title: Compounds of Alpinia katsumadai as potential efflux inhibitors in Mycobacterium smegmatis.
abstract: Efflux pumps are one of the well established mechanisms that contribute to antibiotic resistance in bacteria, such as mycobacteria. As a result, the identification of efflux pump inhibitors is an attractive target in antimicrobial therapy. The isolated compounds, three diarylheptanoids, trans,trans-1,7-diphenylhepta-4,6-dien-3-one (1), (5R)-trans-1,7-diphenyl-5-hydroxyhept-6-en-3-one (2), (3S,5S)-trans-1,7-diphenylhept-1-ene-3,5-diol (3) and the flavonoid pinocembrin (4), from Alpinia katsumadai, Zingiberaceae, were examined for their antimycobacterial activity and their synergistic effects with different antibiotics against M. smegmatis mc(2) 155. Furthermore, these compounds were evaluated as potential EtBr efflux inhibitors. Although they showed weak antimycobacterial activities (MIC ≥ 64 mg/L), especially compound 1 revealed a significant activity on the EtBr accumulation and efflux as well as a synergistic effect in combination with rifampicin.
authors.affiliation: Institute of Pharmaceutical Sciences, Department of Pharmacognosy, Karl-Franzens-University Graz, Universitätsplatz 4/I, A-8010 Graz, Austria.
authors.forename: Barbara
authors.initials: B
authors.lastname: Gröblacher
authors.forename: Olaf
authors.initials: O
authors.lastname: Kunert
authors.forename: Franz
authors.initials: F
authors.lastname: Bucar
mesh_terms: D032429:Alpinia / Q000737:chemistry*; D000904:Antibiotics, Antitubercular / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000995:Antitubercular Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D036381:Diarylheptanoids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D020102:Mycobacterium smegmatis / Q000187:drug effects* / Q000254:growth & development; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D012639:Seeds / Q000737:chemistry
chemical_list: D000904:Antibiotics, Antitubercular; D000995:Antitubercular Agents; D036381:Diarylheptanoids; D010936:Plant Extracts