Bioactive Bromophycolides R−U from the Fijian Red Alga Callophycus serratus

Four new bromophycolides, R−U (1−4), were isolated from the Fijian red alga Callophycus serratus and were identified by 1D and 2D NMR and mass spectroscopic analyses. These compounds expand the known structural variety of diterpene-benzoate macrolides and exhibited modest cytotoxicity toward selected human cancer cell lines. Bromophycolide S (2) also showed submicromolar activity against the human malaria parasite Plasmodium falciparum.