Synthesis and Biological Evaluation of Aminonaphthols Incorporated Indole Derivatives

An efficient one pot condensation of naphthols (1), 2,5-disubstituted indole-3-carboxaldehydes (2), and secondary amines (3) has been achieved using dichloromethane as a solvent, stirring at room temperature. Some of the new [(disubstituted amino)(5-substituted 2-phenyl-1H-indol-3-yl)methyl]naphthalene-ols (4) derivatives were prepared in good yields. The significant features of this method are simple work-up procedure, inexpensive nontoxic solvent, shorter reaction times, and excellent product yields. The structures of newly synthesized compounds (4a–r) are confirmed by their elemental analysis, FTIR, 1H and 13C NMR, and mass spectral data. These compounds were screened for their in vitro antioxidant, antimicrobial, antitubercular, and anticancer activities. Among the synthesized compounds (4a–r), the compound 4e exhibited highest activity for radical scavenging and ferric ions reducing antioxidant power activities; compounds 4b, 4h, and 4k showed good metal chelating activity. Compounds 4n and 4q showed excellent antimicrobial activities with MIC value 08？μg/mL against tested strains. Compounds 4h, 4k, 4n, and 4q exhibited promising antitubercular activity with MIC value 12.5？μg/mL. Compounds 4k and 4q exhibited 100% cell lysis at concentration 10？μg/mL against MDA-MB-231 (human adenocarcinoma mammary gland) cell lines. 1. Introduction The search and evaluation of chemical compounds and their derivatives with a specific pharmacological activity are a demanding task in the drug discovery process. During last few years, the synthesis of aminoalkylnaphthols has received special attention from the scientific community because of their significant biological [1] and catalytic [2] properties. Multicomponent reactions (MCRs) have emerged as an efficient and powerful tool in modern organic chemistry for the synthesis of biologically potent molecules from readily available substrates without isolation of intermediates in minimal time with maximum selectivity. MCRs have proved to be very powerful and efficient bond-forming tool in synthetic chemistry; the reactions are flexible, of high atom economy, and of high purity with excellent yields [3]. Oxidative stress is a well-known mechanism that is responsible for the development of vascular damage. Oxidative stress results from an imbalance between (i) an overproduction of reactive oxygen species (ROS) by the different cellular sources such as the mitochondrial respiratory chain, nicotinamide adenine dinucleotide phosphate hydride oxidases (NADPHOXs or NOX), xanthine oxidase, lipoxygenases, cytochrome-P450, and