604DETERMINATION OF BINDING ENERGY OF THE FLAVONOIDS PRESENT IN ERYTHRINA VARIGATA BY DFT METHODFlavonoids isolated from Erythrina Varigata species were found to exhibit various pharmacological properties. In order to find the lead compounds among the thirteen flavonoids selected for our work, binding energy determination were carried out by DFT method using Gaussian software. Binding energies were calculated by B3LYP and HF methods using three basis sets like STO-3G, 3-21G, 6-31G. Among the thirteen flavonoids, Vogelin- I was found to have good binding energy by both the method. B3LYP method the binding energies were found to be STO-3G (-1472.3907), 3-21G (-1472.3907) and 6-31G (-1491.2817). Binding energy by STO-3G (-1474.1990), 3-21G (-1474.1990) and 6-31G (-1481.8226) were observed by HF method. These results showed that the flavonoid Vogelin-I was found to have very good binding energy and stability. Hence this may serve as a very good drug in futuremrs.valliravichandran@gmail.comResearch652015Erythrina Varigata,Flavonoids,DFT,B3LYP ,HF methodsG. Valli, S. Geetha Department of Chemistry, S.F.R. College, Sivakasi, Tamilnadu, India,Associate Professor & Head, Department of Chemistry, The Standard Fireworks Rajaratnam College for Women, Sivakasi- 626123, Virudhunagar District, Tamilnadu State, India