Alzheimer’s disease (AD) is one of the most common and complex neurodegenerative disorders worldwide. It mainly affects older adults and leads to permanent changes in the brain that gradually impair memory, thinking, behaviour, and everyday functioning. Despite more than a hundred years of scientific research, there is still no treatment that can stop or reverse the disease. For this reason, researchers continue to explore new approaches that target the underlying biological mechanisms of Alzheimer’s rather than its symptoms alone. Recent work by an international team of scientists from Poland and Spain highlights how combining different analytical techniques can help identify and better understand potential drug candidates.
One of the key features of Alzheimer’s disease is the accumulation of β-amyloid peptides in the brain, along with increased oxidative stress. Oxidative stress occurs when harmful reactive oxygen species are produced in excess, damaging neurons and other brain cells. A trace metal that plays a vital role in this process is copper. Under normal conditions, copper is essential for life, supporting enzymes involved in energy production, brain signalling, and protection against oxidative damage. However, when copper levels are not adequately regulated, the metal can become toxic. In Alzheimer’s disease, copper can bind to amyloid peptides, forming complexes that promote the production of free radicals and intensify oxidative stress, contributing to neuronal damage and disease progression.
To reduce this harmful activity, scientists are investigating molecules that can bind copper safely and control its reactivity in the brain. One promising compound is TDMQ20, a molecule designed to bind copper ions selectively. By acting as a chelator, TDMQ20 can potentially neutralise copper’s toxic effects while preserving its essential biological roles. The recent study focused on understanding how copper behaves when bound to TDMQ20, particularly during oxidation and reduction processes closely linked to oxidative stress. This is an important step in determining whether such a molecule could be safe and effective as a future drug.
The researchers used a combination of electrochemical techniques and spectroscopy to study the copper–TDMQ20 complex. These methods allowed them to observe how the complex responds to changes in electrical potential and how its structure and optical properties change during redox reactions. Their results showed that when copper is bound to TDMQ20, it becomes much less likely to participate in harmful redox reactions under normal physiological conditions. In particular, the reduction of the copper ion occurs only at very low potentials, which are not present in the human body. This suggests that the copper–TDMQ20 complex does not contribute to oxidative stress, making it a safer way to control copper activity.
The study also showed that the behaviour of the copper–TDMQ20 complex depends on pH, which is important because different parts of a cell have different acidity levels. Even when the complex is oxidised, copper remains bound to TDMQ20 rather than being released in a harmful form. These findings indicate that TDMQ20 forms a stable, predictable complex with copper under conditions similar to those in biological systems. Overall, this research suggests that TDMQ20 is a promising candidate for reducing copper-related oxidative stress in Alzheimer’s disease. Just as importantly, it demonstrates how combining electrochemistry, spectroscopy, and modelling can provide more precise and more reliable insight into how potential drug molecules behave in the body.
More information: Martin Perez-Estebanez et al, Spectroelectrochemical studies of TDMQ20: A potential drug against Alzheimer’s disease – part 2 – Cu-complexes, Bioelectrochemistry. DOI: 10.1016/j.bioelechem.2025.109115
Journal information: Bioelectrochemistry Provided by Institute of Physical Chemistry of the Polish Academy of Sciences
