Pyloricidins, novel anti-Helicobacter pylori antibiotics produced by Bacillus sp. II. Isolation and structure elucidation

Novel anti-Helicobacter pylori antibiotics, pyloricidins A, A(1), A(2), B, C and D were isolated from Bacillus sp. HC-70 and Bacillus sp. HC-72 by col umn chromatographies using adsorption and ion exchange resins. Their struct ures have been elucidated based on spectroscopic and degradation studies an d shown to be peptide-like compounds. These compounds contained two unusual amino acids, viz.. 5-amino-2,3,4,6-tetrahydroxyhexanoic acid and 3-amino-3 -phenylpropionic acid (beta -phenylalanine). The structure-activity relatio nship studies suggested that 3-(5-amino-2,3,4,6-tetrahydroxyhexanoyl)amino- 3-phenylpropionic acid moiety was essential for anti-H. pylori activity.