Methoxy-activated indole-7-carbohydrazides; synthesis, antioxidant, and anticancer properties

Indole has been known as a key heterocyclic motif in the development of new structures for both chemical and biological properties. In this current study, a new range of indole-7-carbohydrazides has been successfully synthesized starting from the readily available 3-phenyl and 2,3-diphenyl 4,6-dimethoxyindoles. The structures of the novel compounds were confirmed by utilizing H-1 NMR, C-13 NMR, FT-IR, high-resolution mass spectrometry, and single crystal X- ray diffraction techniques. In addition, the indole-7-carbohydrazides showed promising antioxidant results in preliminary screens. Some of the new compounds generated from dimethoxy indoles were also screened for their anticancer activity against SH-SHY5Y (human neuroblastoma), AGS (human gastric adenocarcinoma), and MDA-MB-231 (human breast adenocarcinoma) cell lines. The results revealed that the compound 12 was the promising candidate, showing cytotoxic effects on both neuroblastoma, stomach, and breast cancer cells.