Sinulariapeptide F, a new peptide from culture broth of marine-derived fungus Simplicillium sp. SCSIO 41222

Abstract

One new compound named sinulariapeptide F (1) together with one known butyrolactone (2) and seven known peptides (3-9) were isolated from the fungus Simplicillium sp. SCSIO 41222. Their structures and absolute configurations were established using HRESIMS, NMR spectroscopy (¹H, ¹³C, HSQC, HMBC) and marfey's method. All of these compounds were assessed their inhibitory activity of acetylcholinesterase (AChE) and pancreatic lipase (PL). Compounds 4 and 6 were selected to test for the inhibitory activity against programmed cell death-1 (PD-1)/ programmed cell death-ligand 1 (PD-L1). The results indicated that compound 4 displayed potent inhibition activity against PD-1/ PD-L1 with an IC₅₀ value of 0.656 μM. Furthermore, the docking analysis demonstrated the interactions between 4 and proteins, suggesting PD-L1 to be a probable target for compound 4.