Two new prenylated flavonoids, purpuritenin and purpureamethide, have been characterized from the seeds of Tephrosia purpurea together with the known compounds pongamol, karanjin and lanceolatin B. Tephrosia Pers. (Galegeae, Lotoideae, Leguminosae) is a large tropical and sub-tropical genus of some 300 species[1]. Earlier phytochemical screening [2] of a number of species have revealed the presence of rotenoids, isoflavones, flavanones, chalcones, flavonols and flavones. Within the group of flavones, 5,7-oxygenated and 7-oxygenated compounds which are characterized by the presence of a C-8 prenyl unit are well known. In many cases, these prenylated flavones have undergone further substitution and cyclization leading to complex molecules. T. purpurea Pers. occurs throughout the Indian subcontinent. This species has been reported to contain a number of rotenoids [3] besides pongamol [4], isolonchocarpin[5], karanjin, lanceolatin B, kanjone and sitosterol[6]. Recent reports [7] indicating insecticidal and repellent properties of the seed extract of this plant prompted us to undertake a study of the active principle from this species. We now report the occurrence of five flavonoids; pongamol (1), karanjin (2), lanceolatin B (3) and two new compounds purpuritenin (4) and purpureamethide (5) from the seeds of T. purpurea. Pongamol (1) was identified by complete spectral analysis (UV, IR, ¹H NMR, MS) and comparison with an authentic sample. Karanjin (2) and lanceolatin B (3) were also characterized by spectral data and comparison with authentic samples. Purpuritenin (4) was analysed for C₁₉H₁₆O₃ ([M]⁺ 292), [α]ᴰ CHCl₃ 0°. The structure was assigned on the basis of spectral data. ¹H NMR of 4 was very similar to ovalitenin A isolated from Milletia ovalifolia [8] except for an additional aromatic methyl group in the former compound. Alkaline hydrolysis of 4 gave p-toluidic acid, mp 182-183°, thus confirming parasubstitution in ring A with a methyl at C-4 and the structure of purpuritenin as 4-methyl-2'-methoxy-(3',4',2'',3'')furano-chalcone. Prenylated flavonoids [2] are very well known in the literature but to our knowledge, this is a rare example of a methylated chalcone, which may perhaps be a secondary fungal metabolite of the seeds. Purpureamethide (5) analysed for C₁₈H₁₄O₃ ([M]⁺ 264), [α]ᴰ CHCl₃ 0°. Absence of Me-4 in the ¹H NMR and a ketone band in the IR spectrum along with an appearance of a new olefinic proton as compared to 4 led us to structure 5, 1'-cinnamylidene-2'-methoxy-(3',4',2'',3'')furanocyclohexa-2,5-diene. Absorption at higher wavelength (374 nm) also suggested extended conjugation. This structure was supported by the presence of a peak at m/z 185 representing the loss of ring A only and hence confirming the absence of any substitution in ring A. Quinone methides occur in nature both as fungal metabolites, and as wood pigments [9]. Purpureamethide is probably related to the cinnamyl phenols which co-occur with the neoflavonoids in the closely related genera Dalbergia and Machaerium [10]; A new lupin alkaloid, (-)-N-ethylcytisine, was isolated from the fresh flowers of Echinosophora koreensis. Its structure has been confirmed by spectroscopic data and by direct comparison with a synthetic sample prepared from (-)-cytisine and ethylbromide.