title: MALDI efficiency of metabolites quantitatively associated with their structural properties: a quantitative structure-property relationship (QSPR) approach.
abstract: Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) experiments require a suitable match of the matrix and target compounds to achieve a selective and sensitive analysis. However, it is still difficult to predict which metabolites are ionizable with a given matrix and which factors lead to an efficient ionization. In the present study, we extracted structural properties of metabolites that contribute to their ionization in MALDI-MS analyses exploiting our experimental data set. The MALDI-MS experiment was performed for 200 standard metabolites using 9-aminoacridine (9-AA) as the matrix. We then developed a prediction model for the ionization profiles (both the ionizability and ionization efficiency) of metabolites using a quantitative structure-property relationship (QSPR) approach. The classification model for the ionizability achieved a 91% accuracy, and the regression model for the ionization efficiency reached a rank correlation coefficient of 0.77. An analysis of the descriptors contributing to such model construction suggested that the proton affinity is a major determinant of the ionization, whereas some substructures hinder efficient ionization. This study will lead to the development of more rational and predictable MALDI-MS analyses.
authors.affiliation: Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Higashi-ku, Fukuoka, Japan.
authors.forename: Daichi
authors.initials: D
authors.lastname: Yukihira
authors.forename: Daisuke
authors.initials: D
authors.lastname: Miura
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Fujimura
authors.forename: Yoshikatsu
authors.initials: Y
authors.lastname: Umemura
authors.forename: Shinichi
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: Shinji
authors.initials: S
authors.lastname: Funatsu
authors.forename: Makoto
authors.initials: M
authors.lastname: Yamazaki
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ohta
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Inoue
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Shindo
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Wariishi
mesh_terms: D055432:Metabolomics; D009930:Organic Chemicals / Q000032:analysis* / Q000737:chemistry; D021281:Quantitative Structure-Activity Relationship; D012044:Regression Analysis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D009930:Organic Chemicals