title: Total synthesis and biological evaluation of amphidinolide V and analogues.
abstract: The awesome power of metathesis is illustrated by a concise synthesis of the extremely scarce marine natural product amphidinolide V, which hinges on a sequence of ring-closing alkyne metathesis followed by intermolecular enyne metathesis with ethylene (see scheme). As a complete set of conceivable stereoisomers was prepared, the constitution and absolute configuration of this macrolide could be established and first insights into structure-activity relationships governing its cytotoxicity were obtained.A sequence of ring-closing alkyne metathesis followed by an intermolecular enyne metathesis of the resulting cycloalkyne with ethene was used to forge the macrocyclic skeleton and to set the vicinal exo-methylene branches characteristic for the cytotoxic marine natural product amphidinolide V (1). Comparison of the synthetic material with an authentic sample of this extremely scarce metabolite isolated from a dinoflagellate of the Amphidinium sp. eliminated any doubts about its structure and allowed the absolute configuration of amphidinolide V to be determined as 8R,9S,10S,13R. Moreover, the flexibility inherent to the underlying synthesis blueprint also opened access to a comprehensive set of diastereomers of 1 as well as to synthetic analogues differing from the natural lead in the lipophilic chains appended to the macrocyclic core. This set of designed analogues gave first insights into structure-activity relationships, which revealed that the stereostructure of the macrolactone is a highly critical parameter, whereas the examined alterations of the side chain did not diminish the cytotoxicity of the compounds to any notable extent.
authors.affiliation: Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr, Germany.
authors.forename: Alois
authors.initials: A
authors.lastname: Fürstner
authors.forename: Susanne
authors.initials: S
authors.lastname: Flügge
authors.forename: Oleg
authors.initials: O
authors.lastname: Larionov
authors.forename: Yohei
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Takaaki
authors.initials: T
authors.lastname: Kubota
authors.forename: Jun'ichi
authors.initials: J
authors.lastname: Kobayashi
mesh_terms: D000475:Alkenes; D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D003500:Cyclization; D004141:Dinoflagellida / Q000737:chemistry; D004354:Drug Screening Assays, Antitumor; D018942:Macrolides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D008387:Marine Toxins / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D015394:Molecular Structure; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D000097442:Amphidinolides
chemical_list: D000475:Alkenes; D000970:Antineoplastic Agents; D018942:Macrolides; D008387:Marine Toxins; C522824:amphidinolide V; D000097442:Amphidinolides