Carteritins A and B, cyclic heptapeptides from the marine sponge Stylissa carteri

Two new cyclic heptapeptides, carteritins A and B (1 and 2), were isolated from the marine sponge Stylissa carteri along with three known cyclic heptapeptides, phakellistatin 13 (3) and hymenamides C and D (4 and 5). Their structures were elucidated based on data obtained using 2D NMR, HRESIMS, and ESIMS/MS, in addition to Marfey's analysis. Carteritin A (1) showed cytotoxicities against HeLa, HCT116, and RAW264 cells with IC50 values of 0.70-1.5 mu M. (C) 2016 Elsevier Ltd. All rights reserved.