SYNTHESIS OF SULFATED ALKYL LAMINARA-OLIGOSACCHARIDES HAVING POTENT ANTI-HIV ACTIVITY AND THE RELATIONSHIP BETWEEN STRUCTURE AND BIOLOGICAL-ACTIVITIES

The synthesis of potently anti-HIV-active sulfated alkyl laminara-oligosaccharides composed of glucosidic residues of 5-9 was investigated. The anti-HIV activity and the anticoagulant activity of these sulfated alkyl laminara-oligosaccharides were assessed. The synthesis and separation of respective laminara-oligosaccharides were accomplished in a route starting from acetolysis and hydrolysis of curdlan followed by HPLC. Alkyl oligosaccharides were synthesized using stannic tetrachloride as a Lewis acid catalyst, and then sulfation was carried out with the sulfur trioxide-pyridine complex after deacetylation. Sulfated dodecyl laminarapentaoside through laminaranonaoside showed almost the same anti-HIV activity. Although no cytotoxicity was detected on a series of dodecyl compounds, low-level cytotoxicity appeared with a series of octadecyl compounds. On the other hand, the anticoagulant activity increased as the number of sugar units increased from 5 to 9.