Yi Zhang,Chen Chen,Ya-Long Zhang,Ling-Yi Kong,Jian-Guang Luo
The reactivity-based screening (RBS) was developed for directed discovery of cytotoxic withanolides. In this study, a thiol probe, 4-chlorobenzenethiol, was used to selectively attack cytotoxic withanolides containing potential pharmacophore, 2(3)-en-1-one in ring A (AEO) and 5β , 6β -epoxy in ring B (BE), from the plant extract of Physalis angulata var. villosa . The screening was performed based on the potential mechanism of 4-chlorobenzenethiol nucleophilic addition to AEO, followed by detection of adducts using liquid chromatography quadrupole-time-of-flight mass spectrometry (LC-Q-TOF-MS). Guided by RBS, eleven target withanolides, including five new compounds, physagulides R-V ( 10 – 14 ) and six known ones ( 2 , 7 – 9 , 15 , 16 ) were discovered. All of them exhibited cytotoxicity against the both tested cell lines, especially, compounds 2 , 7 , 8 and 14 showed potent activities with IC 50 values of 1.57–6.29 μM. The results suggested that RBS was efficient and accurate for rapid identification of cytotoxic withanolides and could guide isolation of target components from the complex medicinal plant extract.
The glucose transporter 1 (GLUT1) protein is involved in the basal-level absorption of glucose in tumor cells. Inhibiting GLUT1 decreases tumor cell proliferation and induces tumor cell damage. Natural GLUT1 inhibitors have been studied only to a small extent, and the structures of known natural GLUT1 inhibitors are limited to a few classes of natural products. Therefore, discovering and researching other natural GLUT1 inhibitors with novel scaffolds are essential. Physalis angulata L. var. villosa is a plant known as Mao-Ku-Zhi (MKZ). Withanolides are the main phytochemical components of MKZ. MKZ extracts and the components of MKZ exhibited antitumor activity in recent pharmacological studies. However, the antitumor-active components of MKZ and their molecular mechanisms remain unknown. A cell membrane-biomimetic nanoplatform (CM@Fe3O4/MIL-101) was used for target separation of potential GLUT1 inhibitors from MKZ. A new withanolide, physagulide Y (2), together with six known withanolides (1, 3–7), was identified as a potential GLUT1 inhibitor. Physagulide Y was the most potent GLUT1 inhibitor, and its antitumor activity and possible mechanism of action were explored in MCF-7 human cancer cells. These findings advance the development of technologies for the targeted separation of natural products and identify a new molecular framework for the investigation of natural GLUT1 inhibitors.
危险品化学品经营许可证（带存储）