title: Arenosclerins A-C and haliclonacyclamine E, new tetracyclic alkaloids from a Brazilian endemic Haplosclerid sponge Arenosclera brasiliensis.
abstract: Arenosclerins A (2), B (3), and C (4), as well as haliclonacyclamine E (1), are new tetracyclic alkylpiperidine alkaloids isolated from a new species of marine sponge belonging to the order Haplosclerida, Arenosclera brasiliensis, a species endemic to the southeastern Brazilian coast. The alkaloids were isolated as their hydrochloride salts and identified by analysis of spectroscopic data. Data obtained from (1)H-(1)H COSY, HMBC, and HSQC-TOCSY NMR experiments allowed complete assignment of the (1)H and (13)C resonances, and analysis of the NOESY and ROESY spectra showed that the only differences between 2, 3, and 4 were the relative stereochemistries of the bispiperidine ring system. Arenosclerins A-C are the first haliclonacyclamine/halicyclamine-related alkaloids with a hydroxy group in the bridging alkyl chain.
authors.affiliation: Instituto de Química de São Carlos, Universidade de São Paulo CP 780, CEP 13560-970, São Carlos, SP, Brasil.
authors.forename: Y R
authors.initials: YR
authors.lastname: Torres
authors.forename: R G
authors.initials: RG
authors.lastname: Berlinck
authors.forename: A
authors.initials: A
authors.lastname: Magalhães
authors.forename: A B
authors.initials: AB
authors.lastname: Schefer
authors.forename: A G
authors.initials: AG
authors.lastname: Ferreira
authors.forename: E
authors.initials: E
authors.lastname: Hajdu
authors.forename: G
authors.initials: G
authors.lastname: Muricy
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification*; D000818:Animals; D001938:Brazil; D002850:Chromatography, Gel; D002855:Chromatography, Thin Layer; D047028:Macrocyclic Compounds; D009682:Magnetic Resonance Spectroscopy; D010880:Piperidines / Q000737:chemistry / Q000302:isolation & purification*; D011161:Porifera / Q000737:chemistry*; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000470:Alkaloids; D047028:Macrocyclic Compounds; D010880:Piperidines; C414423:arenosclerin A; C414424:arenosclerin B; C414425:arenosclerin C; C414422:haliclonacyclamine E