Syntheses, Crystal Structures and Anticoagulant Activities of Two L-tryptophan Derivatives

Two new L-tryptophan derivatives, (S)-2-(4-acetoxybenzamido)-3-(1H-indol-3- yl) propanoic acid (I) and (S)-2-(3-acetoxybenzamido)-3-(1H-indol-3-yl) propanoic acid (II), were synthesized and characterized by FT-IR, NMR and MS. The single crystals were cultivated and determined with X-ray diffraction. It was determined that the two compounds crystallized in monoclinic space group P2(1). Compound I (C21H20N2O5, M-r = 380.39) with a = 8.5227(6), b = 7.8310(6), c = 15.2527(11) angstrom, Z = 2, V = 1017.81(13) angstrom(3), mu = 0.090 mm(-1), D-c = 1.241 g/cm(3), F(000) = 400, the final R = 0.0412 and R-w = 0.1170 for all data. Compound II (C21H20N2O5, M-r = 380.39) with a = 9.5112(5), b = 9.2197(4), c = 10.9115(5) angstrom, Z = 2, V = 952.13(8) angstrom(3), mu = 0.096 mm(-1), D-c = 1.327 g/cm(3), F(000) = 400, the final R = 0.0377 and R-w = 0.1009 for all data. The anticoagulant activities of L-tryptophan derivatives were evaluated by plasma re-calcification time (PRT) and blood concretion four items (APTT, PT, TT and FIB). The results exhibited that L-tryptophan derivatives showed anticoagulant activity in normal coagulation pathway.