Sterol Chemotaxonomy of Marine Pelagophyte Algae |
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Authors: | José‐Luis Giner Hui Zhao Gregory L. Boyer Michael F. Satchwell Robert A. Andersen |
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Affiliation: | 1. Department of Chemistry, State University of New York‐ESF, Syracuse, NY 13210, USA, (phone: +1‐315‐470‐6895;2. fax: +1‐315‐470‐6856);3. Bigelow Laboratory for Ocean Sciences, West Boothbay Harbor, ME 04575, USA |
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Abstract: | Several marine algae of the class Pelagophyceae produce the unusual marine sterol 24‐propylidenecholesterol, mainly as the (24E)‐isomer. The (24Z)‐isomer had previously been considered as a specific biomarker for Aureococcus anophagefferens, the ‘brown tide’ alga of the Northeast coast of the USA. To test this hypothesis and to generate chemotaxonomic information, the sterol compositions of 42 strains of pelagophyte algae including 17 strains of Aureococcus anophagefferens were determined by GC analysis. A more comprehensive sterol analysis by HPLC and 1H‐NMR was obtained for 17 selected pelagophyte strains. All strains analyzed contained 24‐propylidenecholesterol. In all strains belonging to the order Sarcinochrysidales, this sterol was found only as the (E)‐isomer, while all strains in the order Pelagomonadales contained the (Z)‐isomer, either alone or together with the (E)‐isomer. The occurrence of Δ22 and 24α‐sterols was limited to the Sarcinochrysidales. The first occurrence of Δ22‐24‐propylcholesterol in an alga, CCMP 1410, was reported. Traces of the rare sterol 26,26‐dimethyl‐24‐methylenecholesterol were detected in Aureococcus anophagefferens, and the (25R)‐configuration was proposed, based on biosynthetic considerations. Traces of a novel sterol, 24‐propylidenecholesta‐5,25‐dien‐3β‐ol, were detected in several species. |
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Keywords: | Aureococcus anophagefferens Marine sterols Chemotaxonomy Sterol Pelagophyte algae Cholesterol, 24‐propylidene‐ Biomarkers |
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