Antibacterial profiling of Sempervivum tectorum L. (common houseleek) leaves extracts using high-performance thin-layer chromatography coupled with chemometrics

Sempervivum tectorum L. (common houseleek) ( Crassulaceae ) has been traditionally used since ancient times for the treatment of various medical conditions, including ear and bladder infections of bacterial origin. The main aim of the current study is to investigate the antibacterial activity of S. tectorum leaf extracts using high-performance thin-layer chromatography–direct bioautography (HPTLC–DB) combined with chemometrics. This work presents a novel approach for the investigation of the antibacterial activity of S. tectorum leaf extracts on four Gram-positive ( Bacillus subtilis , Micrococcus lysodeikticus , methicillin-resistant Staphylococcus aureus (MRSA), and Staphylococcus aureus ) and two Gram-negative bacteria ( Escherichia coli and Klebsiella pneumoniae ) using HPTLC–DB bioassays. Gram-negative bacterial strains showed higher sensitivity in comparison with Gram-positive bacterial ones, due to the fact that numerous bands that represent active compounds are observed on biochromatograms. Principal component analysis (PCA) confirmed the discrimination between Gram-positive and Gram-negative biochromatograms by highlighting the main markers responsible for the separation. The proposed technique represents a fast and efficient way to separate and identify compounds with antibacterial activity in complex natural matrices.