A Comprehensive Review of Tropane Alkaloids: Atropine from Origin to Biological Activity

Tropane alkaloids (TAs) are a distinct class of secondary metabolites primarily found in the Solanaceae family, characterized by a unique bicyclic tropane ring. Among them, atropine is one of the most extensively studied and clinically significant compounds. This comprehensive review explores atropine's origin, chemical classification, biosynthesis, extraction, identification, and pharmacological properties. Derived biosynthetically from ornithine and phenylalanine, atropine is synthesized via a complex pathway that includes the intermediates littorine and hyoscyamine. Though not naturally present in free form, atropine is obtained through the racemization of hyoscyamine during extraction from plants like Atropa belladonna and Datura species. Chemically, atropine functions as a potent anticholinergic agent, acting primarily on muscarinic receptors, and demonstrates significant biological activities. Clinically, atropine is used to manage bradycardia, myopia progression, smooth muscle spasms, and gastric disorders, showing high efficacy with manageable side effects under medical supervision. Advances in structural elucidation, biosynthetic pathway analysis, and pharmacological profiling continue to support atropine’s relevance in modern medicine. However, due to its strong pharmacological effects, appropriate dosing and regulatory oversight remain critical. Overall, atropine exemplifies the therapeutic potential and complexity of natural product-based drug discovery.