“…Following bioassay-guided fractionation of the most active sponge Monanchora viridis , we isolated crambescidin 800 (C800), a guanidine alkaloid, as an active compound against TNBC cells. Guanidine alkaloids from sponges of genus Monanchora are reported to have diverse chemical structures and biological activities [ 21 , 22 , 23 , 24 ], which includes inducing cytotoxic activities [ 25 , 26 ] and apoptosis against leukemia cells [ 25 , 27 ], overcoming drug resistance by induction of autophagy and lysosomal membrane permeabilisation in urogenital cancer cells [ 28 ], and inhibiting HIV-1 fusion [ 29 ], transient receptors potential channels [ 30 ], and EGF-induced neoplastic transformation in cancer cells [ 31 ]. It was also reported that the alteration of the compound’s structure affected its cytotoxic activities, inducing apoptosis, cell cycle progression, and the induction of signaling pathways in cancer cells [ 31 ].…”