L-(R,S)-Tetrahydropalmatine (Rotundine) is extracted from Corydalis yanhusuo W. T. Wang.

Tetrahydropalmatine hydrochloride (Gindarine hydrochloride) is an isoquinoline alkaloid found in several different plant species, mainly in the Corydalis genus (Yan Hu Suo). It is a potent muscle relaxant.

Tetrahydropalmatine (DL-Tetrahydropalmatine) is an active component isolated from corydalis, suppressing amygdaloid release of dopamine to inhibit an epileptic attack in rats.

D-Tetrahydropalmatine is a organic cation transporter 1 (OCT1) inhibitor, it can obviously inhibit the uptake of monocrotaline (MCT) in MDCK-hOCT1 cells and isolate rat primary hepatocytes, and attenuate the viability reduction and LDH release of the prim

Rotundine (Gindarine) (L-tetrahydropalmatine, L-THP) is a selective dopamine D1 receptor antagonist with IC50 of 166 nM.