| Summary: | Four new streptoglycerides E–H (<b>1</b>–<b>4</b>), with a rare 6/5/5/-membered ring system, were isolated from a marine-derived actinomycete <i>Streptomyces specialis</i>. The structures of <b>1</b>–<b>4</b> were elucidated by detailed analysis of HRESIMS, 1D and 2D NMR data and ECD spectra as well as comparison of their spectroscopic data with those reported in literature. Compounds <b>1</b>–<b>4</b> showed significant anti-inflammatory activity by inhibiting lipopolysaccharide (LPS)-induced nitric oxide (NO) production in Raw 264.7 cells with IC<sub>50</sub> values ranging from 3.5 to 10.9 µM. Especially, <b>2</b> suppressed mRNA expression levels of iNOS and IL-6 without cytotoxicity.
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