As STAT3 has been validated as an anticancer target, its inhibitors have been shown to possess therapeutic promise for the treatment of human cancers. To identify novel and selective STAT3 inhibitors, a virtual screening based on the STAT3 SH2 domain was performed and a small molecule, 2-phenylquinoline-4-carboxylic acid (5a), with an inhibition constant Ki value of 17.53 μM to STAT3 was discovered. On this basis, the derivatives of ...