Two unprecedented dibromotyrosine-derived alkaloids from the Brazilian endemic marine sponge Aplysina caissara - Saeki, Beatriz Mari; Granato, Ana Claudia; Berlinck, Roberto Gomes de Souza; Magalhães, Alviclér; Schefer, Alexandre Bezerra; Ferreira, Antonio G.; Pinheiro, Ulisses S.; Hajdu, Eduardo (Journal of Natural Products, 2002)