Camellianols A–G, Barrigenol-like Triterpenoids with PTP1B Inhibitory Effects from the Endangered Ornamental Plant Camellia crapnelliana

Seven new naturally occurring barrigenol-like compounds, camellianols A–G (1–7), and 10 known triterpenoids were isolated from the twigs and leaves of the cultivated endangered ornamental plant Camellia crapnelliana. According to the ECD octant rule for saturated cyclohexanones, the absolute configurations of camellianols D (4) and E (5) were defined. The backbones of the remaining new isolates are assumed to have the same absolute configuration as compounds 4, 5, and harpullone (12). Compounds 2, 3, 9, 10, 13, and 16 exhibited inhibitory effects on the protein tyrosine phosphatase 1B (PTP1B) enzyme, with IC50 values less than 10 μM.

从栽培的濒危观赏植物红皮糙果茶（Camellia crapnelliana）的枝条与叶片中，分离得到7个全新天然巴戟醇类类似物——山茶醇A–G（化合物1–7）以及10个已知三萜类化合物。基于饱和环己酮类化合物的电子圆二色谱（Electronic Circular Dichroism, ECD）八区规则，确定了山茶醇D（化合物4）与山茶醇E（化合物5）的绝对构型。其余新分离得到的化合物，其骨架的绝对构型被推定与化合物4、5以及harpullone（化合物12）一致。化合物2、3、9、10、13与16对蛋白酪氨酸磷酸酶1B（Protein Tyrosine Phosphatase 1B, PTP1B）具有抑制活性，其半数抑制浓度（IC50）均低于10 μM。