Synthesis and Antiproliferative Activity of Marine Bromotyrosine Purpurealidin I and Its Derivatives.

The first total synthesis of the marine bromotyrosine purpurealidin I () using trifluoroacetoxy protection group and its dimethylated analog () is reported along with 16 simplified bromotyrosine derivatives lacking the tyramine moiety. Their cytotoxicity was evaluated against the human malignant melanoma cell line (A-375) and normal skin fibroblast cells (Hs27) together with 33 purpurealidin-inspired simplified amides, and the structure⁻activity relationships were investigated. The synthesized simplified analogs without the tyramine part retained the cytotoxic activity.