Quantitative Structure–Retention Relationship (QSRR) Study for Predicting Gas Chromatographic Retention Times for Some Stationary Phases

Abstract

A QSPR study was realized in order to predict the Retention Times (RT) determined from interaction between two types of solutes (alcohols and esters) and six Stationary Phases (SPs), five of them specials (1a -e) and a classical one (OV-25), by correlating the adjusted RTs, t 0 R determined for each SPs at temperature between 70 and 140 8C with the values of molecular descriptors implemented in CODESSA program. New topological indices R AF (for alcohols) and D A (for esters) derived from local invariants of chemical graphs of alcohols and esters determine an increase in predictive power of models where these descriptors have been used.

Screening, Synthesis, and QSAR Research on Cinnamaldehyde-Amino Acid Schiff Base Compounds as Antibacterial Agents

“…The second descriptor was the WNSA-1 weighted PNSA (D 6 ). WNSA-1 is a quantum-chemical descriptor, which characterizes molecules by molecular shape and electron distribution and is defined in Equation (4): where PNSA1 is the partial negatively charged molecular surface area and the TMSA is the total molecular surface area [ 27 ]. This descriptor was defined based on the total molecular surface area and charge distribution in the molecule.…”

“…This descriptor was defined based on the total molecular surface area and charge distribution in the molecule. It indicated the influence of charge distribution on antibacterial activity [ 27 ]. According to the optimal model, an increase in WNSA-1 led to a decrease in the antibacterial activity of cinnamaldehyde compounds.…”

Quantitative Structure Activity Relationship of Cinnamaldehyde Compounds against Wood-Decaying Fungi

“…The second descriptor was FNSA-3 fractional PNSA (PNSA-3/TMSA), d2 [18], which is the ratio of PNSA-3 and TMSA that can be computed as follows [19]: FNSA−3=PNSA−3/TMSA where TMSA is total area of the molecule and PNSA-3 is the atomic charge weight of the negatively charged molecular surface area [20]: PNSA−3=140%true∑​qASA normalA∈{δA<0} where q A is the partial charge of the atom and S A is the respective atomic negatively charged solvent-accessible surface area. Both q A and S A were computed in Codessa.…”

“…The third descriptor was ESP-RPCS relative charged SA (SAMPOS*RPCG) (Quantum-Chemical PC), d3, which is also a quantum chemical descriptor. This descriptor reflects the total molecular surface area and properties of the function group and indicates interactions among polar molecules [18].…”

Topological Indexes and QSRR Methodology in Pharmaceutical and Chemical Analysis

“…Xia et al (105) used different classes of structural descriptors, namely, valence and nonvalence molecular connectivity, geometrical descriptors, electrostatic descriptors, and quantum chemical descriptors. After calculating a large number of descriptors, the heuristic method in the computer software CODESSA was used to select the suitable descriptor combinations to build the linear QSRR models of illicit drugs investigated by GC/MS (105), 209 polybrominated diphenyl ether congeners (106), polychlorinated biphenyl congeners (107,108), and alcohols and esters (109). Liu et al (110) used the molecular electronegativity distance vector descriptors derived directly from the molecular topological structures to predict the GC relative retention times of 209 polychlorinated biphenyls on SE-54 stationary phase.…”