Arenosclerins A-C and haliclonacyclamine E, new tetracyclic alkaloids from a brazilian endemic haplosclerid sponge Arenosclera brasiliensis - Torres, Yohandra Reyes; Berlinck, Roberto Gomes de Souza; Magalhães, Alviclér; Schefer, Alexandre Bezerra; Ferreira, Antonio G.; Hajdu, Eduardo; Muricy, Guilherme (Journal of Natural Products, 2000)