RESUMEN
In addition to several known sterols, a new C(29) marine sterol with a normal ergosterol nucleus but a modified side chain, named 26-nor-25-isopropyl-ergosta-5,7,22E-trien-3beta-ol, was isolated from the Jamaican sponge Agelas sceptrum. The structures were assigned by spectroscopic methods including high-resolution 2D NMR techniques.
Asunto(s)
Ergosterol/biosíntesis , Poríferos/química , Animales , Ergosterol/análogos & derivados , Ergosterol/química , Jamaica , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Poríferos/clasificaciónRESUMEN
In addition to the sesquiterpene-phenol aureols (1), 6'-chloroaureol (2), and aureol acetate (3), eight indole alkaloids including the new N-3'-ethylaplysinopsin (9) have been isolated from the Jamaican sponge Smenospongia aurea. Makaluvamine O (10), a new member of the pyrroloiminoquinone class, was also isolated. The structures were characterized by spectroscopic methods, and two new derivatives of aureol were prepared to optimize the biological activity. Aureol N,N-dimethyl thiocarbamate (1a) and 6-bromoaplysinopsin (7) exhibit significant antimalarial and antimycobacterial activity in vitro. Compound 6 showed activity against the Plasmodium enzyme plasmepsin II. The 6-bromo-2'-de-N-methylaplysinopsin (6), 6-bromoaplysinopsin (7), and N-3'-ethylaplysinopsin (9) displaced high-affinity [(3)H]antagonist ligands from cloned human serotonin 5-HT(2) receptor subtypes, whereas the other compounds tested did not. Remarkably, the 6-bromo-2'-de-N-methylaplysinopsin (6) showed a > 40-fold selectivity for the 5-HT(2C) subtype over the 5-HT(2A) subtype.