Phenolic Mannich Bases: Review on Synthetic Aspects and Biological Activity Profiles

Phenolic Mannich bases are important organic fragments in medicinal chemistry, as they combine the biological relevance of phenolic compounds with the structural flexibility of the Mannich base scaffold. They are synthesized by the straightforward condensation of phenols, nonenolizable aldehydes and amines in a one-pot synthesis. In recent years, researchers have paid significant attention to phenolic Mannich bases for their wide range of biological activities. Although several reviews have discussed structurally different Mannich bases and their biological activities, a review mainly focusing on phenolic Mannich bases and addressing their various biological activities, such as antimicrobial, anticancer, antimalarial, antioxidant and antiviral activities, has been limited. With this objective, we herein list various studies discussing these biological activities of phenolic Mannich bases along with structure-activity relationships. In addition, the most active compounds identified through in vitro studies are highlighted to understand the structural modifications required to design molecules with biological significance.