We have presently studied the alkaloidal content of Illigera pentaphylla Welw. collected in southwestern Nigeria, from which we have isolated the new amorphous phenanthrene alkaloid, thaliporphinemethine (1), C21H25NO4. The 1H-nmr spectrum of thaliporphinemethine in CDCl3 solution at 360 MHz showed three aromatic proton singlets (including one at δ 9.27 representing H-5), three methoxyl singlets at δ 3.92, 4.04, and 4.08, a hydroxyl function at C-4 (as a methoxyl group there would adsorb upfield in δ 3.78-3.90), two doublets at δ 7.50 and 7.75 due to H-9 and H-10, and a six-proton singlet at δ 2.41 denoting a dimethylamino group. A strong uv bathochromic shift in basic solution confirmed the presence of a phenolic function. The mass spectrum exhibited a small molecular ion m/z 355 and a base peak m/z 58 due to the dimethyliminium cation. Fourteen known alkaloids were also found, eight of which were aporphines (including (+)-actinodaphnine, (+)-lindcarpine, (+)-boldine, (+)-norboldine, (+)-N-methylindcarpine, (+)-laurotetanine, (+)-nordicentrine, and (+)-laurelliptine) while the remaining six were oxoaporphines (including lysicamine, oxonantenine, oxocrebanine, dicentrinone, lanuginosine, and atheroline).