Three undescribed seco-ursane stereoisomers, ilexcornutosides A-C, two undescribed triterpenoid saponins, ilexcornutosides D-E, and 11 known triterpenoids were isolated from the leaves of Ilex cornuta Lindl. & Paxton. Ilexcornutosides A-C and F with the same planar structures are unique 13(18)-ene-18,19-seco-ursane skeleton triterpenoids, identified as (3S,12R)-3-O-[β-d-glucopyranosyl-(1 → 2)-α-l-arabinopyranosyl]-12-hydroxyl-19-oxo-18,19-secours-13(18)-en-28,21-lactone. Among them, ilexcornutosides A and F (or ilexcornutosides B and C) are a pair of diastereomers at the C-20 position; ilexcornutosides A and C (or ilexcornutosides B and F) are a pair of diastereomers with epimerization at the C-21. Their structures were established by extensive spectroscopic (IR, 1D and 2D NMR, and HR-ESI-MS) and chemical analyses. The absolute configurations of ilexcornutosides A, B, D and F were determined by a single crystal X-ray diffraction analysis with a Cu Kα radiation. The inhibitory effect of ilexcornutosides A-F on the PPARγ expression was assessed in the 3T3-L1-Lenti-PPARγ-Luc cells using a single luciferase reporter assay. Ilexcornutosides A and C showed a comparable activity in decrease of the PPARγ expression to the positive control (T0070907) at 5 μM.

中文翻译：

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来自冬青叶的抗脂肪生成 18,19-seco-ursane 立体异构体和齐墩果型皂苷

从冬青属植物 Lindl 的叶子中分离出三种未描述的二十二烷醚立体异构体、冬青树苷 AC、两种未描述的三萜皂苷、冬青苷 DE 和 11 种已知的三萜类化合物。＆帕克斯顿。具有相同平面结构的冬青果苷 AC 和 F 是独特的 13(18)-ene-18,19-seco-ursane 骨架三萜类化合物，鉴定为 (3S,12R)-3-O-[β-d-吡喃葡萄糖基-(1 → 2)-α-1-阿拉伯吡喃糖基]-12-羟基-19-氧代-18,19-secours-13(18)-en-28,21-内酯。其中，冬青苷A和F（或冬青苷B和C）是C-20位的一对非对映异构体；ilexcornutosides A 和 C（或 ilexcornutosides B 和 F）是一对在 C-21 处差向异构化的非对映异构体。它们的结构是通过广泛的光谱（IR、1D 和 2D NMR，以及 HR-ESI-MS）和化学分析确定的。通过使用 Cu Kα 辐射的单晶 X 射线衍射分析确定 ilexcornutosides A、B、D 和 F 的绝对构型。在 3T3-L1-Lenti-PPARγ-Luc 细胞中使用单一荧光素酶报告基因检测评估了冬青豆苷 AF 对 PPARγ 表达的抑制作用。Ilexcornutosides A 和 C 在降低 PPARγ 表达方面表现出与 5 μM 的阳性对照 (T0070907) 相当的活性。