BIOSYNTHESIS AND BIOACTIVITY OF SILVER NANOBIOCONJUGATES FROM GRAPE (VITIS VINIFERA) SEEDS AND ITS ACTIVE COMPONENT RESVERATROL

The seeds of Vitis vinifera have been shown to have antioxidant, anticancer and antimicrobial properties due to the presence of rich bioactive phenolic components like resveratrol. The research deals with the synthesis of silver nanobioconjugates from the methanolic extract of grape seeds and the pure compound resveratrol. The presence of resveratrol was confirmed by HPLC analysis in methanolic extract of various parts of grape fruits such as skin, pulp and seeds of two varieties (pink and black). As higher amount of resveratrol was present in the seed extract of pink grapes, it was selected for the silver nanobioconjugate synthesis. Various conditions were applied to influence the rapid reduction of Ag⁺ to Ag^ο, such as microwave heating, water bath heating, sunlight exposure and incubation at 37^οC for nanobioconjugate synthesis. The reduction of silver ions was confirmed by color changes, adsorption spectroscopy (280-800nm) and percentage yield. Among the four different methods, sunlight exposure proved to be rapid in the synthesis and the yield of nanobioconjugates was also high. Therefore, this method was chosen for the synthesis of silver nanobioconjugates using resveratrol. The bioactivity of the synthesized silver nanoconjugates were also evaluated through antimicrobial activity. The results showed that the resveratrol in grape seeds extract can act as good reductant and stabilizer for the silver nanobioconjugate synthesis, which also exhibits potent bioactivity.