title: Analysis of Mycosporine-Like Amino Acids in Selected Algae and Cyanobacteria by Hydrophilic Interaction Liquid Chromatography and a Novel MAA from the Red Alga Catenella repens.
abstract: Mycosporine-like amino acids (MAAs), a group of small secondary metabolites found in algae, cyanobacteria, lichens and fungi, have become ecologically and pharmacologically relevant because of their pronounced UV-absorbing and photo-protective potential. Their analytical characterization is generally achieved by reversed phase HPLC and the compounds are often quantified based on molar extinction coefficients. As an alternative approach, in our study a fully validated hydrophilic interaction liquid chromatography (HILIC) method is presented. It enables the precise quantification of several analytes with adequate retention times in a single run, and can be coupled directly to MS. Excellent linear correlation coefficients (R² > 0.9991) were obtained, with limit of detection (LOD) values ranging from 0.16 to 0.43 µg/mL. Furthermore, the assay was found to be accurate (recovery rates from 89.8% to 104.1%) and precise (intra-day precision: 5.6%, inter-day precision ≤6.6%). Several algae were assayed for their content of known MAAs like porphyra-334, shinorine, and palythine. Liquid chromatography-mass spectrometry (LC-MS) data indicated a novel compound in some of them, which could be isolated from the marine species Catenella repens and structurally elucidated by nuclear magnetic resonance spectroscopy (NMR) as (E)-3-hydroxy-2-((5-hydroxy-5-(hydroxymethyl)-2-methoxy-3-((2-sulfoethyl)amino)cyclohex-2-en-1-ylidene)amino) propanoic acid, a novel MAA called catenelline.
authors.affiliation: Institute of Pharmacy, Pharmacognosy, University of Innsbruck, Innrain 80-82, Innsbruck 6020, Austria. Anja.Hartmann@uibk.ac.at.
authors.forename: Anja
authors.initials: A
authors.lastname: Hartmann
authors.affiliation: Division of Biological Chemistry, Biocenter, Medical University of Innsbruck, Innrain 80-82, Innsbruck 6020, Austria. Kathrin.Becker@i-med.ac.at.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Becker
authors.affiliation: Institute of Biological Sciences, Applied Ecology & Phycology, University of Rostock, Albert-Einstein-Str. 3, Rostock 18059, Germany. Ulf.Karsten@uni-rostock.de.
authors.forename: Ulf
authors.initials: U
authors.lastname: Karsten
authors.affiliation: University of Applied Sciences Upper Austria, Stelzhammerstr. 23, Wels 4600, Austria. Daniel.Remias@fh-wels.at.
authors.forename: Daniel
authors.initials: D
authors.lastname: Remias
authors.affiliation: Institute of Pharmacy, Pharmacognosy, University of Innsbruck, Innrain 80-82, Innsbruck 6020, Austria. Markus.Ganzera@uibk.ac.at.
authors.forename: Markus
authors.initials: M
authors.lastname: Ganzera
mesh_terms: D000596:Amino Acids / Q000737:chemistry* / Q000302:isolation & purification; D002853:Chromatography, Liquid / Q000379:methods*; D000458:Cyanobacteria / Q000378:metabolism*; D003511:Cyclohexanols / Q000737:chemistry / Q000302:isolation & purification; D003512:Cyclohexanones / Q000737:chemistry / Q000302:isolation & purification; D003514:Cyclohexylamines / Q000737:chemistry / Q000302:isolation & purification; D005998:Glycine / Q000031:analogs & derivatives / Q000737:chemistry / Q000302:isolation & purification; D057927:Hydrophobic and Hydrophilic Interactions; D057230:Limit of Detection; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry / Q000379:methods; D000461:Rhodophyta / Q000378:metabolism*; D064210:Secondary Metabolism
chemical_list: D000596:Amino Acids; D003511:Cyclohexanols; D003512:Cyclohexanones; D003514:Cyclohexylamines; C523105:palythine; C421025:porphyra-334; C494891:shinorine; D005998:Glycine
keywords: HILIC; LC-MS; UV-sunscreen; isolation; mycosporine-like amino acids; quantification; validation