An ethanolic extract of Antiaris toxicaria trunk bark showed potent in vitro cardiotonic effect on isolated guinea pig atria. Bioassay-guided fractionation of the extract led to identification of nine new cardiac glycosides (1−9, named antiarosides A−I), antiarotoxinin A (10), and 18 known compounds. Their structures were established using MS and NMR spectroscopic studies, including homonuclear and heteronuclear correlation experiments. The ability of these cardiotonic compounds to produce positive inotropic action and their safety indexes were examined in comparison with those of ouabain, a classical inhibitor of Na⁺/K⁺-ATPase. Malayoside (23) was nearly equipotent and had a similar safety index to ouabain in guinea pig atria. However, the maximal positive inotropic effect and safety index of 23 in papillary muscle were better than those of ouabain. An electrophysiological recording showed that 23 inhibited the sodium pump current in a concentration-dependent manner.

中文翻译：

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来自具有强心强心活性的毒螟的心脏糖苷

Antiaristoxicaria树干树皮的乙醇提取物对离体的豚鼠心房显示出有效的体外强心作用。导致的九个新的强心苷（识别提取物的生物测定引导的分级分离1 - 9，名为antiarosides A-I）中，antiarotoxinin A（10），和18种已知的化合物。它们的结构是使用 MS 和 NMR 光谱研究确定的，包括同核和异核相关实验。将这些强心化合物产生正性肌力作用的能力及其安全指数与哇巴因（Na ⁺ /K ⁺ -ATPase的经典抑制剂）进行比较。马来苷 ( 23) 在豚鼠心房中几乎是等效的，并且具有与哇巴因相似的安全指数。但乳头肌最大正性肌力作用和安全指数23优于哇巴因。电生理记录显示，23以浓度依赖性方式抑制钠泵电流。