Sucrose octasulfate (SOS), a component of the gastrointestinal protectant sucralfate, is an alkaline aluminum?sucrose complex that inhibits peptic hydrolysis and raises gastric pH, protecting esophageal epithelium against acid injury. It can bind to exosite II of thrombin (KD = ~1.4 μM) and inhibit its catalytic activity (IC50 = 4.5 μM) and, as such, has been used as a surrogate for heparin. Furthermore, SOS has been shown to inhibit tumor growth in mouse melanoma and lung carcinoma models by preventing fibroblast growth factor 2 (FGF-2) binding to endothelial cells and also by removing any pre-bound FGF-2 from these cells (IC50 = ~2 μg/ml).
