A New<i>in vitro</i>Tissue Factor Inhibitory Triterpene from the Fruits of<i>Chaenomeles sinensis</i>

Abstract

Tissue factor (TF, tissue thromboplastin) accelerates the blood clotting, activating both the intrinsic and the extrinsic pathways to serve as a cofactor. In order to isolate TF inhibitors from the fruits of Chaenomeles sinensis, an activity-guided purification was carried out to yield four triterpenoid compounds. One compound was new and its structure was elucidated as 28-O-beta- D-glucopyranosyl-2alpha,3beta-dihydroxyolean-12-ene-24,28-dioic acid (2), named chaenomeloside A by means of spectral analysis and chemical conversion. Other compounds were trachelosperoside A-1 (1), oleanolic acid (3) and ursolic acid (4). Compound 2 and its aglycone 2a, named chaenomelogenin A inhibited by 50 % the TF activity at concentrations of 0.036 and 0.028 mM/unit of TF, respectively. Compound 1 isolated for the first time from this plant as well as 3 and 4 were inactive.