Resin glycosides represent an important chemotaxonomic marker of the Convolvulaceae family and possess multidrug resistance (MDR) reversal activity. In our recent study, nine previously undescribed resin glycosides, Calonyctins B-J, were isolated from the seeds of Ipomoea muricata. Their structures with the absolute configuration were established on the basis of comprehensive spectroscopic analysis and chemical methods. Among these, Calonyctins F-I possessed a skeleton in which the aglycone moiety and the oligosaccharide core were linked by a 3-hydroxy-2-methylbutanoic acid moiety to form a 25-membered macrocyclic structure. Calonyctins E, J, and muricatic acid C methyl ester were non-cytotoxic but enhanced the cytotoxicity of vincristine by 2.5-407.1 fold at 25 μM in KB/VCR cells. Calonyctin E was the most active one.

中文翻译：

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木瓜种子中的树脂糖苷及其多药耐药逆转活性

树脂糖苷是旋花科重要的化学分类标志物，具有逆转多药耐药性 (MDR) 的活性。在我们最近的研究中，从 Ipomoea muricata 的种子中分离出了九种以前未描述的树脂糖苷 Calonyctins BJ。它们的绝对构型结构是在综合光谱分析和化学方法的基础上建立的。其中，Calonyctins FI 具有一个骨架，其中苷元部分和寡糖核心通过 3-羟基-2-甲基丁酸部分连接形成 25 元大环结构。Calonyctins E、J 和鼠尾草酸 C 甲酯没有细胞毒性，但在 KB/VCR 细胞中，25 μM 时长春新碱的细胞毒性提高了 2.5-407.1 倍。Calonyctin E 是最活跃的一种。