Discovery And Synthesis A Novel Benzopyran Derivatives As Potent And Selective Inhibitors For PI3K

Tumor has taken the second place in human mortality for many years,only less than cardiovascular diseases.The cytotoxic drugs such as alkylating agents and antimetabolites will inevitably suffer from disadvantages such as poor therapeutic effect,toxicity and side effects due to directly interact with mitosis,DNA synthesis and repair system.In recent years,with the development of molecular biology,the key intracellular signaling pathways and the effects of biological macromolecules such as kinases and membrane receptors have been revealed,providing an excellent direction for designing a new generation of anti-tumor drugs.Phosphatidylinositol 3-kinase(PI3K)is a key kinase involved in many cell activities such as cell growth,proliferation,metastasis,and apoptosis.Studies have shown that it plays a vital role in tumorigenesis.Thus,PI3K and its downstream kinases Akt eventually become a new target for antitumor drug development.Based on the concept of computer aided drug design(CADD)and structure-based drug design,31 compounds were designed and synthesized targeting PI3Kα.These structures were analyzed by nuclear magnetic resonance,and some relating biological activity assays were performed in vitro.Finally,we got the most potential compound A29,this research can be briefly summarized as followed:Based on the structural characteristics of the first-generation inhibitors of PI3Kα,Wortmannin and LY294002,and some literatures concerning PI3K,a series of compounds with benzopyrone as the basic nucleus were designed and synthesized.The thiazolidinedione structural fragment was introduced on the nucleus.Based on the computer virtual docking results,an alkyl and benzylic fragment were introduced at the NH position on the thiazolidinedione ring,and 31 coumarin-based derivatives were synthesized.The structures of these compounds were tested and queried using NMR and SciFinder,all of which are new compounds.Firstly,31 compounds were screened for anti-proliferative activity in HeLa,HCT-116,A549,HT29 and MCF-7 cell lines.The results showed that a considerable part of compounds superior to the positive control drug LY294002,in which the IC50 values of compounds A28 and A29 were 0.24±0.13 μM and 0.18±0.20 μM and LY294002 was 30.29±0.92 μM,respectively.Moreover,it is found that they exhibit stronger inhibitory activity against HT29 cell lines.Compared with the rest compounds,benzyl-containing ones show higher alkyl-containing ratios indicated by structure-activity relationship studies analysis.The results showed that compounds with a higher antiproliferation activity once halogen or electron-withdrawing substituent introduced into the benzyl group.Meanwhile,it also provides the evidence that morpholine ring is an essential group for the activity in such kinds compounds with a coumarin skeleton.In vitro,the dates of kinase inhibition are highly consistent with the IC50 value of anti-tumor cell proliferation.Compound A29(IC50=0.08 μM)is a kind of selective for PI3Ka.Apoptosis assay shows that compound A29 effectively induces HT29 cells apoptosis in a dose-dependent manner and Western blot experiments shows that the phosphorylation of PI3K kinase downstream protein Akt could be significantly inhibited after the treatment of A29.To verify the underlying mechanism of A29 and the PI3K inhibition,we use the compound and PI3Ka protein crystals(PDB:3HHM)for molecular docking and the results shows that the binding mode of compound A29 and PI3Ka protein crystals is similarity to LY294002,which confirms coumarin being a promising structure to design PI3K inhibitors.Based on the above results,we can conclude that compound A29 is the most potential compound as a small molecule inhibitor targeting PI3K kinase with excellent anti-tumor cell proliferation,providing guidance for further research.The coumarin derivatives designed targeting PI3Ka and binding model with its protein crystal conducted by this research could provide comprehension for subsequent development of novel PI3K inhibitors.