title: Urease inhibitors from Hypericum oblongifolium WALL.
abstract: The bioassay-guided fractionation of H. oblongifolium has led to the isolation of potent urease inhibitors 1-3. The structures were elucidated by NMR and mass spectroscopic techniques. Compound 2 showed a potent enzyme inhibition activity (IC(50) 20.96 +/- 0.93), which is comparatively higher than that for the standard thiourea (IC(50) 21.01 +/- 0.51 microM). Compounds 1 and 3 also showed a significant activity, with IC(50) 37.95 +/- 1.93 and 138.43 +/- 1.23 microM, respectively. The sub crude fractions (F1, F2, F3, and F4) were tested in vitro for their urease inhibition activity. Fractions F2 and F4 showed significant activity with IC(50) 140.37 +/- 1.93 and 167.43 +/- 3.03 microM, respectively.
authors.affiliation: Institute of Chemical Sciences, University of Peshawar, Peshawar, Pakistan.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Arfan
authors.forename: Mumtaz
authors.initials: M
authors.lastname: Ali
authors.forename: Habib
authors.initials: H
authors.lastname: Ahmad
authors.forename: Itrat
authors.initials: I
authors.lastname: Anis
authors.forename: Ajmal
authors.initials: A
authors.lastname: Khan
authors.forename: M Iqbal
authors.initials: MI
authors.lastname: Choudhary
authors.forename: Muhammad Raza
authors.initials: MR
authors.lastname: Shah
mesh_terms: D057075:Enzyme Assays; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D020902:Hypericum / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D018547:Plant Stems / Q000737:chemistry; D013890:Thiourea / Q000737:chemistry; D014510:Urease / Q000037:antagonists & inhibitors* / Q000737:chemistry
chemical_list: D004791:Enzyme Inhibitors; D010936:Plant Extracts; D014510:Urease; D013890:Thiourea