Bioactivity of secondary metabolites from transgenic AtCKX1 centaury (Centaurium erythraea rafn.) plants grown in vitro

Abstract

Microbes causing numerous and the most diverse infections in humans worldwide. The increasing use of antibiotics and antifungal drugs have led to development of multidrug-resistant pathogens. Thus, there is a need for discovering novel and effective tools in control of pathogenic microorganisms. For many years plants represent important source of numerous chemical compounds. Common centaury, Centaurium erythraea Rafn. (syn. C. umbellatum Gillib and C. minus Moench), represent the best known and the most investigated medicinal plant species of genus Centaurium. Centaury has been used for centuries in traditional medicine. Secondary metabolites, bitter secoiridoid glucosides (gentiopicrin, swertiamarin and sweroside) and xanthones (eustomin and demethyleustomin), are responsible for therapeutically properties of centaury. AtCKX transgenic centaury plants grown in vitro produced the same secondary metabolites as wild type centaury plants grown in nature. The aim of this study was to investigate antibacterial and antifungal activity of centaury methanol extracts and pure secoiridoid and xanthone compounds on four Gram positive, four Gram negative bacteria and eight species of microfungi. All tested methanol extracts of control and transgenic AtCKX centaury shoots and roots showed better antibacterial activity, while pure compounds (gentiopicrin, swertiamarin, eustomin and demethyleustomin) showed better antifungal activity. The results obtained in this work suggest that centaury methanol extracts and pure compounds represent potential antimicrobials confirming the possibility of using these compounds in agronomy, veterinary, medicine or food industry.