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 H37Rv with minimum inhibitory concentration (MIC) values of 125 mg/mL. The MIC values of
M. tuberculosis clinical isolates ranged from 125 mg/mL to >250 mg/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.