Investigation of antimicrobial model of Hemsleya pengxianensis W.J.!Chang and its main active component by metabolomics technique

Aim of the study: H.pengxianensi is a native plant in China. Dihydrocucurbitacin F-25-O-acetate is one of the major chemical components in H.pengxianensis. In this investigation, we attempted to quantify the content of dihydrocucurbitacin F-25-O-acetate in H.pengxianensis and find the possible antibacterial mode of dihydrocucurbitacin F-25-O-acetate and H.pengxianensis. Material and methods: First, the content of dihydrocucurbitacin F-25-O-acetate was quantified by HPLC. Then, metabolic profiles of Staphylococcus aureus treated by dihydrocucurbitacin F-25-O-acetate, extract of H.pengxianensis and nine antibacterial substances with the known modes of action were acquired by HPLC/DAD/ESI-MS. Principal component analysis was carried out upon all metabolic profiles to classify those drugs according to their mechanisms. Results and conclusion: The HPLC result show the content of dihydrocucurbitacin F-25-O-acetate in H.pengxianensis (5.3 +/- 0.4 mg/g). From the result obtained by principal component analysis, dihydrocucurbitacin F-25-O-acetate was found to be the component playing the main antimicrobial roles on Staphylococcus aureus in H.pengxianensis and the possible antibacterial mode of dihydrocucurbitacin F-25-O-acetate and H.pengxianensis may be to inhibit cell wall synthesis. (C) 2007 Published by Elsevier Ireland Ltd.