Bioactive Secondary Metabolites from an Arctic Marine-Derived Strain, Streptomyces sp. MNP-1, Using the OSMAC Strategy

An Arctic marine-derived strain, MNP-1, was characterized by a combined methodological approach, incorporating a variety of analytical techniques including morphological features, biochemical characteristics, and 16S ribosomal RNA (rRNA) sequence analysis. The chemical investigation of <i>Streptomyces</i> sp. MNP-1 using the OSMAC (one strain many compounds) strategy yielded the isolation of twenty known compounds (<b>1-20</b>), which were unambiguously identified by various spectroscopic approaches including ¹H and ¹³C NMR and ESI-MS (previously reported data). Bioassay results indicated that compounds <b>2</b>, <b>3</b>, <b>5</b>, <b>9</b>, <b>14</b>, <b>15</b>, and <b>20</b> had antimicrobial activity against human pathogenic strains including <i>Staphylococcus aureus</i>, <i>Escherichia coli</i>, and <i>Candida albicans</i> with MIC values ranging from 4 to 32 μg/mL, and compounds <b>3</b> and <b>14</b> exhibited moderate inhibitory activity on A549, MCF-7, and HepG2 tumor lines showing IC₅₀ values within the range of 19.88 to 35.82 µM. These findings suggest that <i>Streptomyces</i> sp. MNP-1 is one of the prolific manufacturers of bioactive secondary metabolites with therapeutic potential.