Bioactive Streptoglutarimides A–J from the Marine-Derived <i>Streptomyces</i> sp. ZZ741

Abstract

The new streptoglutarimides A-J (<b>1</b>-<b>10</b>) and the known streptovitacin A (<b>11</b>) were isolated from a marine-derived actinomycete, <i>Streptomyces</i> sp. ZZ741. Structures of the isolated compounds were elucidated based on their HRESIMS data, extensive NMR spectroscopic analyses, ECD calculations, Mosher's method, and a single-crystal X-ray diffraction experiment. Streptoglutarimide H (<b>8</b>) and streptovitacin A (<b>11</b>) showed potent antiproliferative activity against human glioma U87MG and U251 cells with IC₅₀ values of 1.5-3.8 μM for <b>8</b> and 0.05-0.22 μM for <b>11</b>. All isolated compounds exhibited antimicrobial activity with MIC values of 9-11 μg/mL against methicillin-resistant <i>Staphylococcus aureus</i>, 8-12 μg/mL against <i>Escherichia coli</i>, and 8-20 μg/mL against <i>Candida albicans</i>.