In vitro inhibition of Helicobacter pylori and interaction studies of lichen natural products with jack bean urease. (12th March 2018)

• Record Type: Journal Article
• Authors: Lage, Tiago C. A.; Maciel, Thamilla Maria S.; Mota, Yane C. C.; Sisto, Francesca; Sabino, José R.; Santos, Josué C. C.; Figueiredo, Isis M.; Masia, Carla; de Fátima, Ângelo; Fernandes, Sergio A.; Modolo, Luzia V.
• Is Part Of: New journal of chemistry. Volume 42:Number 7(2018)
• Page Start: 5356
• Page End: 5366
• Publication Date: 2018-03-12
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/c8nj00072g
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : The interaction between lichen metabolites and jack bean urease was investigated by molecular spectroscopy at pH 7.4 and kinetics assay. Abstract : The interaction of ( S )-(−)-usnic acid (2 ) and fumarprotocetraric acid (3 ), isolated from Cladonia rappii (lichen), and commercial ( R )-(+)-usnic acid (1 ) with urease was investigated in vitro by molecular spectroscopy at pH 7.4 and kinetics experiments using jack bean type III urease. All lichen compounds tested interact with urease by a statistical quenching mechanism forming non-fluorescent complexes that change the native protein structure. Formation of complexes was spontaneous and stabilized mainly by electrostatic forces, in which the interaction magnitude was determined to be3 <2 <1 . Compound2, whose tridimensional structure is disclosed here, acts as a mixed inhibitor while compounds1 and3 function as competitive ones. The ( R )-(+)-UA (1 ) is the most efficient lichen metabolite with respect to impairment of the growth of five H. pylori strains. The minimum inhibitory concentrations (MIC) for the lichen metabolites tested were lower (from 2- to 7.8-fold) than those of omeprazole (reference drug) against all H. pylori strains tested. Overall, the lichen metabolites1–3 are promising lead compounds for the design of more efficient urease inhibitors for the treatment of H. pylori infections.