16 research outputs found
Not all farms are created equal: Shady African cocoa farms promote a richer bat fauna
Bats provide important pest suppression services with economic value to cocoa farmers, yet the impact of cocoa farm management on bat diversity metrics is still poorly understood. This is especially important if we consider that Afrotropical cocoa farms supply 68 % of the world's chocolate market, with expected increases in production in the forthcoming decades. In this study, we investigated for the first time how bat abundance, richness and diversity varied between African cocoa farms with different levels of shade tree cover, shade tree communities and cocoa characteristics. We found that shade tree cover and shade tree height were the main drivers associated with an increase of Shannon diversity, and abundance and richness of insectivores. Frugivorous and nectarivorous bats were positively associated with the presence of planted shade trees, but richness varied with the size of shade trees. The insectivorous Hipposideros fuliginosus was only present in high shade farms, being captured 51 times only in this shade system, while the frugivorous Myonycteris angolensis was associated with low shade farms. Our findings show that indeed not all farms are created equal, with high shade farms with large, tall forest shade trees (i.e., containing key plant resources) having richer bat communities. Therefore, policymakers seeking to conserve wildlife within cocoa farming systems should adopt cocoa management systems like those mentioned above and promote a combination of forest and planted shade trees to be able support a rich community of insectivorous, frugivorous and nectarivorous bats and maintain their associated ecosystems services
Synthesis of lupeol derivatives and their antileishmanial and antitrypanosomal activities
Synthesis of lupeol derivatives and their antileishmanial and antitrypanosomal activities
<p>The natural product lupeol <b>1</b> was isolated from aerial parts of <i>Vernonia scorpioides</i> with satisfactory yield, which made it viable to be used as starting material in semisynthetic approach. Ten lupeol derivatives <b>2–11</b> were prepared by classical procedures. Including, five new esters derivatives <b>7–11,</b> which were obtained by structural modifications in the isopropylidene fragment. All semisynthetic compounds and lupeol <b>1–11</b> were confirmed by <sup>1</sup>H NMR, <sup>13</sup>C NMR and HRMS. Their antiprotozoal activity was evaluated <i>in vitro</i> against <i>L. amazonensis</i> and <i>T. cruzi.</i> Derivative <b>6</b> showed the best antitrypanosomal activity (IC<sub>50</sub> = 12.48 μg/mL) and the lowest cytotoxic derivative (CC<sub>50</sub> = 161.50 μg/mL). The mechanism of action of the most active derivatives (<b>4, 6</b> and <b>11</b>) is not dependent from the enzyme trypanothione reductase.</p