RESUMO
Sulfated derivatives of xylan (isolated from Bétula pubéscens wood) with average molecular weight ~34 kDa, sulfur content of 11.3-17.5%, a degree of substitution of 0.74-1.64 are anticoagulants of direct type of action. Antithrombin and antifactor Xa activities in three tested xylan samples did not differ and reached 30.8-31.8 and 13.5-14.3 U/mg, respectively.
Assuntos
Anticoagulantes/farmacologia , Fator Xa/metabolismo , Trombina/antagonistas & inibidores , Xilanos/farmacologia , Anticoagulantes/química , Anticoagulantes/isolamento & purificação , Betula/química , Coagulação Sanguínea/efeitos dos fármacos , Testes de Coagulação Sanguínea , Humanos , Peso Molecular , Extratos Vegetais/química , Sulfatos/química , Trombina/metabolismo , Xilanos/química , Xilanos/isolamento & purificaçãoRESUMO
Betulin and its esters are the natural compounds with high in vitro cytotoxicity toward many cancer cells. However, the poor water solubility of these compounds has limited their applications. We prepared new composites of betulin esters using two methods, namely ball-milling of the mixtures of betulin esters with arabinogalactan and preparation of thin films of these mixtures by evaporating the aqueous solutions. These composites revealed higher water solubility as compared with the initial substances without losing the structural integrity and functionality. As a result, the new composites have shown much higher inhibitory effects against different cancer cell lines such as Ehrlich ascites carcinoma cells and lung carcinoma cells (A549) in comparison with the initial substances. The cell viability studies based on Annexin V and Propidium iodide probes have confirmed the high proapoptotic effect of betulin ester derivatives against cancer cells.