title: A study of the relationship between the chemical structures and the fluorescence quantum yields of coumarins, quinoxalinones and benzoxazinones for the development of sensitive fluorescent derivatization reagents.
abstract: To develop new fluorescent derivatization reagents, we investigated the relationship between the chemical structures and the fluorescence quantum yields (phi(f)) of coumarins, quinoxalinones and benzoxadinones. Forty-six compounds were synthesized and their fluorescence spectra were measured in n-hexane, ethyl acetate, methanol and water. The energy levels of these compounds were calculated by combination of the semi-empirical AM1 and INDO/S (CI = all) methods. The deltaE(Tn(n,pi*), S1(pi,pi*)) (the energy gap between the Tn(n,pi*) and S1(pi,pi*) states) values were well correlated with the phi(f) values, which enables us to predict the phi(f) values from their chemical structures. Based on this relationship, 3-phenyl-7-N-piperazinoquinoxalin-2(1H)-one (PQ-Pz) and 7-(3-(S)-aminopyrrolidin-1-yl)-3-phenylquinoxalin-2-(1H)-one (PQ-APy) were developed as fluorescent derivatization reagents for carboxylic acids. The derivatives of the carboxylic acids with PQ-Pz and PQ-APy showed large phi(f) values even in polar solvents, suggesting that these reagents are suitable for the microanalysis of biologically important carboxylic acids by reversed phase HPLC.
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Azuma
authors.forename: Sachiko
authors.initials: S
authors.lastname: Suzuki
authors.forename: Seiichi
authors.initials: S
authors.lastname: Uchiyama
authors.forename: Toshi
authors.initials: T
authors.lastname: Kajiro
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Santa
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Imai
mesh_terms: D001583:Benzoxazoles / Q000737:chemistry*; D003374:Coumarins / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D011810:Quinoxalines / Q000737:chemistry*; D013057:Spectrum Analysis
chemical_list: D001583:Benzoxazoles; D003374:Coumarins; D005456:Fluorescent Dyes; D011810:Quinoxalines