title: Electrospray mass spectrometry in the differentiation of some isomeric trimethylfurocoumarins.
abstract: Electrospray mass spectrometry (ES-MS) was successfully employed for the structural differentiation of six isomeric trimethylfurocoumarins of possible pharmaceutical interest. Two different approaches were employed. The first was based on MS(n) experiments of MH(+) ions. Although the product ion spectra of MH(+) of the isomers are very similar, the MS(3) spectra of the collisionally generated [MH[bond]CO](+) ions show some characteristic differences. The second approach was based on complexation of the molecules with Li(+), Na(+) and K(+) using ESI-MS of sample solutions containing alkali ions in a 100:1 molar ratio with respect to the analyte. Significant differences were observed in complex production yields, and these were related to the dimension of the alkali ion and to the steric availability of chelating groups in the different isomers.
authors.affiliation: CNR, Istituto di Scienze e Tecnologie Molecolari, Corso Stati Uniti 4, I-35127 Padova, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Basso
authors.forename: Adriana
authors.initials: A
authors.lastname: Chilin
authors.forename: Adriano
authors.initials: A
authors.lastname: Guiotto
authors.forename: Pietro
authors.initials: P
authors.lastname: Traldi
mesh_terms: D011564:Furocoumarins / Q000032:analysis* / Q000737:chemistry* / Q000145:classification; D007536:Isomerism; D046911:Macromolecular Substances; D008672:Metals, Alkali / Q000032:analysis* / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D011564:Furocoumarins; D046911:Macromolecular Substances; D008672:Metals, Alkali