title: Siphonols A-E: novel nitric oxide inhibitors from Orthosiphon stamineus of Indonesia.
abstract: From the methanolic extract of Orthosiphon stamineus, four novel highly oxygenated isopimarane-type diterpenes named siphonols A-D (1-4) and a novel biogenetically interesting norisopimarane-type diterpene named siphonol E (5) were isolated. The new compounds 1-3 and 5 showed more potent inhibitory effects on the nitric oxide (NO) production in lipopolysaccharide (LPS)-activated macrophage-like J774.1 cells than a positive control N(G)-monomethyl-L-arginine (L-NMMA). Siphonols A-E (1-5) represent the first examples of isopimaranes oxygenated at C-20.
authors.affiliation: Institute of Natural Medicine, Toyama Medical and Pharmaceutical University, 2630-Sugitani, Japan.
authors.forename: Suresh
authors.initials: S
authors.lastname: Awale
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tezuka
authors.forename: Arjun H
authors.initials: AH
authors.lastname: Banskota
authors.forename: Shigetoshi
authors.initials: S
authors.lastname: Kadota
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000302:isolation & purification; D002460:Cell Line; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D007214:Indonesia; D020128:Inhibitory Concentration 50; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D015394:Molecular Structure; D009569:Nitric Oxide / Q000037:antagonists & inhibitors*; D019906:Nuclear Magnetic Resonance, Biomolecular; D031342:Orthosiphon / Q000737:chemistry*
chemical_list: D000893:Anti-Inflammatory Agents; D004224:Diterpenes; D008070:Lipopolysaccharides; C474660:siphonol A; C474659:siphonol E; D009569:Nitric Oxide