Highly active and selective anticoagulants: D-Phe-Pro-Arg-H, a free tripeptide aldehyde prone to spontaneous inactivation, and its stable N-methyl derivative, D-MePhe-Pro-Arg-H - Bajusz, S; Szell, E; Bagdy, D; Barabäs, E; Horväth, Gy; Diöszegi, M; Fittier, Zs; Szabö, G; Juhäsz, A; Tomori, E; Szilägyi, G (J Med Chem, 1990)