In the framework of a project to assess the immunomodulating properties of α‐galactosyl glycosphingolipids, the total synthesis of 1‐O‐(2‐fluoro‐2‐deoxy‐α‐D‐galactopyranosyl)‐2‐docosanoylamino‐1,3,4‐octadecanetriol (1), a 2'‐fluoro analogue of the immunostimulating α‐galactoglycosphingolipids, was accomplished. The glycosidation reaction of the azido precursor of sphingosine was performed using the Mukaiyama glycosidation reaction. The stimulation of mouse splenocyte proliferation by the 2'‐fluoro analogue was highly reduced compared to that of the α‐galactoglycosphingolipids, thereby confirming that a free galactose 2‐OH group is essential for the immunostimulatory activity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

Discoside (1a), a glycolipid composed of 4,6-O-diacylated mannose attached to the 2-hydroxyl group of a myo-inositol unit, was isolated as a mixture of homologues from the marine sponge Discodermia dissoluta. The complete stereostructure of this new glycolipid was solved by interpretation of mass spectrometric and NMR data and CD analysis of degradation products.

The total synthesis of 1‐2‐docosanoylamino‐O‐(2‐O‐methyl‐α‐D‐galactopyranosyl)‐1,3,4‐octadecanetriol (2), a 2′‐methoxy analog of the immunostimulating α‐galactoglycosphingolipid 1, is reported. Stereoselective α‐glycosylation of the azido precursor of sphingosine was successfully performed for the first time using an improved Mukaiyama reaction. When assayed in a 72 h splenocyte proliferation test, compound 2 was significantly less stimulatory than the non‐methylated compound 1, suggesting that the galactose 2‐OH group is essential for the immunostimulatory activity of α‐Gal‐GSLs. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

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Lipids Lipids U 0750Immunomodulatory α-Galactoglycosphingolipids: Synthesis of a 2'-O-Methyl-−α-Gal-GSL and Evaluation of Its Immunostimulating Capacity. -(BARBIERI, L.; COSTANTINO*, V.; FATTTORUSSO, E.; MANGONI, A.; ARU, E.; PARAPINI, S.; TARAMELLI, D.; Eur.