| Title: | Chiral separation of a diketopiperazine pheromone from marine diatoms using supercritical fluid chromatography |
| Author(s): | Frenkel J; Wess C; Vyverman W; Pohnert G; |
| Address: | "Institute for Inorganic and Analytical Chemistry-Friedrich Schiller University Jena, Lessingstrasse 8, 07743 Jena, Germany. Electronic address: johannes.frenkel@uni-jena.de. Waters GmbH, Helfmann-Park 10, 65760 Eschborn, Germany. Electronic address: Carsten_Wess@waters.com. Laboratory of Protistology and Aquatic Ecology, Department of Biology, University Gent, Krijgslaan 281 S8 , 9000 Gent, Belgium. Electronic address: Wim.Vyverman@ugent.be. Institute for Inorganic and Analytical Chemistry-Friedrich Schiller University Jena, Lessingstrasse 8, 07743 Jena, Germany. Electronic address: georg.pohnert@uni-jena.de" |
| Journal Title: | J Chromatogr B Analyt Technol Biomed Life Sci |
| DOI: | 10.1016/j.jchromb.2013.12.040 |
| ISSN/ISBN: | 1873-376X (Electronic) 1570-0232 (Linking) |
| Abstract: | "The proline derived diketopiperazine has been identified in plants, insects and fungi with unknown function and was recently also reported as the first pheromone from a diatom. Nevertheless the stereochemistry and enantiomeric excess of this natural product remained inaccessible using direct analytical methods. Here we introduce a chiral separation of this metabolite using supercritical fluid chromatography/mass spectrometry. Several chromatographic methods for chiral analysis of the diketopiperazine from the diatom Seminavis robusta and synthetic enantiomers have been evaluated but neither gas chromatography nor high performance liquid chromatography on different chiral cyclodextrin phases were successful in separating the enantiomers. In contrast, supercritical fluid chromatography achieved baseline separation within four minutes of run time using amylose tris(3,5-dimethylphenylcarbamate) as stationary phase and 2-propanol/CO2 as mobile phase. This very rapid chromatographic method in combination with ESI mass spectrometry allowed the direct analysis of the cyclic dipeptide out of the complex sea water matrix after SPE enrichment. The method could be used to determine the enantiomeric excess of freshly released pheromone and to follow the rapid degradation observed in diatom cultures. Initially only trace amounts of c(d-Pro-d-Pro) were found besides the dominant c(l-Pro-l-Pro) in the medium. However the enantiomeric excess decreased upon pheromone degradation within few hours indicating that a preferential conversion and thus inactivation of the l-proline derived natural product takes place" |
| Keywords: | "Chromatography, Supercritical Fluid/*methods Cyclodextrins Diatoms/*chemistry Diketopiperazines/*analysis/chemistry/*isolation & purification Gas Chromatography-Mass Spectrometry Pheromones/*analysis/chemistry/*isolation & purification Stereoisomerism Chi;" |
| Notes: | "MedlineFrenkel, Johannes Wess, Carsten Vyverman, Wim Pohnert, Georg eng Research Support, Non-U.S. Gov't Netherlands 2014/02/11 J Chromatogr B Analyt Technol Biomed Life Sci. 2014 Mar 1; 951-952:58-61. doi: 10.1016/j.jchromb.2013.12.040. Epub 2014 Jan 13" |
