Part I: Toward characterization of the fluorescent aging pigment. Part II: Structural studies of glycans at microscale

art I. Previous observations that the aging process correlates with occurrence of certain fluorescent biological pigments have led to numerous efforts in elucidating the chemical nature of the fluorophores. In this study, model reactions of saturated aldehydes with aliphatic amines in the presence of peroxides were found to generate such characteristic fluorescence. The fluorescent compounds have been chromatographically isolated and their structures determined, through various spectroscopic techniques, to be alkylated 2-hydroxy-1,2-dihydropyrrol-3-ones. The finding of such fluorescent structures led to the development of 2-methyl-3-oxo-4-phenyl-2,3-dihydrofuran-2-yl acetate (PDFAc) as a new fluorogenic reagent for primary amine derivatization. PDFAc reacts with primary amines, such as peptides and aminated carbohydrates, giving fluorescent 2-hydroxy-1,2-dihydropyrrol-3-ones (pyrrolinones). The fluorescent derivatives have good stability in both acidic and basic solutions.;Part II. A solid-phase...