title: Raman database of amino acids solutions: a critical study of extended multiplicative signal correction.
abstract: The Raman spectra of biological materials always exhibit complex profiles, constituting several peaks and/or bands which arise due to the large variety of biomolecules. The extraction of quantitative information from these spectra is not a trivial task. While qualitative information can be retrieved from the changes in peaks frequencies or from the appearance/disappearance of some peaks, quantitative analysis requires an examination of peak intensities. Unfortunately in biological samples it is not easy to identify a reference peak for normalizing intensities, and this makes it very difficult to study the peak intensities. In the last decades a more refined mathematical tool, the extended multiplicative signal correction (EMSC), has been proposed for treating infrared spectra, which is also capable of providing quantitative information. From the mathematical and physical point of view, EMSC can also be applied to Raman spectra, as recently proposed. In this work the reliability of the EMSC procedure is tested by application to a well defined biological system: the 20 standard amino acids and their combination in peptides. The first step is the collection of a Raman database of these 20 amino acids, and subsequently EMSC processing is applied to retrieve quantitative information from amino acids mixtures and peptides. A critical review of the results is presented, showing that EMSC has to be carefully handled for complex biological systems.
authors.affiliation: BioNEM Laboratory, Experimental and Clinical Medicine Department, University "Magna Graecia" of Catanzaro, 88100 Loc. Germaneto, Catanzaro, Italy. patrizio.candeloro@unicz.it.
authors.forename: Patrizio
authors.initials: P
authors.lastname: Candeloro
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Grande
authors.forename: Raffaella
authors.initials: R
authors.lastname: Raimondo
authors.forename: Daniele
authors.initials: D
authors.lastname: Di Mascolo
authors.forename: Francesco
authors.initials: F
authors.lastname: Gentile
authors.forename: Maria Laura
authors.initials: ML
authors.lastname: Coluccio
authors.forename: Gerardo
authors.initials: G
authors.lastname: Perozziello
authors.forename: Natalia
authors.initials: N
authors.lastname: Malara
authors.forename: Marco
authors.initials: M
authors.lastname: Francardi
authors.forename: Enzo
authors.initials: E
authors.lastname: Di Fabrizio
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D003628:Database Management Systems; D012996:Solutions; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D000596:Amino Acids; D012996:Solutions