Purity >95%. Fudosteine is a cysteine derivative that interferes with the increase in goblet cell number, expression of the mucin MUC5AC, and subsequent mucin secretion, in airways agonized with tobacco smoke, isoproterenol, lipopolysaccharide, TNF-Alpha, or oxidants. Fudosteine, which is a thiol compound with antioxidant properties, limits NF-?B signaling and reduces inflammatory gene expression. It has greater bioavailability than N-acetyl-cysteine and increases cysteine levels in cells.