The new streptoglutarimides A−J (1−10) and the known streptovitacin A (11) were isolated from a marine-derived actinomycete, Streptomyces 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 (8) and streptovitacin A (11) showed potent antiproliferative activity against human glioma U87MG and U251 cells with IC50values of 1.5−3.8 μM for 8 and 0.05−0.22 μM for 11. All isolated compounds exhibited antimicrobial activity with MIC values of 9−11 μg/mL against methicillin-resistant Staphylococcus aureus, 8−12 μg/mL against Escherichia coli, and 8−20 μg/mL against Candida albicans.