Colchicum szovitsii Fisch. et Mey. is known as a colchicine-containing plant; however, its alkaloid content has not been investigated in detail. By the usual method, 3 kg of the plant (epigeal and hypogeal parts) in the fruit-bearing period was extracted with ethanol, giving 0.11% of a weak-base fraction and 0.04% of a strong-base fraction. The weak-base fraction was separated into alkali-soluble and alkali-insoluble components (yields 0.06 and 0.05%, respectively). The alkali-insoluble mixture contained colchicine and nontropolone compounds, while the alkali-soluble part included 2-demethylcolchicine, 3-demethyl-β-lumicolchicine, an unidentified compound, 2-dimethylcolchiceine, and colchiceine. Preparative thin-layer chromatography of 700 mg of the alkali-insoluble mixture isolated 200 mg of a base (szovitsamine, I) with composition C₂₂H₂₇O₅N, melting point 188-190°C (from ether), [α]ᵈ²⁰ +86° (c 1.4; chloroform), and Rf 0.31. Its UV spectrum with absorption maxima at 258 and 287 nm (log 4.33, 4.07) indicated it belongs to the homoaporphine compound group. The NMR spectrum showed signals of four methoxy groups (nine-proton singlet at 3.82 ppm and three-proton singlet at 3.50 ppm), a N-methyl group (three-proton singlet at 2.33 ppm), and two benzene-ring protons isolated from one another (one-proton singlets at 6.37 and 6.64 ppm). Methylating szovitsamine with diazomethane gave a O-methyl ether identical with di-O-methylfloramultine, showing szovitsamine has substituents in the C₂, C₃, C₄, C₅, and C₆ positions, with one hydroxy group and others methoxy groups. Analysis of its mass spectrum (characteristic peaks with m/e 385 (M⁺), M-15, M-17, M-31 (100%), and M-43) indicated the C₄ position is substituted by a hydroxy group. Thus, szovitsamine was proposed to have the structure of 4-hydroxy-2,3,5,6-tetramethoxyhomoaporphine. On the basis of the positive sign of the specific rotation and literature information, compound (I) corresponds to the absolute R configuration.