Two novel antibacterial constituents isolated from the pericarps of Zanthoxylum schinifolium Siebold & Zucc

Two previously undescribed compounds (1 and 2), together with nineteen reported constituents (3–21) were obtained from the pericarps of Zanthoxylum schinifolium Siebold & Zucc. Structural characterisation of all isolated metabolites were fully elucidated by FT–IR, UV–Vis, HRESI-MS and NMR. Antibacterial screening of all purified metabolites was conducted versus three pathogenic strains: Staphylococcus aureus, Bacillus subtilis, and Escherichia coli. Berberine and cefotaxime sodium were set as positive controls, and MIC values were applied to quantify antibacterial effects. Compounds 1, 7 and 19 displayed potent inhibitory action towards E. coli, with respective MIC of 12.5, 25 and 25 μg/mL. Compounds 2 and 17 exhibited obvious suppression towards S. aureus at MIC 12.5 μg/mL, and compounds 5 and 11 had potent inhibition on B. subtilis with the same MIC 12.5 μg/mL. Notably, undescribed compound 1 presented remarkable anti-E. coli activity (MIC = 12.5 μg/mL), which was better than berberine (MIC = 25 μg/mL).