title: Quantitative structure-property relationship analysis for the retention index of fragrance-like compounds on a polar stationary phase.
abstract: A quantitative structure-property relationship (QSPR) was developed for modeling the retention index of 1184 flavor and fragrance compounds measured using a Carbowax 20M glass capillary gas chromatography column. The 4885 molecular descriptors were calculated using Dragon software, and then were simultaneously analyzed through multivariable linear regression analysis using the replacement method (RM) variable subset selection technique. We proceeded in three steps, the first one by considering all descriptor blocks, the second one by excluding conformational descriptor blocks, and the last one by analyzing only 3D-descriptor families. The models were validated through an external test set of compounds. Cross-validation methods such as leave-one-out and leave-many-out were applied, together with Y-randomization and applicability domain analysis. The developed model was used to estimate the I of a set of 22 molecules. The results clearly suggest that 3D-descriptors do not offer relevant information for modeling the retention index, while a topological index such as the Randić-like index from reciprocal squared distance matrix has a high relevance for this purpose.
authors.affiliation: Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas INIFTA (CCT La Plata-CONICET, UNLP), Diag. 113 y 64, C.C. 16, Sucursal 4, 1900 La Plata, Argentina; Decanato General de Investigaciones, Universidad del Azuay, Av. 24 de Mayo 7-77 y Hernán Malo, Apartado Postal 01.01.981, Cuenca, Ecuador. Electronic address: crojasvilla@gmail.com.
authors.forename: Cristian
authors.initials: C
authors.lastname: Rojas
authors.affiliation: Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas INIFTA (CCT La Plata-CONICET, UNLP), Diag. 113 y 64, C.C. 16, Sucursal 4, 1900 La Plata, Argentina.
authors.forename: Pablo R
authors.initials: PR
authors.lastname: Duchowicz
authors.affiliation: Laboratorio de Química-Física de Alimentos, Facultad de Ciencia y Tecnología, Universidad del Azuay, Av. 24 de Mayo 7-77 y Hernán Malo, Apartado Postal 01.01.981, Cuenca, Ecuador.
authors.forename: Piercosimo
authors.initials: P
authors.lastname: Tripaldi
authors.affiliation: CEQUINOR, Centro de Química Inorgánica (CONICET, UNLP), Departamento de Química, Facultad de Ciencias Exactas, UNLP, C.C. 962, 1900 La Plata, Argentina.
authors.forename: Reinaldo
authors.initials: R
authors.lastname: Pis Diez
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002849:Chromatography, Gas; D005421:Flavoring Agents / Q000737:chemistry*; D016014:Linear Models; D008962:Models, Theoretical; D008968:Molecular Conformation; D010476:Perfume / Q000737:chemistry*; D021281:Quantitative Structure-Activity Relationship; D015203:Reproducibility of Results; D012984:Software
chemical_list: D005421:Flavoring Agents; D010476:Perfume
keywords: Carbowax 20M column; Dragon software; Fragrance; QSPR theory; Replacement method; k-Means cluster analysis