title: Mexican propolis flavonoids affect photosynthesis and seedling growth.
abstract: As a continuous effort to find new natural products with potential herbicide activity, flavonoids acacetin (1), chrysin (2) and 4',7-dimethylnarangenin (3) were isolated from a propolis sample collected in the rural area of Mexico City and their effects on the photosynthesis light reactions and on the growth of Lolium perenne, Echinochloa crus-galli and Physalis ixocarpa seedlings were investigated. Acacetin (1) acted as an uncoupler by enhancing the electron transport under basal and phosphorylating conditions and the Mg(2+)-ATPase. Chrysin (2) at low concentrations behaved as an uncoupler and at concentrations up to 100 μM its behavior was as a Hill reaction inhibitor. Finally, 4',7-dimethylnarangenin (3) in a concentration-dependent manner behaved as a Hill reaction inhibitor. Flavonoids 2 and 3 inhibited the uncoupled photosystem II reaction measured from water to 2,5-dichloro-1,4-benzoquinone (DCBQ), and they did not inhibit the uncoupled partial reactions measured from water to sodium silicomolybdate (SiMo) and from diphenylcarbazide (DPC) to diclorophenol indophenol (DCPIP). These results indicated that chrysin and 4',7-dimethylnarangenin inhibited the acceptor side of PS II. The results were corroborated with fluorescence of chlorophyll a measurements. Flavonoids also showed activity on the growth of seedlings of Lolium perenne and Echinochloa crus-galli.
authors: Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, 04510 México, DF, Mexico.
authors: Beatriz
authors: B
authors: King-Díaz
authors: Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, 04510 México, DF, Mexico.
authors: Jessica
authors: J
authors: Granados-Pineda
authors: Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario, Cerro de las Campanas, Querétaro 76010, Mexico.
authors: Mustapha
authors: M
authors: Bah
authors: Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, 04510 México, DF, Mexico.
authors: J Fausto
authors: JF
authors: Rivero-Cruz
authors: Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, 04510 México, DF, Mexico. Electronic address: blas@unam.mx.
authors: Blas
authors: B
authors: Lotina-Hennsen
mesh_terms: D001120:Arginine / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical / Q000379:methods; D031747:Echinochloa / Q000187:drug effects / Q000254:growth & development; D047309:Flavones / Q000737:chemistry / Q000494:pharmacology; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D006540:Herbicides / Q000737:chemistry / Q000494:pharmacology; D008129:Lolium / Q000187:drug effects / Q000254:growth & development; D009682:Magnetic Resonance Spectroscopy; D008800:Mexico; D010788:Photosynthesis / Q000187:drug effects*; D045332:Photosystem II Protein Complex / Q000037:antagonists & inhibitors / Q000378:metabolism; D032321:Physalis / Q000187:drug effects / Q000254:growth & development; D011429:Propolis / Q000737:chemistry*; D036226:Seedlings / Q000187:drug effects* / Q000254:growth & development; D018724:Spinacia oleracea / Q000187:drug effects
chemical_list: C000614536:4',7-dimethylnarangenin; D047309:Flavones; D005419:Flavonoids; D006540:Herbicides; D045332:Photosystem II Protein Complex; C043561:chrysin; D011429:Propolis; D001120:Arginine; C023717:acacetin
keywords: 4′,7-dimethylnarangenin; Acacetin; Chrysin; Photosynthesis; Propolis; Seedling growth