title: Two unprecedented dibromotyrosine-derived alkaloids from the Brazilian endemic marine sponge Aplysina caissara.
abstract: Two new bromotyrosine-derived alkaloids, caissarine A (1) and caissarine B (2), along with three known biogenetically related alkaloids, aeroplysinin-1, fistularin-3, and the artifact of isolation 2-(3,5-dibromo-4-dimethoxy-1-hydroxy-2,5-cyclohexadien-1-yl)ethanamide, have been isolated from Aplysina caissara, an endemic species of marine sponge from the Southeastern Brazilian coast. The alkaloids have been identified by analysis of spectroscopic data. While caissarine A has a 2-hydroxyagmatine moiety in its structure, caissarin B is the first naturally occurring compound encompassing the unprecedented 1,7-diamino-3-hydroxyheptane moiety.
authors.affiliation: Instituto de Química de São Carlos, Universidade de São Paulo CP 780, CEP 13560-970, São Carlos, SP, Brazil.
authors.forename: Beatriz M
authors.initials: BM
authors.lastname: Saeki
authors.forename: Ana Claudia
authors.initials: AC
authors.lastname: Granato
authors.forename: Roberto G S
authors.initials: RG
authors.lastname: Berlinck
authors.forename: Alviclér
authors.initials: A
authors.lastname: Magalhães
authors.forename: Alexandre B
authors.initials: AB
authors.lastname: Schefer
authors.forename: Antonio G
authors.initials: AG
authors.lastname: Ferreira
authors.forename: Ulisses S
authors.initials: US
authors.lastname: Pinheiro
authors.forename: Eduardo
authors.initials: E
authors.lastname: Hajdu
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification*; D000818:Animals; D001938:Brazil; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D011161:Porifera / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014443:Tyrosine / Q000031:analogs & derivatives / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D000470:Alkaloids; C461800:caissarine A; C461801:caissarine B; D014443:Tyrosine