Lenzimycins A and B, Metabolites With Antibacterial Properties From sp. Associated With the Dung Beetle .

Symbiotic microorganisms associated with insects can produce a wide array of metabolic products, which provide an opportunity for the discovery of useful natural products. Selective isolation of bacterial strains associated with the dung beetle, , identified two strains, of which the antibiotic-producing sp. PTH23 inhibited the growth of sp. CCARM 9248, which is most closely related to the well-known entomopathogen, . A comprehensive chemical investigation based on antibiotic activity discovered two new antibiotics, named lenzimycins A and B (-), which inhibited growth of sp. CCARM 9248. The H and C NMR, MS, MS/MS, and IR analyses elucidated the structures of and , which comprised a novel combination of fatty acid (12-methyltetradecanoic acid), glycerol, sulfate, and -methyl ethanolamine. Furthermore, the acid hydrolysis of revealed the absolute configuration of 12-methyltetradecanoic acid as 12 by comparing its optical rotation value with authentic ()- and ()-12-methyltetradecanoic acid. In addition to inhibition of sp. CCARM 9248, lenzimycins A and B were found to inhibit the growth of some human pathogenic bacteria, including and certain strains of Furthermore, the present study elucidated that lenzimycins A and B activated a reporter system designed to detect the bacterial cell envelope stress, thereby indicating an activity against the integrity of the bacterial cell wall.