State Key Laboratory of Phytochemistry and Plant Resources in West China, and Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China.
State Key Laboratory of Phytochemistry and Plant Resources in West China, and Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, PR China.
Phytochemistry. 2021 Jun;186:112731. doi: 10.1016/j.phytochem.2021.112731. Epub 2021 Mar 13.
The Lamiaceae plant Ajuga forrestii Diels is a traditional Chinese herbal medicine with abundant glandular trichomes (GTs), but their chemistry and biological functions remain uninvestigated. Here, a panel of six highly functionalized neo-clerodane diterpenoids was localized to the peltate GTs of A. forrestii using laser microdissection coupled with HPLC analysis, indicating that the GTs of A. forrestii are an excellent material for the elucidation of the yet unclear biosynthetic pathway of natural neo-clerodane diterpenoids. In addition, four undescribed neo-clerodane diterpenoids with an acyclic C-9 side chain including two pairs of 1:1 mixture of inseparable diastereomers, ajuforrestins D-G, were isolated from the fresh leaves of A. forrestii together with six known compounds. The structures of the undescribed compounds were elucidated by spectroscopic (including 1D and 2D NMR and HR-ESI-MS) analyses. Biological assays indicated that the major GT compound ajugacumbin B and undescribed ajuforrestins D/E showed antifeedant activity against Helicoverpa armigera, suggesting that neo-clerodanes in A. forrestii should be involved in plant defence against insects. Moreover, the abietane diterpenoid ajuforrestin B exhibited significant anti-inflammatory activity on the secretion of interleukin-2 (IL-2) and cytotoxicity against three cancer cell lines, NCI-H1975, HepG2 and MCF-7, suggesting that ajuforrestin B could positively contribute to the therapeutic effects of this traditional Chinese medicine.
唇形科筋骨草属植物筋骨草 Ajuga forrestii Diels 是一种传统的中草药，其腺毛（GTs）丰富，但它们的化学和生物功能尚未得到研究。在这里，使用激光显微切割与 HPLC 分析，将一组六种高度功能化的新蛇麻烷二萜类化合物定位到筋骨草 A. forrestii 的盾状 GTs 中，这表明 A. forrestii 的 GTs 是阐明新蛇麻烷二萜类天然生物合成途径的绝佳材料。此外，从筋骨草 A. forrestii 的新鲜叶片中分离出了四个未描述的具有非环 C-9 侧链的新蛇麻烷二萜类化合物，包括两对不可分离的非对映异构体的 1:1 混合物 ajuforrestins D-G，以及六个已知化合物。通过光谱（包括 1D 和 2D NMR 和 HR-ESI-MS）分析阐明了未知化合物的结构。生物测定表明，主要的 GT 化合物 ajugacumbin B 和未描述的 ajuforrestins D/E 对棉铃虫具有抗取食活性，表明筋骨草中的新蛇麻烷类化合物应该参与了植物对昆虫的防御。此外，扁柏烷二萜 ajuforrestin B 对白细胞介素-2（IL-2）的分泌具有显著的抗炎活性，对三种癌细胞系 NCI-H1975、HepG2 和 MCF-7 具有细胞毒性，表明 ajuforrestin B 可能对这种中药的治疗效果有积极贡献。
