title: Isolation and identification of tetrahydrocolumbamine as a dopamine receptor ligand from Polygala tenuifolia Willd.
abstract: The isolation and purification of a dopamine receptor ligand, tetrahydrocolumbamine from Polygala tenuifolia Willd is described. Tetrahydrocolumbamine was shown to inhibit the binding of [3H]-SCH23390 and [3H]-spiroperidol to rat striatum membranes in vitro with IC50 values of 0.75 +/- 0.08 mumol.L-1 and 0.92 +/- 0.10 mumol.L-1, respectively. The compound inhibited the binding of [3H]-prazosin (IC50 value of 46 mumol.L-1), while it did not change the binding of the ligands, [3H]-QNB and [3H]-muscimol to rat cortex in vitro. Scatchard plot analysis showed a mixture of competitive and non-competitive inhibition by the compound on both [3H]-SCH23390 and [3H]-spiroperidol binding to membranes from rat striatum.
authors.affiliation: Department of Biochemistry, St. Hans Hospital, Roskilde, Denmark.
authors.forename: X L
authors.initials: XL
authors.lastname: Shen
authors.forename: M R
authors.initials: MR
authors.lastname: Witt
authors.forename: K
authors.initials: K
authors.lastname: Dekermendjian
authors.forename: M
authors.initials: M
authors.lastname: Nielsen
mesh_terms: D000818:Animals; D001552:Benzazepines / Q000378:metabolism*; D001600:Berberine Alkaloids / Q000302:isolation & purification / Q000494:pharmacology*; D001667:Binding, Competitive; D002462:Cell Membrane / Q000378:metabolism; D003342:Corpus Striatum / Q000378:metabolism*; D004365:Drugs, Chinese Herbal / Q000737:chemistry; D008297:Male; D011224:Prazosin / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011954:Receptors, Dopamine; D013134:Spiperone / Q000378:metabolism*
chemical_list: D001552:Benzazepines; D001600:Berberine Alkaloids; D004365:Drugs, Chinese Herbal; D011954:Receptors, Dopamine; D013134:Spiperone; C092892:tetrahydrocolumbamine; D011224:Prazosin