AN ALDEHYDE-CONTAINING GALACTOLIPID FROM THE RED ALGA GRACILARIOPSIS-LEMANEIFORMIS

An unprecedented aldehyde-containing digalactosyldiacylglycerol (DGDAG) has been isolated from the red alga Gracilariopsis lemaneiformis and structurally defined. Its structure was determined as 1-O-[5-hydroxy-12-oxododeca-6 (E),8(E),10(E)-trienoyl]-2-O-palmitoyl-3-O-[-beta-D-galactopyranosyl-6, 1-alpha-D-galactopyranosyl]-glycerol by nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry and degradation to simple fragments. The identification of this aldehyde-containing DGDAG from G. lemaneiformis, in addition to our previous findings of unusual galactolipids, further indicates that this alga has unique lipoxygenase capacities.