ElaiophylinS1448

Azalomycin-B possesses an antibacterial activity against Gram-positive bacteria. The minimum inhibitory concentration (MIC) of Azalomycin-B against Staphylococcus aureus (SG 511, 285 and 503) is 1.52 μM. The MIC of Azalomycin-B against Streptococcus pyogenes is 0.76 μM and 1.52 μM for strains 306A, and 77A, respectively. The MIC of Azalomycin-B against S. faecium A is 3.05 μM. ^[1] In vitro, Azalomycin-B shows an antibiotic activity as a rumen fermentation efficiency enhancer and also inhibits lactic acid production in the rumen fluid with IC5O of 2.14 μM. ^[2] Azalomycin-B inhibits P-type ATPases such as the P-type, K⁺-dependent ATPase from Escherichia coli, without affecting F-type and V-type ATPases at all. ^[3] Azalomycin-B shows the potent cytotoxic effect on L929 mouse fibroblast cells, K562 human leukemia cells and HeLa cell cultures with IC50 of 0.29 μM, 0.19 μM and 0.29 μg/mL, respectively. ^[4] Moreover, Azalomycin-B also produces the cytotoxicity in MRC-5 cells with IC50 of 0.85 μM. ^[5]