BIOCHEMICAL ANALYSIS AND EVALUATION OF ANTIMICROBIAL PROPERTIES OF THEAFLAVINS AND FLAVONOIDS RICH EXTRACT (TFE) AND ITS SILVER NANOCONJUGATES: A COMPARATIVE STUDY

Black tea, the most widely consumed aromatic non-alcoholic beverage second to water, is prepared by boiling cured leaves of Camellia sinensis. It is reported that black tea contains plenty of bioactive constituents, including complex polyphenols like theaflavins (TF₂A, TF₂B, TF₃) and thearubigins that exhibit a wide range of pharmacological properties and also contribute to its quality and bioactivity. The present study aims at biochemical characterization and evaluation of antimicrobial activity of Theaflavins and Flavonoids rich Extract (TFE) and their silver nanoconjugates. TFE was obtained by steeping black tea in boiling water at 90 °C for 5 min, subsequently extracted with ethyl acetate and dried for further use. The biochemical characterization of TFE was done using HPLC and other spectrophotometric methods. Next, silver nanoconjugates of the TFE were prepared using a green synthesis route, and antimicrobial property was evaluated with respect to its non-conjugated form. It was observed that the TFE is an antioxidant rich fraction and helps in metal-nanoparticle synthesis efficiently. The study highlighted that, in maximum cases, nanoconjugates gave better results than their non-conjugated form.