title: Anti-Helicobacter pylori activity of some newly synthesized derivatives of xanthone.
abstract: A series of 20 xanthone derivatives was synthesized and evaluated for anti-Helicobacter pylori (H. pylori) activity. Qualitative and quantitative in vitro tests using the Kirby-Bauer method (agar disc-diffusion method) were performed. The tested compounds were screened against clarithromycin- and/or metronidazole-resistant strains of H. pylori. As a reference, Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacterial strains were examined. On the basis of microbiological assays, xanthones can be considered as potential anti-H. pylori agents. They displayed significant activity against the examined strains, which was higher against the bacteria resistant to metronidazole than clarithromycin. The lowest MIC values ranging up to 20 mg l-1were observed for the following compounds: 3, 4, 8, 9, 12, 19 (against the metronidazole-resistant strains) and the compound 10 (against the clarithromycin-resistant strain). These preliminary results for screening of xanthone derivatives form a part of an ongoing study of the structure-activity relationships of a large group of compounds. Microbiological assays will be conducted afterwards to determine the mechanism of xanthones' action against H. pylori.
authors.affiliation: Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland.
authors.forename: Karolina
authors.initials: K
authors.lastname: Klesiewicz
authors.affiliation: Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland.
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Karczewska
authors.affiliation: Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland.
authors.forename: Alicja
authors.initials: A
authors.lastname: Budak
authors.affiliation: Department of Bioorganic Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland.
authors.forename: Henryk
authors.initials: H
authors.lastname: Marona
authors.affiliation: Department of Bioorganic Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland.
authors.forename: Natalia
authors.initials: N
authors.lastname: Szkaradek
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D017291:Clarithromycin / Q000494:pharmacology; D016480:Helicobacter pylori / Q000187:drug effects*; D008795:Metronidazole / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D013211:Staphylococcus aureus / Q000187:drug effects; D013329:Structure-Activity Relationship; D044004:Xanthones / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D044004:Xanthones; D008795:Metronidazole; D017291:Clarithromycin