title: Novel approach to determine ghrelin analogs by liquid chromatography with mass spectrometry using a monolithic column.
abstract: In our project, ghrelin analogs possessing enhanced stability and potential to significantly increase food intake were used. Three newly synthesized ghrelin analogs with fatty acid residues consisting of 8, 10, and 14 carbon atoms were studied. The main goal of this work was to develop a suitable analytical method for the determination of the stability of the novel ghrelin analogs in plasma. An appropriate liquid chromatography-mass spectrometry method was developed and optimized. The results obtained were compared with the data measured by using a commercial enzyme-linked immunosorbent assay kit, and a good correlation was found. A preparation strategy for plasma samples was optimized and consisted of simple dilution of the plasma samples followed by direct injection onto a very short monolithic column in combination with mass spectrometric detection. The developed analytical method was utilized for the determination of the stability of the prepared lipopeptides in plasma and for the quantification of the lipopeptides in a preliminary pharmacokinetic study. The feasibility of the developed separation method was clearly demonstrated. Accuracy and precision were within 80-120% and ±20% limits, respectively. Calibration curves were constructed in the range of 1-250 μg/mL.
authors.affiliation: Department of Analytical Chemistry, University of Chemistry and Technology Prague, Prague, Czech Republic.|Institute of Organic Chemistry and Biochemistry AS CR, Prague, Czech Republic.
authors.forename: Jana
authors.initials: J
authors.lastname: Zemenova
authors.affiliation: Department of Analytical Chemistry, University of Chemistry and Technology Prague, Prague, Czech Republic.
authors.forename: David
authors.initials: D
authors.lastname: Sykora
authors.affiliation: Department of Analytical Chemistry, University of Chemistry and Technology Prague, Prague, Czech Republic.
authors.forename: Hana
authors.initials: H
authors.lastname: Adamkova
authors.affiliation: Institute of Organic Chemistry and Biochemistry AS CR, Prague, Czech Republic.
authors.forename: Lenka
authors.initials: L
authors.lastname: Maletinska
authors.affiliation: Institute of Organic Chemistry and Biochemistry AS CR, Prague, Czech Republic.
authors.forename: Tomas
authors.initials: T
authors.lastname: Elbert
authors.affiliation: Institute of Organic Chemistry and Biochemistry AS CR, Prague, Czech Republic.
authors.forename: Ales
authors.initials: A
authors.lastname: Marek
authors.affiliation: Institute of Organic Chemistry and Biochemistry AS CR, Prague, Czech Republic.
authors.forename: Miroslava
authors.initials: M
authors.lastname: Blechova
mesh_terms: D002138:Calibration; D002853:Chromatography, Liquid; D054439:Ghrelin / Q000031:analogs & derivatives*; D055666:Lipopeptides / Q000097:blood; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry
chemical_list: D054439:Ghrelin; D055666:Lipopeptides
keywords: enzyme-linked immunosorbent assay; ghrelin; lipopeptides; liquid chromatography mass spectrometry; monolithic columns