Synthesis Of 2-Phenyl-1H-benzimidazole Structural Analogs And Study On The Mechanism Of Interaction With FTO Protein

FTO(fat mass and obesity-associated)is a gene associated with obesity risk.Studies have found that abnormally expressed FTO protein plays a role in promoting cancer in some tumors,such as leukemia,lung cancer,breast cancer,etc.Therefore,the study of FTO protein small molecule inhibitors has become a hotspot in recent years.On the basis of the previous research of our group,using 2-phenyl-1Hbenzimidazole as the parent ring,several structural analogs were designed by molecular docking.Then thirty 2-phenyl-1 H-benzimidazole structural analogs with strong binding to FTO protein were synthesized,their structures were characterized by means of 1H NMR,13C NMR and MS,and their mechanism of action and binding affinity with FTO protein were explored.The experimental results of UV-visible absorption spectra showed that the 2phenyl-1H-benzimidazole structural analogs all changed the absorption peak of FTO protein at 280 1m.It was preliminarily judged that these thirty compounds interacted with FTO protein,thirty compounds may have interacted with the FTO protein.Compounds 9,11,13,14,18,19,22,23,24,25,26,and 28 shifted the position of the UV absorption peak of FTO protein around 280 nm.Fluorescence spectroscopy experiments showed that thirty kinds of 2-phenyl-1Hbenzimidazole structural analogs all had different degrees of quenching on the fluorescence of FTO protein.Thirty 2-phenyl-1H-benzimidazole structural analogs have strong binding ability to FTO protein by comparing the binding constant and the number of binding sites.The order of binding affinity is:28>23>24>9>13>11>26>14>29>25>21>7>12>10>30>4>27>15>8>20>2>19>5>1>6>22>16>3>17>18.Thermodynamic results showed that the main types of interaction between 2-phenyl-lH-benzimidazole structural analogs(1,3,4,11,15,19,21)and FTO protein are hydrophobic and electrostatic forces,the other twenty-three compounds interact with FTO protein mainly by hydrogen bond or van der Waals force.We selected six 2-phenyl-lH-benzimidazole structural analogs with the strongest binding ability to FTO protein,and studied their effect on the conformation of FTO protein,the numbers are 28,24,23,9,13,11.The results of spectroscopic experiments showed that these six compounds all weakened the hydrophobicity of FTO protein.Cytotoxicity studies were performed using the CCK-8 method,thirty 2-phenyl1H-benzimidazole structural analogs were screened for activity.The results showed that compounds 26 and 23 had better inhibitory effect on the proliferation of leukemia cell K562,with IC50 values of 14.65 μmol/L and 18.11 μmol/L,respectively.