Antibacterial and Antiplasmodial Constituents of <i>Beilschmiedia cryptocaryoides</i>

Four new beilschmiedic acid derivatives, cryptobeilic acids A–D (<b>1</b>–<b>4</b>), and tsangibeilin B (<b>5</b>) have been isolated from the bark of <i>Beilschmiedia cryptocaryoides</i> collected from Madagascar. Their structures were elucidated using detailed spectroscopic and spectrometric methods. Cryptobeilic acid A (<b>1</b>) and tsangibeilin B (<b>5</b>) structures were confirmed by single-crystal X-ray diffraction analysis. Compounds <b>1</b>–<b>5</b> displayed moderate antibacterial activity against <i>Escherichia coli</i> 6r3, <i>Acinetobacter calcoaceticus</i> DSM 586, and <i>Pseudonamas stutzeri</i> A1501, with the minimum inhibitory concentrations ranging from 10 to 50 μM, respectively. In addition, the compounds exhibited antiplasmodial activity against erythrocytic stages of chloroquine-resistant <i>Plasmodium falciparum</i> strain NF54 and weak cytotoxicity against L6 cell lines