Hymenin, a novel alpha-adrenoreceptor blocking agent from the Okinawan marine sponge Hymeniacidon sp

A novel bromine-containing alkaloid, hymenin, has been isolated from the Okinawan marine sponge Hymeniacidon sp. as a potent alpha-adrenoceptor blocking agent and its structure determined to be 1 on the basis of the spectral data.