Quinolizidine-Type Alkaloids: Chemodiversity, Occurrence, and Bioactivity

Quinolizidine alkaloids(QAs) are nitrogen-containing compoundsproduced naturally as specialized metabolites distributed in plantsand animals (e.g., frogs, sponges). The present review compiles theavailable information on the chemical diversity and biological activityof QAs reported during the last three decades. So far, 397 QAs havebeen isolated, gathering 20 different representative classes, includingthe most common such as matrine (13.6%), lupanine (9.8%), anagyrine(4.0%), sparteine (5.3%), cytisine (6.5%), tetrahydrocytisine (4.3%),lupinine (12.1%), macrocyclic bisquinolizidine (9.3%), biphenylquinolizidinelactone (7.1%), dimeric (7.1%), and other less known QAs (20.9%),which include several structural patterns of QAs. A detailed surveyof the reported information about the bioactivities of these compoundsindicated their potential as cytotoxic, antiviral, antimicrobial,insecticidal, anti-inflammatory, antimalarial, and antiacetylcholinesterasecompounds, involving favorable putative drug-likeness scores. In thisregard, research progress on the structural and biological/pharmacologicaldiversity of QAs requires further studies oriented on expanding thechemical space to find bioactive scaffolds based on QAs for pharmacologicaland agrochemical applications.