Protease inhibitor. Inhibitor of serine proteinases having a chymotrypsin-like specificity like α-, β-, δ- and γ-chymotrypsin, chymases, cathepsin G, and most cysteine proteinases including papain and cathepsin A, B, H, and L. Mixture of type A (R=L-Leu), type B (R=L-Val), type C (R=L-Ile). Alternative name: (S)-1-Carboxy-2-phenylethyl)-carbamoyl-alpha-[2-iminohexahydro-4(S)-pyrimidyl]-(S)-glycyl-X-phenylalaninal. Formula: C21H38N4O8. MW: 605.0 (average). Solubility: Soluble in DMSO (20mg/ml) or glacial acetic acid. Long Term Storage: -20°C.