Antibacterial agents from the seeds of Peucedanum zenkeri L. [Umbelliferae]

ABSTRACT

In a search for natural substances with potential for the treatment of typhoid fevers and urogenital infections, the methylene chloride extract of the seeds of Peucedanum zenkeri was investigated. The extract was subjected to column chromatography leading to the isolation of seven compounds. Their structures were determined using modern 2D NMR techniques and by comparison with published NMR data. These compounds were tested against Salmonella typhi, Salmonella paratyphi B, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus aureus, using both agar diffusion and broth dilution techniques. The compounds isolated were umbelliprenin [1], prangenin [2], imperatorin [3], isopimpinellin [4], bergapten [5], cnidilin [6] and stigmasterol [7]. Among the above seven compounds, only two [1 and 2] exhibited antibacterial activity. For compound 1, the MIC value was 300 micro g/ml against P. aeruginosa, S. aureus, S. typhi and S. paratyphi B. For compound 2, the MIC values varied between 200 and 300 micro g/ml against all the bacteria strains tested. These data suggest that Peucedanum zenkeri seed extract contains antibacterial agents which are active against Salmonella species causing typhoid and paratyphoid fevers, and some bacteria strains causing urogenital infections. The antibacterial activity of compound 2 appears to be due to the epoxide group present in its structure