<jats:p> A new chlorinated metabolite designated chlokamycin (1), was isolated along with ikarugamycin (2) from the culture broth of the marine-derived Streptomyces sp. MA2–12. The structure of 1 was elucidated based on spectroscopic analyses (1D and 2D NMR data and ROESY correlations). Chlokamycin moderately inhibited the growth of Jurkat cells and HCT116 cells with IC<jats:sub>50</jats:sub> values of 24.7 and 33.5 μM, respectively.