A new benzoic acid derivative from Piper diospyrifolium and its anti-Mycobacterium tuberculosis activity

The extraction by supercritical fluid (SFE-CO2) from leaves of Piper diospyrifolium and chromatographic column purification afforded the isolation of a new benzoic acid derivative 4-methoxy-3-[(E)-3-methyl-1,3- butadien-1-yl]-5-(3-methyl-2-buten-1-yl)-benzoic acid (1). The chemical structure was elucidated on the basis of spectroscopic methods and comparison with literature data. SFE-CO2 extracts and (1) were tested for their anti-Mycobacterium tuberculosis activities and cytotoxicities in J774G.8 macrophages. The compound (1) and SFE-CO2 extracts exhibited moderate activities against M. tuberculosis H(37)Rv with minimum inhibitory concentration (MIC) values of 125 mu g/mL. The MIC values of M. tuberculosis clinical isolates ranged from 125 mu g/mL to >250 mu g/mL. The cytotoxicities results showed a selectivity index range from 0.6 to 1.0. Additional studies in structure activity-relationship as well as synergistic activity with antituberculous drugs should be conducted for a better evaluation of anti-mycobacterial activity of this compound. (C) 2014 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.