(S)-3,9,10-Trimethoxy-6,8,13,13a-tetrahydro-5H-isoquinolino[3,2-a]isoquinolin-2-ol, commonly known as (-)-Isocorypalmine, is a tetrahydroprotoberberine alkaloid. It is a natural product isolated from various plant species, notably from the Corydalis genus. Its structure features a complex isoquinoline framework with methoxy and hydroxyl substituents, contributing to its biological activity. This compound is primarily recognized for its pharmacological properties related to the central nervous system. Research indicates that (-)-Isocorypalmine acts as a dopamine receptor ligand, specifically showing affinity for D1 and D5 receptor subtypes. This mechanism underpins its potential therapeutic interest in neurological and psychiatric disorders. It serves as a valuable chemical probe for studying dopaminergic pathways and as a lead compound in drug discovery efforts targeting these receptors. As a natural alkaloid, (-)-Isocorypalmine is also of significant interest in phytochemistry and traditional medicine research. Its isolation, structural elucidation, and biological evaluation contribute to the understanding of plant-derived bioactive molecules. It is typically handled as a research chemical for in vitro and in vivo studies to explore its full pharmacological profile and potential medicinal applications.