et al. / A novel water-soluble fluorescent probe Mass spectrometry. (5-I3C)-Retinal: m/z 285 (M + ); I3C incorporation calcd. from the mass spectra: 85%; exact mass calcd. for '3C,,'3CH,,0: 258.2174; found: 285.2164. ( 18-'3C)-Retinal: m/z 285 ( M + ) ; I3C incorporation calcd. from the mass spectra: 92.4%.from the Netherlands Organization for the Advancement of Pure Research (ZWO). The authors wich to hank Drs. C. Erkelens and Mr. F. Lefeber for recording the NMR spectra and Mr. J . J. van Houte for recording the mass spectra. The manuscript was reviewed by Miss S. Amadio.Abstract. The reaction of the 3,3',5,5'-tetramethyI-2,2'-pyrromethen-1,l '-BF, complex with chlorosulfonic acid and its subsequent neutralisation with sodium bicarbonate yields the titled compound 1, which, in addition to appropriate thermal and photochemical stability, possesses excellent fluorescent properties. As a preliminary assay of its potential usefulness as a fluorescent probe in medical and biological research, the chemical was administered intravenously to rats and possible signs of toxicity were recorded. The rats showed no apparent detrimental effects and excreted the compound in the urine within three hours. In tests in which Salmonella and E. coli strains were used as indicators of genotoxicity, no mutagenic effects were observed.

Der nach bekannten Verfahren hergestellte Komplex (I) ergibt nach Reaktion mit l mol Chlorsulfonsäure (II) und nachfolgender Neutralisierung mit Nal‐ICO; die orangebraune Titelverbindung (III).