Batumin 1, 2E,10Z,12E-20-(3-aminocarboxy)-2-methyl-1-oxobutylamino-7-methylene-17-oxo -19-oxy-3,5,15-trimethyleicosa-2,10,12-trienoic acid, is an antibiotic produced by the strains of Pseudomonas batumici ( Fig. 1). 1 It shows very good activity particularly against Gram-negative bacteria, eg, Staphylococcus aureus, 2 and 3 which pose a serious health problem due to their resistance against antibiotics in current use. Batumin's basic structural elucidation was ...