Marine Streptomyces Sp. PGC 39: A Treasure Trove of New Antimicrobial Agents, Macrolidycin, and Pyrachlomycin

Macrolidycin (1) and pyrachlomycin (2) were isolated from the culture broth of the marine bacterium Streptomyces sp. GSCWU 39. The isolates were characterized due to 1D and 2D-NMR spectral analyses and high resolution mass spectrometry, and were evaluated for their anti -bacterial and anti -fungal activities. At a concentration of 30 mu g/mL, the compounds 1 and 2 inhibited the growth of a gram positive bacterium Streptomyces viridochromogenes and the fungus Mucor miehei. Further in order to deep the understanding for antibacterial and antifungal activities the isolates were docked against methyltransferase AviRb and ergosterol. Compounds 1 and 2 had strong binding energies of -7.32 and -6.32 kcal/mol, respectively, for the methyltransferase AviRb. Additionally, our findings for antifungal activities are further corroborated by the docking results of ergosterol with compounds 1 and 2.