Further chemical study of secondary metabolites from the soil actinomycete Streptomyces sp. WS-13394 resulted in the isolation of four new alkylated anthraquinone analogues (5-8). Their structures were elucidated on the basis of extensive spectroscopic analysis, including HR-ESI-MS, 1D and 2D NMR. The new compounds, together with analogues obtained before (1-4), were tested for their in vitro cytotoxicity against Huh-7 and SGC-7901.