Purine alkaloids and other nucleophilic small molecules

Purine alkaloids and other nucleophilic small molecules do not constitute a single therapeutic target but rather represent a chemical class of compounds, primarily methylxanthines, that interact with various biological targets. The most prominent members of this group include caffeine, theophylline, and theobromine, which are naturally occurring substances found in coffee, tea, and cocoa. Biologically, these molecules function as competitive antagonists of adenosine receptors (A1, A2A, A2B, and A3) and as non-selective inhibitors of phosphodiesterase enzymes, which results in the accumulation of cyclic AMP. These actions lead to physiological effects such as central nervous system stimulation, bronchodilation, and diuresis. In clinical practice, they are utilized for the treatment of respiratory conditions like asthma and COPD, as well as for neonatal apnea. Because this entry describes a class of ligands rather than a specific protein or receptor, it is classified as an incorrect target designation.

Other names

MethylxanthinesXanthine alkaloids

These molecules typically act as non-selective adenosine receptor antagonists and non-selective phosphodiesterase inhibitors, leading to increased intracellular cAMP levels and bronchodilation.