title: Isolation and characterization of diastereomers of discorhabdins H and K and assignment of absolute configuration to discorhabdins D, N, Q, S, T, and U.
abstract: Investigations of four different sponge populations of Latrunculia species collected in New Zealand waters has led to the characterization of a new diastereomer of discorhabdin H, named discorhabdin H2, confirmation of the structure of discorhabdin K ((+)-7), and presentation of a new diastereomer, discorhabdin K2 ((-)-8). In each case the structures were established by extensive NMR and MS studies and the absolute configurations interrogated by electronic circular dichroism (ECD). Absolute configurations were assigned to the known metabolites discorhabdins H, D, 2-hydroxy-D, N, and Q by comparison of ECD spectra with those recorded for discorhabdin alkaloids of defined absolute configuration, while the configurations of discorhabdins S, T, and U were assigned by semisynthesis from (+)-(6S,8S)-discorhabdin B.
authors.affiliation: Department of Chemistry, The University of Auckland, Private Bag 92019, Auckland, New Zealand.
authors.forename: Tanja
authors.initials: T
authors.lastname: Grkovic
authors.forename: A Norrie
authors.initials: AN
authors.lastname: Pearce
authors.forename: Murray H G
authors.initials: MH
authors.lastname: Munro
authors.forename: John W
authors.initials: JW
authors.lastname: Blunt
authors.forename: Michael T
authors.initials: MT
authors.lastname: Davies-Coleman
authors.forename: Brent R
authors.initials: BR
authors.lastname: Copp
mesh_terms: D000470:Alkaloids / Q000737:chemistry; D000818:Animals; D015394:Molecular Structure; D009520:New Zealand; D011161:Porifera / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry* / Q000302:isolation & purification*; D015363:Quinolones; D011809:Quinones / Q000737:chemistry* / Q000302:isolation & purification*; D013141:Spiro Compounds / Q000737:chemistry* / Q000302:isolation & purification*; D013237:Stereoisomerism; D013841:Thiazepines
chemical_list: D000470:Alkaloids; D011758:Pyrroles; D015363:Quinolones; D011809:Quinones; D013141:Spiro Compounds; D013841:Thiazepines; C573536:discorhabdin B; C000606013:discorhabdin H; C000606015:discorhabdin K; C482818:discorhabdin S