Synthesis of sulfated oligosaccharide glycosides having high anti-HIV activity and the relationship between activity and chemical structure

Sulfated laminara-oligosaccharide glycosides having high anti-human immunodeficiency virus (HIV) activities were synthesized from laminara-tetraose, -pentaose and -hexaose. The oligosaccharide glycosides were synthesized by treating peracetylated β-oligosaccharides with various alcohols and Lewis acid catalysts. The effects of the number of glucose residues and the alkyl chain-length on anti-HIV activity were examined. The anti-HIV activity of sulfated dodecyl laminara-pentaosides and -hexaosides increased with increasing degree of sulfation (DS) and the pentaoside having an almost fully-sulfated saccharide portion had the highest activity, whereas for the hexaoside a somewhat lower DS manifested the highest activity. Sulfated laminara-oligosaccharide glycosides having fluoroalkyl-containing aglycons of high hydrophobicity showed potent inhibitory effects against HIV infection. In contrast, hydrophilic substituents containing oligo(ethyleneoxy) groups as aglycons in the sulfated oligosaccharides did not show high anti-HIV activity.