a D₁/D₂ dopaminergic receptors antagonist with sedative tranquillizing action; as a Tetrahydropalmatine analog, probably blocks voltage dependent calcium channels.

Berberis diisoquinoline alkaloid C₂₀H₂₁NO₄ synthetic

• Molecular Weight : 339.38 Da.
  
  
• Melting Point : 168-169°C.
  
  
• Solubility in : chloroform; not well in ethanol and methanol.
  
  
• Purity min. : 95 % (TLC, mass-spectrometry).
  
  
• Biological Activity : Tetrahydroberberine presents a sedative/tranquillizing effect, probably due to its blocking action on D₁/D₂ receptors in brain. In contrast with the other non specific D₁/D₂ receptors blockers, Tetrahydroberberine does not cause catalepsy. (Niwa et al., 1991); Tetrahydroberberine is probably a calcium antagonist.
  
  
• Toxicity (LD₅₀) : mice (orally): 935 mg/kg (880-990).
  mice (s.c.): 750 mg/kg (685-819).
  mice (i.v.): 95 mg/kg (80-112).
  
  
• Storage recommendations : Store at +4°C, in dark place.
  
  
• CAS Reg. No. : 522-97-4
  
  
• Merck Index 11th Ed. : 1744
  
  
• Bibliography :
  
  1. Niwa et al., "Dopaminergic unique affinity of tetrahydroberberine and l-tetrahydroberberine-d-camphor sulfonate". Parmacology (1991). 43:329-336
  2. Yamahara "Behavioral pharmacology of berberine-type alkaloids. II. Central depressant effect of tetrahydroberberine (THB) and its related compounds." Folia Pharmacol. Jap. (1976). 72:909-927