title: Antibacterial activities of Ligaria cuneifolia and Jodina rhombifolia leaf extracts against phytopathogenic and clinical bacteria.
abstract: Six plant extracts prepared from Ligaria cuneifolia and Jodina rhombifolia were screened for their potential antimicrobial activities against phytopathogens and clinically standard reference bacterial strains. Bioautography and broth microdilution methods were used to study samples antibacterial activities against 7 bacterial strains. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of samples were attained. An antibacterial activity guided isolation and identification of active compounds was carried out for L. cuneifolia methanolic extract (LCME). Both methanolic and aqueous extracts from L. cuneifolia showed inhibitory activities against phytopathogenic bacteria, with MICs ranging from 2.5 to 156 μg mL(-1) for LCME and 5 mg mL(-1) for the aqueous extract. None of the three J. rhombifolia extracts showed significant antibacterial activities against phytopathogenic strains (MIC > 5 mg mL(-1)), except for the aqueous extracts against Pseudomonas syringae (MIC = 312 μg mL(-1)). Only LCME showed bactericidal activities against phytopathogenic strains (MBCs = 78 μg mL(-1)). The LCME exhibited significant inhibitory activity against reference clinical strains: Escherichia coli (MIC = 156 μg mL(-1)) and Staphylococcus aureus (MIC = 78 μg mL(-1), MBC = 312 μg mL(-1)). LCME active compounds were identified as flavonol mono and diglycosides, and gallic acid. The antibacterial activity of purified compounds was also evaluated. A synergistic effect against S. aureus was found between gallic acid and a quercetin glycoside. Hence, anti-phytopathogenic bacteria potential compounds isolated from L. cuneifolia could be used as an effective source against bacterial diseases in plants.
authors.affiliation: Laboratorio de Biología de Agentes Bioactivos y Fitopatógenos (LABIFITO), Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 471, T4000INI San Miguel de Tucumán, Tucumán, Argentina; Universidad Nacional de Tucumán, Ayacucho 491, T4000INI San Miguel de Tucumán, Tucumán, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Rivadavia 1917, C1033AAJ Ciudad Autónoma de Buenos Aires, Argentina. Electronic address: jrsrody@yahoo.com.
authors.forename: José R
authors.initials: JR
authors.lastname: Soberón
authors.affiliation: Laboratorio de Biología de Agentes Bioactivos y Fitopatógenos (LABIFITO), Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 471, T4000INI San Miguel de Tucumán, Tucumán, Argentina; Universidad Nacional de Tucumán, Ayacucho 491, T4000INI San Miguel de Tucumán, Tucumán, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Rivadavia 1917, C1033AAJ Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Melina A
authors.initials: MA
authors.lastname: Sgariglia
authors.affiliation: Universidad Nacional de Tucumán, Ayacucho 491, T4000INI San Miguel de Tucumán, Tucumán, Argentina.
authors.forename: María R
authors.initials: MR
authors.lastname: Dip Maderuelo
authors.affiliation: Laboratorio de Biología de Agentes Bioactivos y Fitopatógenos (LABIFITO), Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 471, T4000INI San Miguel de Tucumán, Tucumán, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Rivadavia 1917, C1033AAJ Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: María L
authors.initials: ML
authors.lastname: Andina
authors.affiliation: Laboratorio de Biología de Agentes Bioactivos y Fitopatógenos (LABIFITO), Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 471, T4000INI San Miguel de Tucumán, Tucumán, Argentina; Universidad Nacional de Tucumán, Ayacucho 491, T4000INI San Miguel de Tucumán, Tucumán, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Rivadavia 1917, C1033AAJ Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Diego A
authors.initials: DA
authors.lastname: Sampietro
authors.affiliation: Laboratorio de Biología de Agentes Bioactivos y Fitopatógenos (LABIFITO), Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 471, T4000INI San Miguel de Tucumán, Tucumán, Argentina; Universidad Nacional de Tucumán, Ayacucho 491, T4000INI San Miguel de Tucumán, Tucumán, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Rivadavia 1917, C1033AAJ Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Marta A
authors.initials: MA
authors.lastname: Vattuone
mesh_terms: D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects* / Q000472:pathogenicity*; D004926:Escherichia coli / Q000187:drug effects; D044948:Flavonols / Q000494:pharmacology; D005707:Gallic Acid / Q000494:pharmacology; D006027:Glycosides / Q000494:pharmacology; D028183:Loranthaceae / Q000737:chemistry; D019684:Magnoliopsida / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D010935:Plant Diseases / Q000382:microbiology*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry*; D044224:Pseudomonas syringae / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D044948:Flavonols; D006027:Glycosides; D010936:Plant Extracts; D005707:Gallic Acid
keywords: Gallic acid; Isoquercitrin; Jodina rhombifolia; Ligaria cuneifolia; Phenolics; Phytopathogenic bacteria; Synergic effect