A series of 2,3-dioxoindolin-N-phenylacetamide derivatives was evaluated for inhibitory activity against CDC25B and PTP1B enzymes. Most of the derivatives showed inhibitory activity against CDC25B (IC50 = 3.2-23.2 µg/mL) and PTP1B (IC50 = 2.9-21.4 µg/mL). Compound 2h showed the most inhibitory activity in vitro with IC50 values of 3.2 and 2.9 µg/mL against CDC25B and PTP1B, respectively, compared with the reference drugs Na3VO4 (IC50 = 2.7 µg/mL) and oleanolic acid (IC50 = 2.3 µg/mL). The results of selectivity experiments showed that the 2,3-dioxoindolin-N-phenylacetamide derivatives were selective inhibitors against CDC25B and PTP1B. Enzyme kinetic experiments demonstrated that compound 2h was a specific inhibitor with the typical characteristics of a mixed inhibitor. In cytotoxic activity assays compound 2h had potent activity against A549, HeLa, and HCT116 cell lines. In addition, compound 2h showed potent tumor inhibitory activity in a colo205 xenograft model in vivo.

New glassy carbon electrode (GCE) modified with carboxyl multiwalled carbon nanotubes (MWCNTs) and treated with ultrasonic dispersing in N,N-dimethylfomamide (DMF) media, namely DMF/carboxyl/MWCNTs/GCE, was prepared for electrochemical determination of sulfonamides (SAs). Electrochemical behavior of SAs based on DMF/carboxyl/MWCNTs/GCE was investigated by cyclic voltammetry and impedance spectroscopy. The effects of various experimental parameters on the response of electrode such as pH of buffer, scan rate and the amount of modification were optimized. Under the optimal conditions, the obtained sensor presented linear response to SAs in the range of 5.0 × 10-7 to 1.1 × 10-4 mol L-1 of sulfonamide (R = 0.999), sulfamethazine (R = 0.990), sulfadiazine (R = 0.997), sulfamethoxazole (R = 0.996) and the limits of detection of 1.65 × 10-8, 3.19 × 10-8, 6.76 × 10-8 and 9.41 × 10-8 mol L-1, respectively. The recoveries were in the range of ca. 85-103% with relative standard deviation (RSD) < 5%. The sensor was tested by cyclic voltammetry with repeatability and stability of more than 90% of its original activity. The proposed method might offer feasibility and applicability of the sensor for further complex sulfonamides compounds.