title: New protopine and benzyltetrahydroprotoberberine alkaloids from Aristolochia constricta and their activity on isolated guinea-pig ileum.
abstract: Five new protopine-type alkaloids, 3,5-di-O-methylconstrictosine (1), 5,6-dihydro-3,5-di-O-methylconstrictosine (2), 5,6-dihydroconstrictosine (3), constrictosine (4), 3-O-methylconstrictosine (5), and a novel 8-benzylberberine-type alkaloid, (-)-8 beta-(4'-hydroxybenzyl)-2,3-dimethoxyberbin-10-ol (6) were isolated from the aerial parts of Aristolochia constricta. Their structures were elucidated by physical and spectroscopic data. The results of our pharmacological experiments indicated that MeOH extract, its partially purified fraction VI and the protopine derivatives constrictosine 1-5, significantly reduced, in a dose dependent manner, the electrical, acetylcholine, and histamine contractions of the isolated guinea-pig ileum.
authors.affiliation: Dipartimento di Scienze Farmaceutiche, Facoltà, Università di Salerno, Penta di Fisciano (SA), Italy.
authors.forename: L
authors.initials: L
authors.lastname: Rastrelli
authors.forename: A
authors.initials: A
authors.lastname: Capasso
authors.forename: C
authors.initials: C
authors.lastname: Pizza
authors.forename: N
authors.initials: N
authors.lastname: De Tommasi
authors.forename: L
authors.initials: L
authors.lastname: Sorrentino
mesh_terms: D000109:Acetylcholine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000470:Alkaloids / Q000302:isolation & purification* / Q000494:pharmacology; D000818:Animals; D053119:Benzophenanthridines; D001600:Berberine Alkaloids / Q000302:isolation & purification* / Q000494:pharmacology; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology; D006633:Histamine Antagonists / Q000494:pharmacology; D007082:Ileum / Q000187:drug effects*; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009130:Muscle, Smooth / Q000187:drug effects*; D010276:Parasympatholytics / Q000302:isolation & purification* / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*
chemical_list: D000470:Alkaloids; D053119:Benzophenanthridines; D001600:Berberine Alkaloids; D006633:Histamine Antagonists; D010276:Parasympatholytics; D010936:Plant Extracts; D006632:Histamine; D000109:Acetylcholine; C009093:protopine