A database consisting of 23 tripeptides was used to study the quantitative relationships between electric surface potential descriptors and antioxidant activity QESARs. The important structural descriptors SaaNH_acnt, SsOH_acnt, SaaN, SaaN_acnt, SsssCH, SaaaC, SsNH3p, SdO, SdO_acnt were selected for constructing the linear models QESARs with genetic algorithm. The best 4-variable linear model QESARlinear including the structural descriptors SaaN, SdO, SdO_acnt and SsOH_acnt was constructed. The quality QESARlinear was exhibited in statistical values R2 fitness of , standard error of estimation SE of , F-stat of , R2 test of . The non-linear model as neural network model QESARneural I(4)-HL(3)-O(1) with R2 fitness of was built by using structural descriptors in QESARlinear model. The antioxidation activities of tripeptides resulting from QESARlinear and QESARneural model were pointed out in values MARE, % of and , respectively. | QESAR study tripeptide analogues as antioxidation agents Tạp chí Đại học Thủ Dầu Một, số 3(5) – 2012 QESAR STUDY OF TRIPEPTIDE ANALOGUES AS ANTIOXIDATION AGENTS Nong Thi Hong Duyen(1) – Pham Van Tat(2) (1) Hue University of Science; (2) Thu Dau Mot University ABSTRACT A database consisting of 23 tripeptides was used to study the quantitative relationships between electric surface potential descriptors and antioxidant activity QESARs. The important structural descriptors SaaNH_acnt, SsOH_acnt, SaaN, SaaN_acnt, SsssCH, SaaaC, SsNH3p, SdO, SdO_acnt were selected for constructing the linear models QESARs with genetic algorithm. The best 4-variable linear model QESARlinear including the structural descriptors SaaN, SdO, SdO_acnt and SsOH_acnt was constructed. The quality QESARlinear was exhibited in statistical values R2fitness of , standard error of estimation SE of , F-stat of , R2test of . The non-linear model as neural network model QESARneural I(4)-HL(3)-O(1) with R2fitness of was built by using structural descriptors in QESARlinear model. The antioxidation activities of tripeptides resulting from QESARlinear and QESARneural model were pointed out in values MARE, % of and , respectively. Keywords: QESARs model, multiple regression, neural network and antioxidation tripeptides * 1. Introduction xidation activities QESAR may indicate The antioxidation compounds prevent quantitatively change of biological activity the biological and chemical substances from or physicochemical properties corres- radical-induced oxidation damage [4]. The ponding to composition of amino acids in hydrolysis from various proteins, such as peptide chain [2], [3]. soybean, casein, bullfrog, royal jelly, venison, This work reports the use of r-lactalbumin, myofibrillar, rice endosperm, multivariate regression and neuro-fuzzy have been shown to have antioxidant technique with genetic .
