From Crotalaria juncea seed, ethanolic extraction yielded the alkaloids riddelline, seneciphylline and senecionine. Subsequent methanolic extraction of the ethanol-exhausted material resulted in the isolation of a new alkaloid designated junceine, together with trichodesmine (previously reported from Trichodesma incanum), and an optically inactive amino acid identified as β-hydroxy-N-methyl-m-norvaline A. Ethanolic extraction of the seed gave a 0.0039% yield of alkaloidal material, with separation achieved via partition chromatography. The methanolic extract was processed to separate components, including the salt-like amino acid, and further chromatographed on Florisil to isolate junceine and trichodesmine. The identity of riddelline, seneciphylline and senecionine was confirmed by melting points, mixture melting points with authentic samples, optical rotations, Rf values and infrared spectra. Junceine, a new alkaloid, was characterized by its empirical formula (C₁₈H₂₇NO₇), melting point (191-192°C), optical rotation, and differentiation from similar alkaloids (jacoline, sceleratine) via solubility, physical constants and Rf values. Trichodesmine was identified by comparison of melting point, rotation, methiodide derivative and structural resemblance to other Crotalaria alkaloids. The amino acid (C₆H₁₃NO₃) was identified through spectral analysis (infrared bands indicating secondary amine, hydroxyl group), chemical reactions (periodic acid and lead tetraacetate oxidation), formation of a copper salt, and comparison with an authentic sample of β-hydroxy-N-methyl-m-norvaline A (identical infrared spectra, no melting point depression). Variations in alkaloid yields and composition between two seed batches may be attributed to growth stage, season and collection location. Structural investigations of trichodesmine and junceine are pending further report.