title: Rubescins A, B and C: new havanensin type limonoids from root bark of Trichilia rubescens (Meliaceae).
abstract: Three new limonoids, rubescins A-C (1-3), and three known compounds including, havanensin type limonoid TS3 (4), β-sitosterol, and stigmasterol were isolated from the root bark of Trichilia rubescens. Their structures were elucidated by means of extensive spectroscopic analyses, particularly one dimensional (1D)- and 2D-NMR techniques in conjunction with mass spectrometry. Rubescins A-C (1-3) and limonoid TS3 (4) were evaluated for their protective effects against oxidative stress induced in HC-04 cells by H2O2. Compound (1) showed strong inhibitory effects on lactase dehydrogenase (LDH) leakage, being as active (IC50 value of 0.0026 µM) as the positive control quercetin (IC50 value of 0.0030 µM).
authors.affiliation: Department of Organic Chemistry, University of Yaounde I.
authors.forename: Armelle
authors.initials: A
authors.lastname: Tsamo Tontsa
authors.forename: Pierre
authors.initials: P
authors.lastname: Mkounga
authors.forename: Fréderic Nico
authors.initials: FN
authors.lastname: Njayou
authors.forename: José
authors.initials: J
authors.lastname: Manautou
authors.forename: Marat
authors.initials: M
authors.lastname: Kirk
authors.forename: Philip Gregory
authors.initials: PG
authors.lastname: Hultin
authors.forename: Augustin Ephrem
authors.initials: AE
authors.lastname: Nkengfack
mesh_terms: D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity; D036701:Limonins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D029582:Meliaceae / Q000737:chemistry* / Q000378:metabolism; D008968:Molecular Conformation; D018384:Oxidative Stress / Q000187:drug effects; D024301:Plant Bark / Q000737:chemistry / Q000378:metabolism; D018517:Plant Roots / Q000737:chemistry / Q000378:metabolism; D020011:Protective Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D036701:Limonins; D020011:Protective Agents; C479320:havanensin; C000588776:rubescin A; D006861:Hydrogen Peroxide