Polymyxin B: Controlled biosynthesis.

Polymyxin b: controlled biosynthesis.

The polymyxins form a group of closely related strongly basic cyclicpeptide antibiotics with a rather specific activity against gram-negative bacteria. The most well-known and commercially produced members are poly-myxin B and E (colistin). These two consists of polymyxin B1, B2, B3 and E1, E2, E " the single components of them differing only in the fatty acid moiety of the side chain attached ...

Chemical studies on polymyxin B.

Polymyxin B and heart muscle.

The effects of the polypeptide antibiotic, polymyxin B, on myocardial contractility were studied in t;e isolated rat heart muscle. Five different doses of polymyxin B were tested. There were no changes in contractility with does ranging from the clinical therapeutic value to three times greater. There was an initial increase and then depression with a dose six times greater than the therapeutic...

The Biosynthesis of Polymyxin B by Growing Cultures of Bacillus poZyrnyxa*

In the last two decades, numerous oligopeptides have been isolated from sporogenic bacteria and fungi. These peptides are almost invariably characterized by the presence of macrocyclic structures, linkages other than cr-peptide bonds, amino acids that do not occur in protein, n-amino acids, and nonamino acid moieties. The formation of some of these peptides by microorganisms has been studied in...

The Biosynthesis of Polymyxin B by Growing Cultures of Bacillus Polymyxa.

In the last two decades, numerous oligopeptides have been isolated from sporogenic bacteria and fungi. These peptides are almost invariably characterized by the presence of macrocyclic structures, linkages other than cr-peptide bonds, amino acids that do not occur in protein, n-amino acids, and nonamino acid moieties. The formation of some of these peptides by microorganisms has been studied in...