Indole Derivatives in Medicinal Applications

Indole derivatives represent a cornerstone of medicinal chemistry, combining a bicyclic aromatic core with diverse substitution patterns to yield compounds of remarkable biological significance. The indole nucleus serves as a privileged scaffold, fostering high affinity interactions with protein targets, including kinases, receptors and nucleic acid enzymes. Modifications at the C-3 position, N-1 nitrogen and other ring positions have generated libraries of molecules exhibiting anticancer, antimicrobial, antiviral, antioxidant and neuroprotective activities. Synthetic advances, such as one-pot multicomponent assembly, have streamlined access to complex indole architectures, accelerating lead optimisation and facilitating structure–activity exploration. Natural and bisindole alkaloids continue to inspire novel designs, while computational docking and ADME profiling guide the selection of drug-like candidates. Collectively, these efforts underscore the global relevance of indole chemistry for confronting emergent and chronic diseases.

Research from Nature Portfolio

Recent studies have introduced a modular multicomponent reaction enabling the rapid, single-step assembly of tetrahydrocarboline-type indole alkaloids from simple indole, formaldehyde and amine hydrochloride building blocks. This protocol tolerates a wide array of functional groups, forging both γ- and β-tetrahydrocarbolines through an unusual C(sp3)–C(sp3) alkylamination cascade. Mechanistic investigations, including deuterium labelling, revealed key intermediates and have expanded the accessible indole alkaloid library for drug discovery. In parallel, a series of C-3 substituted indoles was synthesised and evaluated for antioxidant and cytoprotective efficacy. The most active derivatives combined an unsubstituted indole nitrogen with electron-rich substituents to stabilise radicals, offering potent protection of human erythrocytes against oxidative haemolysis. Structure–activity correlations and membrane interaction studies have informed further optimisation of indole-based antioxidants.

Indole Derivatives in Medicinal Applications publication trend

The graph below shows the total number of articles in indole derivatives in medicinal applications across all publications each year (not limited to Nature Index journals).

Technical terms

Indole nucleus: A bicyclic aromatic structure composed of a six-membered benzene ring fused to a five-membered pyrrole ring, serving as a core scaffold in many bioactive molecules.

Pharmacophore: The ensemble of steric and electronic features necessary to ensure optimal interactions with a specific biological target and to trigger (or block) its biological response.

Multicomponent reaction: A synthetic process in which three or more reactants combine in a single operation to form a product incorporating substantial fragments of each starting material.

Cytoprotective activity: The ability of a compound to safeguard cells from chemical or physical insults, often assessed by preventing oxidative damage or membrane disruption.

Hemolytic activity: The capacity of a substance to cause rupture of red blood cells, releasing haemoglobin into the surrounding medium, an important parameter for safety evaluation.

References

1. Modular assembly of indole alkaloids enabled by multicomponent reaction. Nature Communications (2023).
2. Synthesis, antioxidant and cytoprotective activity evaluation of C-3 substituted indole derivatives. Scientific Reports (2021).
3. Novel C3-Methylene-Bridged Indole Derivatives with and without Substituents at N1: The Influence of Substituents on Their Hemolytic, Cytoprotective, and Antimicrobial Activity. International Journal of Molecular Sciences (2024).
4. Indole-Acrylonitrile Derivatives as Potential Antitumor and Antimicrobial Agents—Synthesis, In Vitro and In Silico Studies. Pharmaceuticals (2023).
5. Bisindole Compounds—Synthesis and Medicinal Properties. Antibiotics (2024).