Evaluation of Antibacterial and Anti-biofilm Activities of Cinchona Alkaloid Derivatives against Staphylococcus aureus

• Published in: Natural product communications 2012-09, Vol.7 (9), p.1173-1176
• Main Authors: Skogman, Malena E., Kujala, Janni, Busygin, Igor, Leino, Reko, Vuorela, Pia M., Fallarero, Adyary
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - pharmacology; Biofilms - drug effects; Cinchona Alkaloids - pharmacology; Staphylococcus aureus - drug effects; Staphylococcus aureus - physiology
• ISSN: 1934-578X; 1555-9475
• DOI: 10.1177/1934578X1200700917

Bacterial biofilms are resistant to most of the commonly available antibacterial chemotherapies. Thus, an enormous need exists to meet the demands of effective anti-biofilm therapy. In this study, a small library of cinchona alkaloids, including the naturally occurring compounds cinchonidine and cinchonine, as well as various synthetic derivatives and analogues was screened for antibacterial and anti-biofilm activity against the Staphylococcus aureus biofilm producing strain ATCC 25923. Two methods were used to evaluate activity against biofilms, namely crystal violet staining to measure biomass and resazurin assay to measure biofilms viability. Cinchonidine was found to be inactive, whereas a synthetic derivative, 11-triphenylsilyl-10,11-dihydrocinchonidine (11-TPSCD), was effective against planktonic bacteria as well as in preventing biofilm formation at low micromolar concentrations. Higher concentrations were required to eradicate mature biofilms.