BACKGROUND Glycation is an aging reaction of naturally occurring sugars with dermal proteins. Type I collagen and elastin are most affected by glycation during intrinsic chronological aging. AIM To study the in vitro and ex vivo assays in human skin cells and explants and the antiaging effects of glycylglycine oleamide (GGO). MATERIALS AND METHODS The antiglycation effect of GGO was assesse...

A comparative study of ab initio 6-31G(*) and semiempirical modified neglect of differential overlap (MNDO) bond orders and MNDO diatomic energy contributions for the description of bond strengths in neutral and protonated glycine, diglycine, triglycine, and dialanine is presented. Good correlations were found between 6-31G(*) and MNDO bond orders and between MNDO bond orders and diatomic energ...

We describe the preparation of a new substrate, N-gamma-L-glutamyl-5-aminoisophthalic acid dimethyl ester hydro-chloride, for the fluorometric determination of gamma-glutamyltransferase activity in serum by the "front-surface" technique. Details of the resulting method are provided. The final reaction mixture contains 4 mmol of the substrate per liter of tris(hydroxymethyl)aminomethane (100 mmo...

The acid-base properties of N,N9-disubstituted dithiooxamides derived from alkyl-a-aminoacids or glycylglycine were studied in aqueous solutions of pH 2.5-10.8. For each dithiooxamide, protonation constants were obtained from potentiometric data for three dilute aqueous solutions [I50.15 M (NaClO ), 37.08C] using the program HYPERQUAD, and are reported as conventional pK values. For 4 a compoun...

The starch granule-bound adenosine diphosphate glucosestarch glucosyltransferase isolated from the embryos of normal (nonwaxy) maize seeds is different from a similar preparation isolated from the endosperms. For the embryo preparation, the ratio of the activity with ADP-glucose to the activity with uridine diphosphate glucose is 15 at a low substrate concentration and 48 at a high concentratio...