Bisamides and rhamnosides from mangrove actinomycete Streptomyces sp. SZ-A15

Four new bisamides 1–4, and two new rhamnosides (5, 6), along with four known compounds 7–10, were isolated from a scale culture of the mangrove-derived actinomycete Streptomyces sp. SZ-A15. All structures were determined through analysis of the UV, IR, HRESIMS, 1D and 2D NMR spectra as well as by comparison with literature data. BRD4 inhibition of all isolated compounds was evaluated. As for the ability to inhibit protein BRD4, compound 9 exhibited moderate activity with the value of 78.4 ± 2.2% at 10 μM.