TRITERPENES FROM MICONIA LANGSDORFFII AND EVALUATION OF SCHISTOSOMICIDAL ACTIVITY

Neglected diseases affect thousands of people worldwide and lack adequate treatments, remaining one of the major public health problems and requiring new therapeutic alternatives. Among neglected diseases, schistosomiasis caused by the parasite Schistosoma mansoni stands out. Different chemical classes obtained from natural products have given rise to several drugs across therapeutic categories. In the present study, phytochemical investigations and the evaluation of the schistosomicidal activity of the crude hydroalcoholic extract from the aerial parts of Miconia langsdorffii are reported. The fractions obtained from extract fractionation were biomonitored for schistosomicidal activity. Fraction F2 was the most promising, showing 100% separated worm pairs, 100% high reduction in motor activity within only 24 hours, and 100% parasite mortality after 120 hours of incubation. In this fraction, a mixture of the triterpenes ursolic acid and oleanolic acid was identified. These triterpenes were isolated by HPLC and also evaluated. The mixture of the two triterpenes was able to potentiate schistosomicidal activity, thus demonstrating a possible synergistic effect. Ursolic acid showed better results when compared to oleanolic acid and, for this reason, aiming at a possible enhancement of activity, five semisynthetic derivatives were prepared. Among these derivatives, the potassium salt derivative of ursolic acid stood out, being the only one that potentiated the activity with 100% separated worm pairs after 120 hours of incubation, compared to ursolic acid, which showed 50% under the same conditions.