title: Zwitterionic N2O2-Type Protonated Dipyrrin Bearing a Phosphate Anionic Moiety as a pH-Responsive Fluorescence Indicator.
abstract: Zwitterionic protonated-dipyrrin 1 bearing a phosphate unit was synthesized from the N2O2-type tetradentate dipyrrin ligand. Compound 1 is in equilibrium with the deprotonated form 1' with a pKa value of 5.8. Compound 1 exhibited a pH-responsive fluorescence under physiological conditions; the fluorescence intensity increased in aqueous media as the pH increased. In living cells, 1 also exhibited emission responsive to pH. Thus, 1 should be applicable as a pH probe for detecting tumor cells.
authors.affiliation: Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Interdisciplinary Materials Science (TIMS), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571 Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Yamamura
authors.affiliation: Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Interdisciplinary Materials Science (TIMS), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571 Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takizawa
authors.affiliation: Graduate School of Pure and Applied Sciences and Tsukuba Research Center for Interdisciplinary Materials Science (TIMS), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571 Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Nabeshima
mesh_terms: D005456:Fluorescent Dyes / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008024:Ligands; D015394:Molecular Structure; D009609:Nitrous Oxide / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D011758:Pyrroles / Q000138:chemical synthesis* / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D005456:Fluorescent Dyes; D008024:Ligands; D010710:Phosphates; D011758:Pyrroles; D009609:Nitrous Oxide