Effect of chemical modification at C1 of the glucosamine backbone of lipid A-subunit analog GLA-27 on manifestation of immunopharmacological activity.

The effect of chemical modification at the C1 position of GLA-27, 4-O-phosphono-D-glucosamine carrying N-3-tetradecanoyloxytetradecanoyl [C14-O-(C14)] and 3-O-tetradecanoyl (C14) groups, was investigated. Replacement by SH or S-acetyl groups of the OH group resulted in the enhancement of mitogenicity but gave rise to a reduction, in macrophage-stimulating ability such as induction of tumor necrosis factor and enhancement of phagocytic and cellular acid phosphatase activities. Bisphosphorylation at C1 and C4 resulted in a slight decrease in mitogenicity or almost complete loss of the macrophage-stimulating ability.