Recent Advances in Synthetic Isoquinoline-Based Derivatives in Drug Design

Compounds based on an isoquinoline scaffold (benzo[c]pyridine) display a broad spectrum of biological activities. In recent years, studies have focused mainly on their anticancer properties. Their antiproliferative effects are associated with diverse mechanisms that include targeting PI3K/Akt/mTOR signaling pathways and reactive oxygen species or inducing apoptosis and cell cycle arrest. Furthermore, isoquinolines may inhibit microtubule polymerization, topoisomerase, or tumor multidrug resistance. Recent studies have also shown that these compounds may act as effective antimicrobial, antifungal, antiviral, and antiprotozoal agents. Moreover, it has also been demonstrated that isoquinoline derivatives exhibit potent anti-Alzheimer effects, alleviating central nervous system functions. Additionally, they possess anti-inflammatory and antidiabetic properties. Due to the presence of donor nitrogen, the isoquinoline core constitutes an appropriate ligand that may be employed for the development of metal complexes with improved pharmacological properties. A number of chelates containing copper, iridium, or platinum were found to exhibit prominent biological activity, which places them in a leading position for the development of effective medications. This review summarizes the recent development of synthetic isoquinoline-based compounds with proven pharmacological properties in the period of 2020–2025. Also, other biomedical applications for synthetic isoquinoline derivatives are provided.