Exploring Macrocyclic Chemical Space: Strategies and Technologies for Drug Discovery

Macrocycles have emerged as significant therapeutic candidates in drug discovery due to their unique capacity to target complex and traditionally inaccessible biological interfaces. Their structurally constrained three-dimensional configurations facilitate high-affinity interactions with challenging targets, notably protein-protein interfaces. However, despite their potential, the synthesis and optimization of macrocyclic compounds present considerable challenges related to structural complexity, synthetic accessibility, and the attainment of favorable drug-like properties, particularly cell permeability and oral bioavailability. Recent advancements in synthetic methodologies have expanded the chemical space accessible to macrocycles, enabling the creation of structurally diverse and pharmacologically active compounds. Concurrent developments in computational strategies have further enhanced macrocycle design, providing valuable insights into structural optimization and predicting molecular properties essential for therapeutic efficacy. Additionally, a deeper understanding of macrocycles' conformational adaptability, especially their ability to internally shield polar functionalities to improve membrane permeability, has significantly informed their rational design. This review discusses recent innovations in synthetic and computational methodologies that have advanced macrocycle drug discovery over the past five years. It emphasizes the importance of integrating these strategies to overcome existing challenges, illustrating how their synergy expands the therapeutic potential and chemical diversity of macrocycles. Selected case studies underscore the practical impact of these integrated approaches, highlighting promising therapeutic applications across diverse biomedical targets.