Abstract
The structure of permetin A(I), an antibiotic substance produced by Bacillus circalans AJ 3902, has been elucidated as a cyclic acyl peptide by means of the mass and nuclear magnetic resonance spectroscopic techniques. C2H5CH-CH-CH2-CO-L-DCb-L-Ile→L-Dob→D-Phe CH3O L-Ser←L-Leu←D-Val←L-Dab←L-Leu The structure was found to be the same as polypeptin A(II) except that L-Thr in II is replaced by L-Ser in I. Details of the structural determination are given for the permetin A itself as well as for the hydrolyzed permetin A. C2H5CH-CH-CH2-CO→L-Dab→L-Ile→L-Dab→D-Phe CH3 O L-Thr←L-Leu←D-VoI←L-Dob-L-Leu II
