Characterization and antibacterial activity of phthalides from the roots of the medicinal herb Levisticum officinale W.D.J. Koch.

A new phthalide, namely 7-methoxy-3-propylidenephthalide (1), along with two known compounds (2, 3) were isolated from the roots of the edible herb Levisticum officinale W.D.J. Koch, commonly known as lovage and well known in traditional medicine for its spasmolytic and diuretic effects. The structure of the new compound was established by HRMS and 1D & 2D NMR (1H 1H COSY, HMQC, and HMBC) spectroscopic analysis. All compounds are reported for the first time from L. officinale. Compounds 1-3 were tested against two Gram negative (Escherichia coli, Pseudomonas aeruginosa) and two Gram positive (Staphylococcus aureus and vancomycin-resistant Enterococcus [VRE] faecium) bacteria strains. Compound 3 was active against S. aureus, E. coli and vancomycin-resistant E. faecium with MIC values of 16, 64 and 128 μg/mL, respectively.