Comosusols A-D and Comosone A: Cytotoxic Compounds from the Brown Alga Sporochnus comosus

Bioassay-guided fractionation Of extracts of., the brown alga Sporochnus comosus led to the isolation of five new compounds, comosusols A-D (3-6) and comosone A (7). The structures of all isolated,compounds were elucidated using standard one and two-dimensional NMR techniques, as well as comparison with literature values. The cytotoxic activity of all compounds was investigated against a panel of human tumor and mammalian. cell lines. These assays found eight of the nine compounds had GI(50) values in the 8-63 mu M range: