H. White, C. Alverson, M. Baker
Jun 1, 1949
Citations
0
Influential Citations
27
Citations
Journal
Annals of the New York Academy of Sciences
Abstract
Polymyxin is a generic term which has been ~ s e d l ~ to designate nonhomogeneous antibiotic material produced by Bacillus polymyxa. ‘(Aerosporin” is the trademarked name introduced by Ainsworth, Brown, and BrownleelO to designate a similar product from the same bacterial species. A comparison of the original publicationsl-10 on polymyxin and “Aerosporin” strongly suggested that they were either identical or very closely related. Consequently, it became a matter of considerable interest to make a comparative study of the two substances to evaluate, by means of side-byside tests, their points of similarity and difference. Such a study has been made possible through the mutual exchange of representative samples. The sample of “Aerosporin” (61 P 48) used in the present investigation was obtained froni Dr. George Brównlee of the Wellcome Physiological Research Laboratories. It had an ascribed potency of 7940 “Aerosporin” units per milligram and, thus, was considered to be about 79 per cent “pure”.ll A11 comparative data have been based on the use of a sample of polymyxin (B71-91-2) with a potency of 1540 Çtamford units per milligram, or a “purity” of approximately 77 per cent.’ Both samples are mixtures of basic polypeptides and, although chemical studies are incomplete, a definite difference in their composition has already been firmly established.12J3 Hydrolysates of either polymyxin or “Aerosporin” contain leucine, threonine, a , y-diaminobutyric acid, and an as yet unidentified Cg acid. In addition to these components, polymyxin, but not “Aerosporin,” contains the amino acid serine. In this investigation, polymyxin and “Aerosporin” (as represented by the samples described above) have been compared with reference to their in vitro activity under various test conditions, iherapeutic effectiveness in experimental infections, and acute toxicity for mice. Since, for a11 practical purposes, the samples were of equivalent purity, a11 comparisons have been made on a weight-for-weight basis.