title: Taraxerol 4-Methoxybenzoate, an in vitro Inhibitor of Photosynthesis Isolated from Pavonia multiflora A. St-Hil. (Malvaceae).
abstract: A phytochemical study of Pavonia multiflora A. St-Hil. (Malvaceae) led to the isolation through chromatographic techniques of 10 secondary metabolites: vanillic acid (1), ferulic acid (2), p-hydroxybenzoic acid (3), p-coumaric acid (4), loliolide (5), vomifoliol (6), 4,5-dihydroblumenol A (7), 3-oxo-α-ionol (9), blumenol C (10), and taraxerol 4-methoxybenzoate (8), the latter being a novel metabolite. Their structures were identified by (1) H- and (13) C-NMR, using one- and two-dimensional techniques, and X-ray crystallography. In this work, we report the effect of compounds 5 and 8 on several photosynthetic activities in an attempt to search for new compounds as potential herbicide agents that affect photosynthesis. Both compounds inhibited the electron flow from H2 O to methyl viologen; therefore, they act as Hill reaction inhibitors. Using polarographic techniques and studies of the fluorescence of chlorophyll a, the interaction sites of these compounds were located at photosystem II.
authors.affiliation: Department of Chemistry, Federal University of Espírito Santo, Vitória, ES, 29060-700, Brazil.
authors.forename: Leandra Gobira
authors.initials: LG
authors.lastname: Lopes
authors.affiliation: Department of Chemistry, Federal University of Espírito Santo, Vitória, ES, 29060-700, Brazil.
authors.forename: Gabriela Lopes
authors.initials: GL
authors.lastname: Tavares
authors.affiliation: Department of Biology, Federal University of Espírito Santo, Vitória, ES, 29060-700, Brazil.
authors.forename: Luciana Dias
authors.initials: LD
authors.lastname: Thomaz
authors.affiliation: Physics Institute, Federal University of Goiás, Goiânia, GO, 74000-970, Brazil.
authors.forename: José Ricardo
authors.initials: JR
authors.lastname: Sabino
authors.affiliation: Department of Natural Sciences, Federal University of São João Del Rei, São João Del Rei, MG, 36307-066, Brazil.
authors.forename: Keyller Bastos
authors.initials: KB
authors.lastname: Borges
authors.affiliation: Department of Chemistry, Federal University of São Carlos, São Carlos, SP, 13565-905, Brazil.
authors.forename: Paulo Cezar
authors.initials: PC
authors.lastname: Vieira
authors.affiliation: Institute of Environmental Sciences, Chemical and Pharmaceutical, Diadema, SP, 09972-270, Brazil.
authors.forename: Thiago André Moura
authors.initials: TAM
authors.lastname: Veiga
authors.affiliation: Department of Chemistry, Federal University of Espírito Santo, Vitória, ES, 29060-700, Brazil.
authors.forename: Warley
authors.initials: W
authors.lastname: de Souza Borges
mesh_terms: D066298:In Vitro Techniques; D019660:Malvaceae / Q000737:chemistry*; D009828:Oleanolic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D010788:Photosynthesis / Q000187:drug effects*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D045322:Photosynthetic Reaction Center Complex Proteins; C000612652:taraxerol 4-methoxybenzoate; D009828:Oleanolic Acid
keywords: Norisoprenoids; Pavonia multiflora; Phenolic compounds; Photosynthetic inhibitor; Taraxerol 4-methoxybenzoate