title: Inhibition of Na+,K+-ATPase activity by (-)-ent-Kaur-16-en-19-oic acid and its derivatives.
abstract: The diterpene, (-)- ent-kaur-16-en-19-oic acid, from Croton oblongifolius was identified as an Na +,K +-ATPase inhibitor. This compound exhibits an IC 50 of 2.2 x 10( -5 )M against crude enzyme Na +,K +-ATPase from rat brain. The semi-synthetic derivatives, (-)-methyl kaur-16-en-19-oate, (-)-kaur-16-en-19-ol, (-)-16beta,17-epoxykauran-19-oic acid and (-)-17-hydroxykaur-15-en-19-oic acid were also tested and their IC 50 were 5.5 x 10 (-4), 5.0 x 10( -4), 4.8 x 10( -4) and 6.0 x 10 (-4) M, respectively.
authors.affiliation: Research Centre for Bioorganic Chemistry, Department of Chemistry, Faculty of Science, Chulalongkorn University, Pathumwan, Bangkok, Thailand.
authors.forename: Nattaya
authors.initials: N
authors.lastname: Ngamrojnavanich
authors.forename: Supaporn
authors.initials: S
authors.lastname: Sirimongkon
authors.forename: Sophon
authors.initials: S
authors.lastname: Roengsumran
authors.forename: Amorn
authors.initials: A
authors.lastname: Petsom
authors.forename: Hishashi
authors.initials: H
authors.lastname: Kamimura
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology; D029802:Croton; D004224:Diterpenes / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D020128:Inhibitory Concentration 50; D008517:Phytotherapy; D024301:Plant Bark; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D018547:Plant Stems; D051381:Rats; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*
chemical_list: D004224:Diterpenes; D004791:Enzyme Inhibitors; D010936:Plant Extracts; C014341:argyrophilic acid; D000254:Sodium-Potassium-Exchanging ATPase