3-hydroxy-3-(1H-indol-3-yl)-5-nitrooxindole and derivative.

The 3-hydroxy-3-(1H-indol-3-yl)-5-nitrooxindole (3) has been obtained in 88% yield from a reaction of 5-nitroisatin (1) and indole (2) using potassium carbonate as the catalyst. The catalytic reduction of 3 with hydrazine monohydrate and Pd/C catalyst produced 5-amino-3-hydroxy-3-(1H-indol-3-yl)oxindole (4) in 79% yield. The structure of 3 and 4 was justified by FT-IR, ¹H/¹³C NMR, and mass spectroscopies. The cytotoxicity assay of 3 and 4 on HepG2 cells indicated that compound 3 (IC₅₀ 0.39 mM) is more active than 4 (IC₅₀ 3.56 mM). The molecular docking studies of 3 dan 4 in the binding site of VEGFR2 kinase (PDB ID: 5EW3) showed that the binding energy of compound 3 (-9.1 kcal/mol) was better than that of compound 4 (-8.45 kcal/mol). According to their binding pose, both can be classified as type II kinase inhibitors against VEGFR2 kinase (PDB ID: 5EW3). [ABSTRACT FROM AUTHOR]