Biological Activity
s3i-201 is a selective inhibitor of stat3 with ic50 value of 86 μm [1].in the in vitro stat3 dna-binding assay, s3i-201 showed potent inhibition of the stat3 dna-binding activity with an average ic50 of 86 μm. in the emsa assay, s3i-201 selectively inhibited stat3 dna-binding activity over that of stat1 and stat5. it suppressed the complex formation of stat1-stat3 and stat1-stat1 with ic50 values of 160 and > 300 μm, respectively. besides that, the unphosphorylated, inactive stat3 monomer was found to restore the stat3 dna-binding activity inhibited by s3i-201, suggesting that the inhibition was independent on the activation status. in nih 3t3/v-src fibroblasts, s3i-201 inhibited the constitutive activation of stat3 and reduced the ptyr-705 stat3 levels. moreover, s3i-201 was found to significantly induce apoptosis in cells with constitutively active stat3 at concentration of 30–100 μm. s3i-201 also reduced the expression of cyclin d1, bcl-xl and surviving in these cells [1].
Synthesis
A mixture of 7-aminosalicylic acid (102 mg, 0.67 mmol) with NaOH (27 mg, 0.67 mmol) in water (6 mL) was stirred at room temperature for 10 min until completely dissolved, using 7-aminosalicylic acid (102 mg, 0.67 mmol) as starting material. Na2CO3 (59 mg, 0.5561 mmol) was then added and the mixture was cooled to 0 °C. A solution of THF (2 mL) of 2-chloro-2-oxoethyl-4-methylbenzenesulfonate (200 mg, 0.8044 mmol) was quickly added, and the reaction system was gradually warmed to room temperature and stirred continuously for 2 hours. Upon completion of the reaction, the mixture was transferred to a partition funnel containing ether for phase separation. After the aqueous phase was washed with another portion of ether, the pH was adjusted to 1 by dropwise addition of 1N HCl solution and the product was subsequently extracted with ethyl acetate. The ethyl acetate phase was washed twice sequentially with 1N HCl solution, dried over Na2SO4, filtered and concentrated under reduced pressure to remove the solvent. The resulting light yellow solid was ground with chloroform to afford the target product 2-hydroxy-4-(2-(tolylsulfonyloxy)acetylamino)benzoic acid (155 mg, 63% yield) in white powder form. The product characterization data were as follows: 1H NMR (400 MHz, DMSO) δ 2.37 (3H, s, Me), 4.68 (2H, s, CH2), 6.93 (1H, d, J = 7.4 Hz, ArH), 7.17 (1H, s, ArH), 7.46 (2H, d, J = 6.8 Hz, ArH), 7.69 (1H, d, J = 7.4 Hz, ArH), 7.81 (2H, d, J = 6.8 Hz, ArH), 10.32 (1H, s, NH); 13C NMR (100.6 MHz, DMSO) δ 21.8, 68.0, 107.0, 110.7, 128.5, 130.9, 131.7, 132.7, 144.5, 146.0, 162.8, 164.8, 164.0, 166.0, 162.8, 164.8, 164.0, 166.0, 166.0, 164.0 162.8, 164.5, 172.2; MS (ES+) m/z 366.0 ([M + H]+, 100%), 388.0 ([M + Na]+, 50%); no signal detected in the negative ion mode.
References
[1] siddiquee k, zhang s, guida w c, et al. selective chemical probe inhibitor of stat3, identified through structure-based virtual screening, induces antitumor activity. proceedings of the national academy of sciences, 2007, 104(18): 7391-7396.
![Acetyl chloride, 2-[[(4-methylphenyl)sulfonyl]oxy]-](/CAS/20200611/GIF/54150-49-1.gif)
