiotics 35(6), 661-671 (1982). Derwent Abstract Nos. 66634C/38, 27592A/15 of Japanese Unexamined Patent Nos. J5 5043-013, J5 3021-182, 3-26-80, 2-27-78 (Sanraku Ocean). Okamoto et al., "The Activity of 4"-Acylated Tylosin Derivatives Against Macrolide-Resistant Gram-Positive Bacteria: J. Antibiotics 32, 542-544 (1979). Okamoto et al., "Biological Properties of New Acyl Derivatives of Tylosin", J. Antibiotics 33, 1309-1315 (1980). |
| PATENT CLAIMS |
We claim: 1. A biologically purified culture of the microorganism Streptomyces thermotolerans NRRL 15270 or a mutant, variant or recombinant thereof which retains its improved ability to acylate macrocin, lactenocin and tylosin. 2. The culture of claim 1 wherein the microorganism is Streptomyces thermotolerans NRRL 15270. 3. A method of producing a compound of the formula ##STR17## wherein R.sup.1 is hydrogen, acetyl or propionyl; R.sup.2 is hydrogen, n-butyryl or isovaleryl; provided that one of R.sup.1 or R.sup.2 must be other than hydrogen, which comprises contacting tolysin with an acyl donor in the presence of an acylating enazyme system from that produced by Streptomyces thermotolerans NRRL 15270 in an aqueous medium until a substantial amount of the compound is produced. 4. The method of claim 3 wherein the enzyme system is present in the culture medium in which it is produced. -------------------------------------------------------------------------------- |
| PATENT DESCRIPTION |
SUMMARY OF THE INVENTION This invention provides a new strain of Streptomyces thermotolerans which has improved characteristics useful in the preparation of certain tylosin esters and in the preparation of macrocin and lactenocin derivatives having formula 1: ##STR3## wherein R is formyl or hydroxymethyl; R.sup.1 is hydrogen, acetyl or propionyl; R.sup.2 is hydrogen or ##STR4## and R.sup.3 is hydrogen, acetyl, propionyl, n-butyryl or isovaleryl; provided that one of R.sup.1 or R.sup.3 must be other than hydrogen. The compounds prepared using the microorganism of this invention are useful antibacterial agents. The formula 1 compounds are also useful in the treatment of Mycoplasma infections. DETAILED DESCRIPTION OF THE INVENTION We have discovered an improved Streptomyces thermotolerans strain which is useful in certain bioconversion reactions. More particularly, the Streptomyces thermotolerans strain of this invention has an improved ability to acylate macrocin and lactenocin to give the derivatives of formula 1. Furthermore, the S. thermotolerans strain of this invention has an improved ability to acylate tylosin to produce the tylosin derivatives described by R. Okamoto et al. in U.S. Pat. No. 4,092,473. Thus, this invention provides an improved process for preparing compounds of the formula ##STR5## wherein R.sup.1 is hydrogen, acetyl or propionyl; R.sup.2 is hydrogen, n-butyryl or isovaleryl; provided that one of R.sup.1 and R.sup.2 must be other than hydrogen. The S. thermotolerans strain of this invention is superior in several ways to the S. thermotolerans ATCC 11416 strain from which it was developed. The most important trait of the strain of this invention is its improved ability to acylate macrocin, lactenocin and tylosin to give useful compounds. The improved bioconverting strain of this invention was discovered among a group of 522 mutant strains of Streptomyces thermotolerans ATCC 11416. From this group of mutants, 192 were tested for their ability to acylate a macrolide antibiotic. Based on this study, 22 cultures were selected as superior in their ability to acylate the antibiotic. Of these, seven were chosen on the basis of favorable traits and tested further. The strain of the present invention was discovered among this group. When compared with both the parent culture and with the other selected mutants, the S. thermotolerans strain of this invention was superior to all in its ability to acylate the macrolide antibiotic at the 3- and 4"-positions. The new strain acylates the antibiotic more rapidly, giving better yields of the product derivative. In addition, the new strain provides consistent acylation, whereas the parent strain is erratic in its ability to acylate. The Streptomyces thermotolerans strain of this invention has been deposited and made part of the stock culture collection of the Northern Regional Research Center, Agricultural Research, North Central Region, 1815 North University Street, Peoria, Ill., 61604, from which it is available to the public under the accession number NRRL 15270. As is true with other organisms, the characeristics of Streptomyces thermotolerans NRRL 15270 are subject to variation. For example, recombinants, mutants or artificial variants of the NRRL 15270 strain may be obtained by treatment with various known physical and chemical mutagens, such as ultraviolet light, X-rays, gamma rays, and N-methyl-N'-nitro-N-nitrosoguanidine. All natural and artificial variants, mutants and recombinants of Streptomyces thermotolerans NRRL 15270 which retain its improved ability to acylate macrocin, lactenocin and tylosin may be used in this invention. The formula 1 compounds were discovered by Jan R. Turner, Veronica M. Krupinski, David S. Fukuda and Richard H. Baltz and are described in their copending application entitled Macrocin Derivatives and Process for Their Preparation, Ser. No. 471,628, filed herewith this even date. The formula 1 compounds can be prepared by contacting macrocin or lactenocin with an acyl donor in the presence of the acylating enzyme system from the S. thermotolerans strain of this invention. The enzyme system can be in the form of cells or enzyme preparations. The compounds of formula 1 wherein R is formyl are prepared initially in the bioconversion reaction. The compounds of formula 1 wherein R is hydroxymethyl, which are called the "C-20-dihydro" compounds, are prepared by reduction, either chemical or biochemical, of the formula 1 compounds wherein R is formyl. The compounds of formula 1 wherein R.sup.2 is ##STR6## are prepared when macrocin is used as the substrate in the bioconversion. The compounds of formula 1 wherein R.sup.2 is hydrogen can be prepared by using lactenocin in the bioconverting reaction |
| PATENT EXAMPLES | available on request |
| PATENT PHOTOCOPY | available on request |
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