A series of Sodium 4-[(4-butoxyphenyl) thio]-2′-substituted-1, 1′-biphenyl-3-sulfonates were identified as functional sphingosine-1-phosphate (S1P) antagonists with selectivity for the S1P1 receptor subtype starting from chemical lead 2, which was found while screening our in-house compound library. We performed chemical modifications on each regional structure of compound 2, for example, on the three ring compartments, the benzyl ...