title: Isolation and synthesis of (-)-(5S)-2-imino-1-methylpyrrolidine-5- carboxylic acid from Cliona tenuis: structure revision of pyrostatins.
abstract: [reaction: see text] (-)-(5S)-2-Imino-1-methylpyrrolidine-5-carboxylic acid (1), previously reported as the N-acetyl-beta-d-glucosaminidase inhibitor pyrostatin B, has been isolated from the organic extracts of the burrowing sponge Cliona tenuis. The structure of 1, including its absolute stereochemistry, was characterized from its spectral data and chemical transformations and confirmed by total synthesis. The synthesis of 1 reveals that the structure of pyrostatin B has been incorrectly assigned. Comparison of NMR spectral data strongly suggests that pyrostatins A and B are identical to 5-hydroxyectoine and ectoine, respectively.
authors.affiliation: Departamento de Química, Universidad Nacional de Colombia, AA 14490 Bogota, Colombia.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Castellanos
authors.forename: Carmenza
authors.initials: C
authors.lastname: Duque
authors.forename: Sven
authors.initials: S
authors.lastname: Zea
authors.forename: Alfonso
authors.initials: A
authors.lastname: Espada
authors.forename: Jaime
authors.initials: J
authors.lastname: Rodríguez
authors.forename: Carlos
authors.initials: C
authors.lastname: Jiménez
mesh_terms: D000599:Amino Acids, Diamino / Q000737:chemistry*; D000818:Animals; D007097:Imines / Q000138:chemical synthesis* / Q000737:chemistry* / Q000302:isolation & purification; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D011161:Porifera / Q000737:chemistry*; D011759:Pyrrolidines / Q000138:chemical synthesis* / Q000737:chemistry* / Q000302:isolation & purification; D013237:Stereoisomerism
chemical_list: D000599:Amino Acids, Diamino; D007097:Imines; D011759:Pyrrolidines; C121557:hydroxyectoine; C094715:pyrostatin B; C045628:ectoine; C094714:pyrostatin A