Ligand Design of 5,5'-Diphenylimidazolidine-2,4-dione Analogues as A New Class of Potent Inhibitors of Fatty Acid Amide Hydrolase

3D-QSARs (3 dimensional quantitative structrue-activity relationships) on the inhibition activities of 3-substituted-5,5'-diphenylimidazolidine-2,4-dione derivatives (1-22) against FAAH (fatty acid amide hydrolase) were studied quantitatively using CoMFA (comparative molecular field analysis) and CoMSIA (comparative molecular similarity indice analysis) methods. The statistical results of the CoMFA 1A and CoMSIA 2F model are better predictability and fitness. And also, the designed X=I, Y=N-2(+)-substituent (P1: Pred.pI(50)=6.55), according to the contour maps with information of the two models, showed the most inhibition activity against FAAH.