A new long-chain alkene, dotriacont-1-ene (1), was isolated from the leaves of Pourthiaea lucida, together with twelve known compounds. The structure of this new compound was determined by NMR and mass-spectrometric analyses. Among the isolated compounds, alpha-tocospiro A (2), alpha-tocopheryl quinone (4), and (E)-phytol (5) exhibited antituberculosis activities (MICs <or=30 microg/ml) against Mycobacterium tuberculosis H(37)Rv in vitro.