Willy Leimgruber

Fluorescamine: A Reagent for Assay of Amino Acids, Peptides, Proteins, and Primary Amines in the Picomole Range

Fluorescamine is a new reagent for the detection of primary amines in the picomole range. Its reaction with amines is almost instantaneous at room temperature in aqueous media. The products are highly fluorescent, whereas the reagent and its degradation products are nonfluorescent. Applications are discussed.

Studies on the reaction of fluorescamine with primary amines

Abstract Fluorescamine is a useful reagent for the fluorometric assay of primary amines. The extent of the reaction between fluorescamine and primary amines, as well as the fluorescence intensities of the resulting fluorophors depend on pH, solvent composition and reagent concentration. Optimum values for these variables further depend on the amine under study. The influence of these parameters on the fluorogenic reaction of representative amines, and on their fluorophoric derivatives has been investigated, and the results are reported here.

Fluorometric assay of secondary amino acids

Abstract A method is described for the conversion of secondary amino acids to primary amines which can be assayed with fluorescamine (I). Secondary amino acids undergo oxidative decar☐ylation when reacted with halogenating agents. The resulting imines are hydrolyzed to primary amines, which are subsequently allowed to react with fluorescamine (I) to yield fluorescent pyrrolinones (II). This reaction sequence provides an efficient fluorometric assay for secondary amino acids. Thus, the fluorescamine procedure is now applicable to the full array of natural amino acids.

Fluorescent labeling of proteins. A new methodology.

Abstract A new reagent, 2-methoxy-2,4-diphenyl-3(2 H )-furanone (MDPF) has been utilized for the fluorescent labeling of proteins. MDPF, which is nonfluorescent, reacts with primary amino groups to form fluorescent N -substituted 3,5-diphenyl-5-hydroxy-2-pyrrolin-4-ones. Antibodies labeled with MDPF afford intense immunofluorescent staining.

Fluorometric reagents for primary amines. Syntheses of 2-alkoxy- and 2-acyloxy-3(2H)-furanones

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Stability determining factors in anomeric coumerosides

Abstract The thermodynamic equilibrium between the anomeric coumerosides 3 and 4 differs drastically from that which exists between their C(2)-epimers 7 and 8 . Stability determining factors which govern the position of these equilibria include in addition to steric interactions the Δ2 effect and the anomeric effect. The latter is discussed in terms of orbital overlap between nonbonding electrons on oxygen and anti -bonding σ orbitals. The α-configuration of the glycoside linkages of coumermycin A 1 was secured by X-ray analysis of compound 12 .