Antitubercular constituents from the roots of Engelhardia roxburghiana.

Three new compounds, engelhardione, (-)-5-hydroxy-4-methoxy-1-tetralone, and 3-methoxycarbonyl-1,5-dihydroxyanthraquinone, together with twelve known compounds have been isolated from the roots of Engelhardia roxburghiana. The structures of these new compounds were determined through spectral analyses. Engelhardione, 3-methoxyjuglone, and (-)-4-hydroxy-1-tetralone showed antitubercular activities with MIC values=3.125, 3.125, and 6.25 microg/mL against Mycobacterium tuberculosis 90-221,387, respectively, and with MIC values=0.2, 0.2, and 4.0 microg/mL against M. tuberculosis H37Rv, individually.