Abstract:The aim of the paper is to present the results obtained by utilization of an original approach called Molecular Descriptors Family on Structure-Property (MDF-SPR) and Structure-Activity Relationships (MDF-SAR) applied on classes of chemical compounds and its usefulness as precursors of models elaboration of new compounds with better properties and/or activities and low production costs. The MDF-SPR/MDF-SAR methodology integrates the complex information obtained from compound's structure in unitary efficient models in order to explain properties/activities. The methodology has been applied on a number of thirty sets of chemical compounds. The best subsets of molecular descriptors family members able to estimate and predict property/activity of interest were identified and were statistically and visually analyzed. The MDF-SPR/MDF-SAR models were validated through internal and/or external validation methods. The estimation and prediction abilities of the MDF-SPR/MDF-SAR models were compared with previous reported models by applying of correlated correlation analysis, which revealed that the MDF-SPR/MDF-SAR methodology is reliable. The MDF-SPR/MDF-SAR methodology opens a new pathway in understanding the relationships between compound's structure and property/activity, in property/activity prediction, and in discovery, investigation and characterization of new chemical compounds, more competitive as costs and property/activity, being a method less expensive comparative with experimental methods.

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The aim of our research was to conduct a computational study on helical geometries of several homopolymers. Simple helix of polymers with seventeen (poly(lactic acid)) or eighteen (poly(1-chloro-trans-1-butenylene), poly(1-methyl-trans-1-butenylene), poly(1,4,4-trifluoro-trans-1-butenylene), polyacrylonitrile and respectively polychlorotrifluoroethylene) monomers were investigated. The X, Y, and Z coordinates obtained after optimization of the geometry of polymers were used as input data to identify the rotation and translation of the coordinates and respectively the coefficient of the helix. The values of interest were calculated by minimization of residuals using two different protocols. The first protocol investigated the whole polymer by imposing (step 1) or not (step 2) a fixed value of the helix coefficient. The second protocol investigated by minimization of residuals if the monomer (one or two) from each end of the polymer is or not an outlier of the helical geometry of the polymer.