Chemical constituents from Sedum aizoon and their hemostatic activity

Context: Sedum aizoon L. (Crassulaceae) (SA) is widely used to treat various hemorrhages in folk medicine. However, its hemostatic constituents are not yet clear. Objective: The chemical constituents of EtOAc fraction from SA and their hemostatic activity were investigated to provide a basis for the application in folk use. Materials and methods: The chemical constituents were isolated from the aerial parts of SA by column chromatography and identified by IR, MS, and NMR, then tested for hemostatic activity using the capillary method and coagulation assays including blood clotting time in vivo, and prothrombin time (PT), activated partial thromboplastin time (APTT), and thrombin time (TT) in vitro at concentrations of 300.0, 100.0, and 30.0 mu g/mL. Results: Eleven compounds were identified as p-hydroxybenzoic acid (1), gallic acid (2), protocatechuic acid (3), vallinic acid (4), thymine (5), caffeic acid (6), 5,7-dihydroxy chromone (7), pyrogallol (8), quercetin (9), kaempferol (10), and luteolin (11). This is the first report of compounds 3-8 being isolated from this plant. Compounds 2 (300.0 and 100.0 mg/mL), 4 (100.0 mg/mL), and 11 (100.0 and 30.0 mg/mL) significantly reduced the clotting time (p < 0.01) with inhibition rates of 34.7, 24.5, 30.3, 25.9, and 36.6%, respectively. For further mechanism study, they also reduced PT (3.5, 2.5, 3.5, 3.5, and 3.8%, respectively), APTT (4.5, 3.3, 11.4, 8.5, and 11.1%, respectively), and TT (20.3, 3.8, 7.6, 6.1, and 10.3%, respectively). Discussion and conclusion: SA produced hemostatic activity possibly related to the presence of gallic acid, vallinic acid, and luteolin, which may be potent candidates of hemostatic drug.