Determination of flavonoids, polyphenols and antioxidant activity of Tephrosia purpurea: a seasonal study

The findings of this study confirmed that the metabolism and production of flavonoids in T. purpurea are vigorously affected by seasonal factors. Significant differences were observed in the TPC, TFC and flavonoid glycoside composition in the 95% ethanolic as well as 50% hydro-alcoholic extracts of T. purpurea collected in different seasons. Since the 95% ethanolic extract of the August sample (TP-3), which also happens to be its flowering season, exhibited the highest TPC, TFC and antioxidant activities in both DPPH and phosphomolybdate assays as well as contained the highest content of all flavonoids, it could be recommended as the optimal season of harvesting T. purpurea with respect to its pharmaceutically important constituents, i.e., flavonoids.