Giacomo Russo
University of Naples Federico II, Italy
Title: Prediction and mechanism elucidation of analyte retention on phospholipid stationary phases (IAM-HPLC) by in silico calculated physico-chemical descriptors.
Biography
Biography: Giacomo Russo
Abstract
The present study proposes a method for an in silico calculation of phospholipophilicity. Phospholipophilicity is intended
as the measure of analyte affi nity for phospholipids; it is currently assessed by HPLC measures of analyte retention on
phosphatidylcholine-like stationary phases (IAM-Immobilized Artifi cial Membrane) resulting in log kWIAM values. Due to
the amphipathic and electrically charged nature of phospholipids, retention on these stationary phases results from complex
mechanisms, being aff ected not only by lipophilicity (as measured by n-octanol/aqueous phase partition coeffi cients, log P) but
also by the occurrence of polar and/or electrostatic intermolecular interaction forces. Diff erently from log P, to date no method
has been proposed for in silico calculation of log kWIAM. Th e study is aimed both at shedding new light into the retention
mechanism on IAM stationary phases and at off ering a high-throughput method to achieve such values. A wide set of physicochemical
and topological properties were taken into account, yielding a robust fi nal model including four in silico calculated
parameters (lipophilicity, hydrophilic/lipophilic balance, molecular size, and molecule fl exibility). Th e presented model was
based on the analysis of 205 experimentally determined values, taken from the literature and measured by a single research
group to minimize the inter laboratory variability; such model is able to predict phospholipophilicity values on both the two
IAM stationary phases to date marketed, i.e., IAM.PC.MG and IAM.PC.DD2, with a fairly good degree (r2=0.85) of accuracy.
Th e present work allowed the development of a free on-line service aimed at calculating log kWIAM values of any molecule
included in the PubChem database, which is freely available at http://nova.disfarm.unimi.it/logkwiam.html