title: Pestalotiopens A and B: stereochemically challenging flexible sesquiterpene-cyclopaldic acid hybrids from Pestalotiopsis sp.
abstract: From the endophytic fungus Pestalotiopsis sp. isolated from the leaves of the Chinese mangrove, Rhizophora mucronata, two novel hybrid sesquiterpene-cyclopaldic acid metabolites with an unusual carbon skeleton, named pestalotiopens A and B, were obtained, together with the already known phytotoxin altiloxin B. Pestalotiopen B even contains a third, triketide-derived module. The constitutions and the absolute configurations of the new metabolites and of altiloxin B were unambiguously determined by a combination of spectroscopic methods and quantum-chemical optical-rotatory dispersion (ORD) and circular dichroism (CD) calculations. A biosynthetic pathway to pestalotiopens A and B is proposed with altiloxin B as one of the suggested precursors. Pestalotiopen A shows moderate antimicrobial activity against Enterococcus faecalis.
authors.affiliation: Institute of Organic Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg (Germany), Fax: (+49)931-3184755.
authors.forename: Yasmin
authors.initials: Y
authors.lastname: Hemberger
authors.forename: Jing
authors.initials: J
authors.lastname: Xu
authors.forename: Victor
authors.initials: V
authors.lastname: Wray
authors.forename: Peter
authors.initials: P
authors.lastname: Proksch
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.forename: Gerhard
authors.initials: G
authors.lastname: Bringmann
mesh_terms: D001572:Benzofurans / Q000737:chemistry; D005658:Fungi / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry*; D043982:Rhizophoraceae / Q000737:chemistry*; D012717:Sesquiterpenes / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D001572:Benzofurans; D012717:Sesquiterpenes; C000590275:pestalotiopen A; C000590276:pestalotiopen B; C016326:cyclopaldic acid
keywords: altiloxin B; chirality; conformational analysis; quantum-chemical calculations; structure elucidation