Four undescribed 23,24-O-isopropylidene-19(18 → 17)-abeo-28-noroleanane-derived spirocyclic triterpenoids and an undescribed 28-noroleanane-derived spirocyclic triterpenoid, together with five known 28-noroleanane-derived spirocyclic triterpenoids, were isolated and identified. In addition, three undescribed iridoid glucosides and four known ones were also identified. All the isolates were identified using spectroscopic techniques, and the absolute configurations of 28-noroleanane-derived spirocyclic triterpenoids were determined by CD method for the first time. Additionally, the alkaline hydrolysis method and HPLC analysis were applied to confirm the moieties of the iridoid glucosides. The fraction and isolates were evaluated for cytotoxic activity on cervical cancer (Hela), human promyelocytic leukemia (HL-60), and breast cancer (MCF-7) cell lines. Among them, phlomisu E possessed an aldehyde group showed the most potent cytotoxic effect with IC50 value less than 10 μM.

中文翻译：

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来自 Phlomoides umbrosa (Turcz.) Kamelin & Makhm 根的 28-Noroleanane 衍生的螺环三萜和环烯醚萜苷及其细胞毒作用

四种未描述的 23,24-O-isopropylidene-19(18 → 17)-abeo-28-noroleanane 衍生的螺环三萜和一种未描述的 28-noroleanane 衍生的螺环三萜，以及五种已知的 28-noroleanane 衍生的螺环三萜隔离和识别。此外，还鉴定了三种未描述的环烯醚萜苷和四种已知的。所有分离株均采用光谱技术进行鉴定，并首次采用CD法测定了28-降油菜烷衍生的螺环三萜的绝对构型。此外，还应用碱水解法和 HPLC 分析来确认环烯醚萜苷的组成部分。评估级分和分离物对宫颈癌 (Hela)、人早幼粒细胞白血病 (HL-60)、和乳腺癌 (MCF-7) 细胞系。其中，具有醛基的 phlomisu E 表现出最强的细胞毒作用，IC50 值小于 10 μM。