Bioactive Streptoglutarimides A–J from the Marine-Derived Streptomyces sp. ZZ741

Abstract

The new streptoglutarimides A−J (1−10) and the known streptovitacin A (11) were isolated from a marinederived 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 IC 50 values 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.

Identification of trans-AT polyketide clusters in two marine bacteria reveals cryptic similarities between distinct symbiosis factors

“…Compound 5 has a molecular formula C 26 H 37 NO 9 deduced from its ESIMS m/z 508. 3 13 C NMR data. Detailed 2D NMR spectroscopic analyses indicated that 5 possessed the same core structure as 4 linked at C13 with a dicarboxylic unsaturated eleven-carbon chain through esterification.…”

“…The active fraction containing compounds 1 and 2 was eluted with EtOAc-MeOH 9:1 (25 mg) and was further purified by semi-preparative reversedphase HPLC using a Symmetry C18 column (19x150 mm, 7 µm) and a linear gradient of H 2 O/CH 3 CN from 5% to 65% of CH 3 CN over 30 min at a flow rate of 13 mL/min, to afford fourteen fractions (1-14). The active fraction 3 between 9-10 min (5 mg) afforded a mixture of compounds 1 and 2 identified by 1 H, 13 C NMR and HPLCMS spectra. The active silica gel fraction eluted with EtOAc-MeOH 3:1 (28 mg) also showed by NMR spectra characteristic signals of sesbanimide compounds.…”

“…Recently, two new methylstreptimidone analogs have been isolated showing moderate antitumor activity (12). Apart from antitumor activity against human glioma, streptoglutarimides isolated from a marine actinomycete have also shown antibacterial and antifungal properties (13).…”

“…Known glutarimide polyketides have been isolated from actinomycetes (12)(13)(14)(15)(16) with the exception of recently identified gladiofungin from Burkholderia gladioli (17). Nevertheless, the production of the sesbanimide analogs has been attributed to Gram-negative bacteria, i.e., marine Agrobacterium strains, PH-103 and PH-A034C, isolated from the tunicates Ecteinascidia turbinata collected in Florida and Polycitonidae sp.…”

Antibiotics Development and the Potentials of Marine-Derived Compounds to Stem the Tide of Multidrug-Resistant Pathogenic Bacteria, Fungi, and Protozoa

“…ZZ741 (China) that produced new streptoglutarimides A−J (1−10) as well as a known streptovitacin A (11). Some of these compounds displayed antiproliferative properties, and antimicrobial activity against test pathogens which includes MRSA (MIC, 8−12 µg/mL) [40].…”