Available online at www.derpharmachemica.com Scholars Research Library Der Pharma Chemica, 2010, 2(1): 1-13 (http://derpharmachemica.com/archive.html) ISSN 0975-413X 1 www.scholarsresearchlibrary.com A QSAR Study of the Activity of Some Fluorinated Anesthetics Fakhr M. Abu-Awwad Chemistry Department, Islamic University of Gaza, Box 108 – Gaza, Palestine ______________________________________________________________________________ Abstract The density functional B3LYP was used to computationally investigate the anesthetic activity of 19 different fluorinated anesthetics. The structures were optimized at 6-311G** basis set and subsequent quantitative structure–activity relationship investigation using CODESSA package was employed to correlate the molecular anesthetic activities with several computed descriptors. In the computed models, the activity was mainly attributed to both quantum mechanical and electrostatic observables. Statistically, the most significant correlation was a four- parameter equation with good statistical parameters; correlation coefficients, R 2 = 0.985, cross-validated correlation coefficients, R 2 CV = 0.972, F = 225.096, and S 2 = 0.227. The obtained model is good enough to be used to estimate the activities of the fluorinated anesthetics. Keywords: anesthetic; flouro-compounds; B3LYP; CODESSA; QSAR. ______________________________________________________________________________ Introduction Quantitative structure – activity/property relationships (QSAR/QSPR) have been widely used to correlate pharmacological activities of various chemical compounds with computed related observables [1, 2]. A primary step in constructing the QSAR/QSPR models is finding one or more molecular descriptors that represent variation in the structural property of the molecules. The concluded mathematical equations relate the computed structural features to the molecular therapeutic or biological activities. Usually, these equations provide vital information for further development of the drugs design and enhance the capacity to estimate the property of other molecules or to find the parameters affecting the potency. CODESSA has been successfully employed in several QSAR studies [3,4]. The main advantage of CODESSA over other packages in these applications is the easy generation of a large number of theoretical descriptors which code the chemical structure in numerical format. For such analysis, quantum-chemical methods are used to calculate physicochemical parameters that