Journal Article

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

Karsten, Ulf, Remias, Daniel, Becker, Kathrin, Hartmann, Anja, Ganzera, Markus

2015

Overview

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.

• Publisher: MDPI AG,MDPI
• Subject: Algae / Amino acids / Amino Acids - chemistry / Amino Acids - isolation & purification / Catenella / Chromatography, Liquid - methods / Correlation coefficient / Cyanobacteria - metabolism / Cyclohexanols - chemistry / Cyclohexanols - isolation & purification / Cyclohexanones - chemistry / Cyclohexanones - isolation & purification / Cyclohexylamines - chemistry / Cyclohexylamines - isolation & purification / Glycine - analogs & derivatives / Glycine - chemistry / Glycine - isolation & purification / HILIC / Hydrophobic and Hydrophilic Interactions / isolation / LC-MS / Limit of Detection / Liquid chromatography / Magnetic Resonance Spectroscopy / Marine / Mass spectrometry / Mass Spectrometry - methods / Metabolites / mycosporine-like amino acids / NMR / Nuclear magnetic resonance / quantification / Rhodophyta - metabolism / Secondary Metabolism / Secondary metabolites / UV-sunscreen / validation