The structure of cerexin B (studies on antibiotics from the genus Bacillus. XVII)

The structure of cerexin B was examined. The constitutent fatty acids were elucidated by gas chromatography and mass spectrometry to be beta-hydroxy isodecanoic acid, beta-hydroxy decanoic acid, beta-hydroxy isoundecanoic acid and beta-hydroxy anteisoundecanoic acid. The configurations of constituent amino acids were determined as asparagine (2D, 1L), valine (D), phenylalanine (D), allo-threonine (D), tryptophan (D), and allo-isoleucine (D) from their optical activities. Treatment with conc. hydrochloric acid cleaved at the gamma-hydroxylysine residue to give two peptide fragments, one of which (the N-terminal side) was then deacylated with Polymyxin Acylase. Their amino acid sequences were examined by EDMAN degradation. From the results and analogy to cerexin A, the structure of cerexin B was deduced.