title: Traditionally used medicinal plants against uncomplicated urinary tract infections: Are unusual, flavan-4-ol- and derhamnosylmaysin derivatives responsible for the antiadhesive activity of extracts obtained from stigmata of Zea mays L. against uropathogenic E. coli and Benzethonium chloride as frequent contaminant faking potential antibacterial activities?
abstract: The dried stigmata from Zea mays L. are used traditionally for the treatment of uncomplicated urinary tract infections. A recent screening has indicated that hydroalcoholic extract of the herbal material inhibits the adhesion of uropathogenic Escherichia coli (UPEC) to T24 bladder cells. For verification of these data EtOH-water (1:1) extracts from 4 different batches of Maydis stigmata were investigated. Within an in vitro adhesion assay (UPEC strain 2980 and human T24 bladder cells) a dose-dependent antiadhesive activity against UPEC was verified (IC50 1040μg/mL). Bioassay guided fractionation of M. stigmata, batch S1, by EtOH-water extraction, followed by chromatography on Sephadex LH20 revealed two active fractions (I and XI). Further purification of fraction I and structure elucidation of the isolated compound revealed the presence of significant amounts of the biocide benzethonium chloride as contaminant. Benzethonium chloride was also identified in subsequent investigations in 2 different batches of M. stigmata. The presence of such nondeclared and illegal contaminants in the herbal raw material market has to be discussed intensively. From benzethonium-free raw material (batch S2) as well as from batch S1 fraction XI was further fractionated by MPLC and preparative HPLC, leading to a still complex subfraction XIG, which was analyzed by UHPLC/+ESI-QTOF-MS analysis. Advanced data processing and species-metabolite relationship database revealed the tentatively existence of the unusual C-glycosidic flavones derhamnosylmaysin (6), 3'-deoxyrhamnosylmaysin (4), 3'-O-methylderhamnosylmaysin (3), apiferol (2) and alternanthin (8) which might be related to the antiadhesive activity of this subfraction against UPEC.
authors.affiliation: University of Münster, Institute of Pharmaceutical Biology and Phytochemistry, Corrensstrasse 48, D-48149 Münster, Germany.
authors.forename: Nasli
authors.initials: N
authors.lastname: Rafsanjany
authors.affiliation: University of Münster, Institute of Pharmaceutical Biology and Phytochemistry, Corrensstrasse 48, D-48149 Münster, Germany.
authors.forename: Jandirk
authors.initials: J
authors.lastname: Sendker
authors.affiliation: University of Münster, Institute of Pharmaceutical Biology and Phytochemistry, Corrensstrasse 48, D-48149 Münster, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Lechtenberg
authors.affiliation: University of Münster, Institute of Pharmaceutical Biology and Phytochemistry, Corrensstrasse 48, D-48149 Münster, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Petereit
authors.affiliation: University of Münster, Institute of Pharmaceutical Biology and Phytochemistry, Corrensstrasse 48, D-48149 Münster, Germany.
authors.forename: Birte
authors.initials: B
authors.lastname: Scharf
authors.affiliation: University of Münster, Institute of Pharmaceutical Biology and Phytochemistry, Corrensstrasse 48, D-48149 Münster, Germany. Electronic address: ahensel@uni-muenster.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Hensel
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001422:Bacterial Adhesion / Q000187:drug effects; D001558:Benzethonium / Q000494:pharmacology; D002460:Cell Line; D047309:Flavones / Q000494:pharmacology*; D035264:Flowers / Q000737:chemistry; D006801:Humans; D015394:Molecular Structure; D010936:Plant Extracts / Q000494:pharmacology; D010946:Plants, Medicinal / Q000737:chemistry*; D001743:Urinary Bladder / Q000166:cytology; D014552:Urinary Tract Infections / Q000188:drug therapy; D056689:Uropathogenic Escherichia coli / Q000187:drug effects*; D003313:Zea mays / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D047309:Flavones; D010936:Plant Extracts; D001558:Benzethonium
keywords: Adhesion; Benzethoniumchloride; Bladder cells; Maysin; Uropathogenic E. coli; Zea mays