A comparison of benzyl and 2-naphthylmethyl ethers as permanent hydroxyl protecting groups in the synthesis of α-galactoglycosphingolipids KRN7000 and PBS-57

<p>Due to the interest in the biological properties of marine derived α-galactoglycosphingolipids (α-GalGSLs), a lot of work has focused on the development of their synthesis. Here we conducted the direct comparison of benzyl and 2-naphthylmethyl (Nap) ethers as permanent hydroxyl protecting groups for the synthesis of KRN7000, as well as the practical synthesis of a biologically active α-GalGSLs PBS-57. This work further revealed the advantages of Nap ether over benzyl ether for permanent hydroxyl protection in the synthesis of α-GalGSLs.</p

Damicoside from Axinella damicornis : the influence of a glycosylated galactose 4-OH group on the immunostimulatory activity of a-galactoglycosphingolipids

α-Galactoglycosphingolipids (α-GalGSLs) are unique immunostimulatory glycosphingolipids from marine sponges. Analysis of the glycosphingolipid composition of the marine sponge Axinella damicornis revealed the presence of a new α-GalGSL, damicoside (3a), which is the first α-GalGSL with a glycosylated galactose 4-OH group. Structure elucidation of damicoside was performed using spectroscopic and chemical methods. When tested in a spleen cell proliferation assay, 3a exhibited a stimulatory activity comparable to that of agelasphin (2), showing that a free galactose 4-OH group is not essential for the immunostimulatory activity of α-GalGSLs and providing a further step toward the complete understanding of their structure-activity relationship