Enantioselective syntheses and application of 4-<i>epi</i>-galiellalactone and the corresponding activity-based probe: from strained bicycles to strained tricycles
作者:Yandong Lu、Shan Zhao、Shijie Zhou、Si-Cong Chen、Tuoping Luo
DOI:10.1039/c8ob01915k
日期:——
inhibitor for Signal Transducer and Activator of Transcription 3 (STAT3). Recognizing the ring strain associated with the skeleton of this natural product, we utilized 1R-5S-bicyclo[3.1.0]hexan-2-one as the starting material and developed two novel approaches to accomplish the enantioselective total synthesis of the C4 epimer of galiellalactone in 5 and 7 steps, respectively, which capitalized on an
[6,5,5]三环真菌代谢产物galiellalactone是Michael受体,已被证明是信号转导子和转录激活因子3(STAT3)的共价抑制剂。认识到与该天然产物的骨架有关的环应变,我们以1 R -5 S-双环[3.1.0]己二-2-酮为原料,开发了两种新颖的方法来完成C4的对映选择性全合成galiellalactone的差向异构体分别在5个步骤和7个步骤中进行,利用了有效的自由基环化/片段化级联反应。此外,基于活动的4- Epi探针成功制备了带有末端炔烃标签的β-半乳糖苷,以进行基于活性的蛋白谱分析(ABPP)。通过蛋白质印迹和蛋白质组学分析,我们不仅确认了已知的靶标STAT3,而且还鉴定了新的靶标蛋白紫杉素7,它通过Cys-129残基与探针在完整细胞中形成共价键。