Production of Unusual Dispiro Metabolites inPestalotiopsis virgatulaEndophyte Cultures: HPLC-SPE-NMR, Electronic Circular Dichroism, and Time-Dependent Density-Functional Computation Study

Journal of Natural Products
2011.0

Abstract

The endophytic fungus Pestalotiopsis virgatula, derived from the plant Terminalia chebula and previously found to produce a large excess of a single metabolite when grown in the minimal M1D medium, was induced to produce a variety of unusual metabolites by growing in potato dextrose broth medium. Analysis of the fermentation medium extract was performed using an HPLC-PDA-MS-SPE-NMR hyphenated system, which led to the identification of a total of eight metabolites (1-8), six of which are new. Most of the metabolites are structurally related and are derivatives of benzo[c]oxepin, rare among natural products. This includes dispiro derivatives 7 and 8 (pestalospiranes A and B), having a novel 1,9,11,18-tetraoxadispiro[6.2.6.2]octadecane skeleton. Relative and absolute configurations of the latter were determined by a combination of NOESY spectroscopy and electronic circular dichroism spectroscopy supported by time-dependent density-functional theory calculations (B3LYP/TZVP level). This work demonstrates that a largely complete structure elucidation of numerous metabolites present in a raw fermentation medium extract can be performed by the HPLC-SPE-NMR technique using only a small amount of the extract, even with unstable metabolites that are difficult to isolate by traditional methods.

Knowledge Graph

Similar Paper

Production of Unusual Dispiro Metabolites in<i>Pestalotiopsis virgatula</i>Endophyte Cultures: HPLC-SPE-NMR, Electronic Circular Dichroism, and Time-Dependent Density-Functional Computation Study
Journal of Natural Products 2011.0
Polyketide derivatives of endophytic fungus Pestalotiopsis sp. isolated from the Chinese mangrove plant Rhizophora mucronata
Tetrahedron Letters 2011.0
Pestalotheols A−D, Bioactive Metabolites from the Plant Endophytic Fungus <i>Pestalotiopsis theae</i>
Journal of Natural Products 2008.0
Disseminins and Spiciferone Analogues: Polyketide-Derived Metabolites from a Fungicolous Isolate of <i>Pestalotiopsis disseminata</i>
Journal of Natural Products 2016.0
Chlorotheolides A and B, Spiroketals Generated via Diels–Alder Reactions in the Endophytic Fungus <i>Pestalotiopsis theae</i>
Journal of Natural Products 2016.0
Ambuic Acid and Torreyanic Acid Derivatives from the Endolichenic Fungus <i>Pestalotiopsis</i> sp.
Journal of Natural Products 2009.0
Characterization of Polyketide Metabolites from Foliar Endophytes of <i>Picea glauca</i>
Journal of Natural Products 2008.0
Pestaloficiols A–E, bioactive cyclopropane derivatives from the plant endophytic fungus Pestalotiopsis fici
Bioorganic &amp; Medicinal Chemistry 2008.0
Four new tetramic acid and one new furanone derivatives from the plant endophytic fungus Neopestalotiopsis sp.
Fitoterapia 2015.0
Two new alkaloid metabolites produced by endophytic fungus Stagonosporopsis oculihominis isolated from Dendrobium huoshanense
Phytochemistry Letters 2017.0