Novel intact glycolipids in sediments from an Antarctic lake (Ace Lake)

• Main Authors: Sinninghe Damsté, J.S., Dongen, B.E. van, Reiss-Schaeffer, C., Schouten, S., Volkman, J.K., Geenevasen, J.A.J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2001
• Subjects: Aardwetenschappen; Ace Lake; Antarctic; Antarc*
• Online Access: https://dspace.library.uu.nl/handle/1874/4377

Two novel glycolipids, docosanyl 3-O-methyl--rhamnopyranoside and docosanyl 3-O-methylxylopyranoside, were identified as the most abundant GC-amenable components of extracts of sediments of Ace Lake, an Antarctic meromictic lake. Docosanyl 3-O-methyl--rhamnopyranoside was identified by isolation and high-field two-dimensional NMR techniques. Docosanyl 3-O-methylxylopyranoside was tentatively identified by characterisation of its sugar moiety by methanolysis and demethylation. Both glycolipids also have a minor homologue, containing a C24 instead of a C22 n-alkyl chain. Stable carbon isotope measurements indicate that the sugar moieties of these glycolipids are ca. 8 9 enriched relative to the alkyl chains. Concentrations increased markedly with depth reaching 2 mg/g sediment at 25 cm depth. Structurally related glycolipids occur in specialised cells of nitrogen-fixing cyanobacteria, so a cyanobacterial origin is suggested for these sedimentary glycolipids.