Chemical constituents and coagulation activity of Syringa oblata Lindl flowers

The leaves and bark of Syringa oblata Lindl are used as folk medicine which has heat-clearing, detoxifying, dampness-removing and jaundice-relieving effects. There are many studies about leaves of S. oblata because of its abundant resource, however, less reports about the components of S. oblata flowers. The previous studies on S. oblate flowers were mainly focused on the volatile components and its traditional pharmacological activity. Thus, this study aimed to investigate the nonvolatile chemical constituents and the coagulation activity of S. oblate flowers. The chemical constituents of S. oblate flowers were isolated with various column chromatographies and coagulation activity of the major constituents was investigated by assaying the activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT) and fibrinogen (FIB) on plasma of rabbit in vitro. Fifteen known compounds (namely compound 1-15) were isolated from S. oblata flowers. Compound 6, 10, 11 and 14 were isolated from Syringa genus for the first time. Compound 1, 2, 4, 5, 8 and 9 were isolated from the plant for the first time. The results of coagulation activity showed that water part of S. oblate flowers, lauric acid and kaempferol-rutinose significantly shorten PT (P < 0.001), TT (P < 0.001) and APTT (P < 0.001) compared with blank group, thus revealed that water extract of S. oblate flowers, lauric acid and kaempferol-rutinose possessed the procoagulant activity, but the effects were not better than that of Yunnan Baiyao as positive control.