Indole and Indoline Scaffolds in Antimicrobials: Overview, Synthesis and Recent Advances in Antimicrobial Research

At present, a pandemic of antibiotic-resistant infectious diseases is an evergrowing threat. The need for new antibiotics and ways to combat antibiotic resistance is glaring. This review will focus on two different privileged scaffolds, the indole and the indoline, as useful nuclei for novel antibacterial compounds. The indole, a moiety found in numerous approved drugs for many disease states, has recently been studied for its usefulness as a scaffold for compounds that have activity against antibiotic-resistant bacteria, especially against methicillin-resistant Staphylococcus aureus (MRSA). The indoline is a scaffold with significantly less historical studies and FDA-approved drugs and it has attracted new interest in drug design and development. In recent years, indoline-containing compounds have been shown to have antibacterial activity as well as activity as a resistance- modifying agent (RMA), which act to improve the effectiveness of current antibiotic therapies that have known resistance.