Six undescribed sesquiterpene glucosides, fissispallins A-F, and one known sesquiterpene glucoside, fissispallin, were discovered in the leaves of Fissistigma pallens (Finet & Gagnep.) Merr. The structures were determined using spectroscopic methods, including 1D, 2D NMR, and MS. All compounds were evaluated for cytotoxic activity against three human cancer cell lines, HT-29, A-2058, and A-549. Fissispallin A showed potent activity with the IC50 values less than 1.5 μM against all tested human cancer cell lines. Fissispallin also showed potent activity with IC50 value of 0.4 ± 0.3 on the A-2058 cancer cell lines. Fissispallins B-D showed significant cytotoxic activity against all the tested cancer cell lines with IC50 values ranging from 3.8 to 7.2 μM.

中文翻译：

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来自 Fissistigma pallens 的细胞毒性倍半萜糖苷

在 Fissistigma pallens (Finet & Gagnep.) Merr 的叶子中发现了六种未描述的倍半萜糖苷 fissispallins AF 和一种已知的倍半萜糖苷 fissispallin。使用光谱方法确定结构，包括一维、二维核磁共振和质谱。评估了所有化合物对三种人类癌细胞系 HT-29、A-2058 和 A-549 的细胞毒性活性。Fissispallin A 对所有测试的人类癌细胞系显示出有效的活性，IC50 值小于 1.5 μM。Fissispallin 对 A-2058 癌细胞系也显示出有效的活性，IC50 值为 0.4 ± 0.3。Fissispallins BD 对所有测试的癌细胞系均显示出显着的细胞毒活性，IC50 值范围为 3.8 至 7.2 μM。