title: Antibacterial Activity, Antioxidant Effect and Chemical Composition of Propolis from the Región del Maule, Central Chile.
abstract: Propolis is commercialized in Chile as an antimicrobial agent. It is obtained mainly from central and southern Chile, but is used for the same purposes regardless of its origin. To compare the antimicrobial effect, the total phenolic (TP), the total flavonoid (TF) content and the phenolic composition, 19 samples were collected in the main production centers in the Región del Maule, Chile. Samples were extracted with MeOH and assessed for antimicrobial activity against Gram (+) and Gram (-) bacteria. TP and TF content, antioxidant activity by the DPPH, FRAP and TEAC methods were also determined. Sample composition was assessed by HPLD-DAD-ESI-MS/MS. Differential compounds in the samples were isolated and characterized. The antimicrobial effect of the samples showed MICs ranging from 31.5 to > 1000 µg/mL. Propolis from the central valley was more effective as antibacterial than those from the coastal area or Andean slopes. The samples considered of interest (MIC ≤ 62.5 µg/mL) showed effect on Escherichia coli, Pseudomonas sp., Yersinia enterocolitica and Salmonella enteritidis. Two new diarylheptanoids, a diterpene, the flavonoids pinocembrin and chrysin were isolated and elucidated by spectroscopic and spectrometric means. Some 29 compounds were dereplicated by HPLC-MS and tentatively identified, including nine flavones/flavonol derivatives, one flavanone, eight dihydroflavonols and nine phenyl-propanoids. Propolis from the Región del Maule showed large variation in antimicrobial effect, antioxidant activity and composition. So far the presence of diarylheptanoids in samples from the coastal area of central Chile can be considered as a marker of a new type of propolis.
authors.affiliation: Laboratorio de Química de Productos Naturales, Instituto de Química de Recursos Naturales, Universidad de Talca, Casilla 747, Talca 3460000, Chile. vica17_a@hotmail.com.|Facultad de Ciencias de la Salud, Programa de Magister en Ciencias Biomédicas, Universidad de Talca, Talca 3460000, Chile. vica17_a@hotmail.com.
authors.forename: Nélida
authors.initials: N
authors.lastname: Nina
authors.affiliation: Laboratorio de Química de Productos Naturales, Instituto de Química de Recursos Naturales, Universidad de Talca, Casilla 747, Talca 3460000, Chile. elquispe@unap.cl.|Facultad de Ciencias de la Salud, Universidad Arturo Prat, Casilla 121, Iquique 1110939, Chile. elquispe@unap.cl.
authors.forename: Cristina
authors.initials: C
authors.lastname: Quispe
authors.affiliation: Laboratorio de Química de Productos Naturales, Instituto de Química de Recursos Naturales, Universidad de Talca, Casilla 747, Talca 3460000, Chile. fjimenez@utalca.cl.
authors.forename: Felipe
authors.initials: F
authors.lastname: Jiménez-Aspee
authors.affiliation: Laboratorio de Cultivo Celular, Facultad de Ciencias de la Salud, Universidad de Talca, Casilla 747, Talca 3460000, Chile. ctheodul@utalca.cl.
authors.forename: Cristina
authors.initials: C
authors.lastname: Theoduloz
authors.affiliation: Instituto de Biotecnología, Facultad de Ingeniería, Universidad Nacional de San Juan, Av. Libertador General San Martin 1109 (oeste), San Juan 5400, Argentina. gferesin@unsj.edu.ar.
authors.forename: Gabriela Egly
authors.initials: GE
authors.lastname: Feresín
authors.affiliation: Instituto de Biotecnología, Facultad de Ingeniería, Universidad Nacional de San Juan, Av. Libertador General San Martin 1109 (oeste), San Juan 5400, Argentina. blima.unsj@gmail.com.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Lima
authors.affiliation: Facultad de Ciencias de la Salud, Programa de Magister en Ciencias Biomédicas, Universidad de Talca, Talca 3460000, Chile. eleivam@utalca.cl.
authors.forename: Elba
authors.initials: E
authors.lastname: Leiva
authors.affiliation: Laboratorio de Química de Productos Naturales, Instituto de Química de Recursos Naturales, Universidad de Talca, Casilla 747, Talca 3460000, Chile. schmeda@utalca.cl.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Schmeda-Hirschmann
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D002677:Chile; D002851:Chromatography, High Pressure Liquid; D036381:Diarylheptanoids / Q000737:chemistry / Q000494:pharmacology; D004224:Diterpenes / Q000737:chemistry / Q000494:pharmacology; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology; D010936:Plant Extracts / Q000032:analysis* / Q000737:chemistry / Q000494:pharmacology; D011429:Propolis / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D036381:Diarylheptanoids; D004224:Diterpenes; D010636:Phenols; D010936:Plant Extracts; D011429:Propolis
keywords: antimicrobial; diarylheptanoids; flavonoids; phenolics; poilaneic acid; propolis