| Autor: |
Todorović B; Department of Botany and Plant Physiology, Faculty of Agriculture and Life Sciences, University of Maribor, Pivola 10, SI-2311 Hoce, Slovenia., Grujić VJ; Department of Biology, Faculty of Natural Sciences and Mathematics, University of Maribor, Koroška 160, SI-2000 Maribor, Slovenia.; Department of Elementary Education, Faculty of Education, University of Maribor, Koroška 160, SI-2000 Maribor, Slovenia., Krajnc AU; Department of Botany and Plant Physiology, Faculty of Agriculture and Life Sciences, University of Maribor, Pivola 10, SI-2311 Hoce, Slovenia., Kranvogl R; National Laboratory of Health, Environment and Food, Prvomajska 1, SI-2000 Maribor, Slovenia., Ambrožič-Dolinšek J; Department of Botany and Plant Physiology, Faculty of Agriculture and Life Sciences, University of Maribor, Pivola 10, SI-2311 Hoce, Slovenia.; Department of Biology, Faculty of Natural Sciences and Mathematics, University of Maribor, Koroška 160, SI-2000 Maribor, Slovenia.; Department of Elementary Education, Faculty of Education, University of Maribor, Koroška 160, SI-2000 Maribor, Slovenia. |
| Abstrakt: |
Haematococcus pluvialis , a unicellular green microalga that produces a secondary metabolite under stress conditions, bears one of the most potent antioxidants, namely xanthophyll astaxanthin. The aim of our study was to determine the content of astaxanthin and its esterified forms using three different solvents-methyl tert -butyl ether (MTBE), hexane isopropanol (HEX -IPA) and acetone (ACE)-and to identify them by using high performance liquid chromatography coupled with diode array detection and the quadrupole time-of-flight mass spectrometry (HPLC-DAD and LC-QTOF-MS) technique. We identified eleven astaxanthin monoesters, which accounted for 78.8% of the total astaxanthin pool, six astaxanthin diesters (20.5% of total), while free astaxanthin represented the smallest fraction (0.7%). Astaxanthin monoesters (C16:2, C16:1, C16:0), which were the major bioactive compounds in the H. pluvialis samples studied, ranged from 10.2 to 11.8 mg g -1 DW. Astaxanthin diesters (C18:4/C18:3, C18:1/C18:3) were detected in the range between 2.3 and 2.6 mg g -1 DW. All three solvents were found to be effective for extraction, but MTBE and hexane-isopropanol extracted the greatest amount of free bioactive astaxanthin. Furthermore, MTBE extracted more low-chain astaxanthin monoesters (C16), and hexane-isopropanol extracted more long-chain monoesters (C18 and above) and more diesters. We can conclude that MTBE is the solvent of choice for the extraction of monoesters and hexane-isopropanol for diesters. |
