https://www.selleckchem.com/Proteasome.html We tested the susceptibility of 102 proanthocyanidin (PA)-rich plant extracts to oxidation under alkaline conditions and the possibility to produce chemically modified PAs via oxidation. Both the nonoxidized and the oxidized extracts were analyzed using group-specific ultrahigh-performance liquid chromatography-diode array detection-tandem mass spectrometry (UHPLC-DAD-MS/MS) methods capable of detecting procyanidin (PC) and prodelphinidin (PD) moieties along the two-dimensional (2D) chromatographic fingerprints of plant PAs. The results indicated different reactivities for PCs and PDs. When detected by UHPLC-DAD only, most of the PC-rich samples exhibited only a subtle change in their PA content, but the UHPLC-MS/MS quantitation showed that the decrease in the PC content varied by 0-100%. The main reaction route was concluded to be intramolecular. The PD-rich and galloylated PAs showed a different pattern with high reductions in the original PA content by both ultraviolet (UV) and MS/MS quantitation, accompanied by the shifted retention times of the chromatographic PA humps. In these samples, both intra- and intermolecular reactions were indicated.Fluorinated polyurethane (FPU) with a different fluorine content was prepared using perfluoropolyether glycols, poly(propylene glycol), and isophorone diisocyanate as starting materials, and 1,4-butanediol as a chain extender. The structure and molecular weight of FPU were characterized by Fourier transform infrared spectroscopy and gel permeation chromatography. A solution of FPU in xylene and cresol was then coated on copper wires using an enameled machine to prepare enameled wires. The friction coefficient and adhesion performance of the enameled wires were tested. The friction coefficient of the as-prepared enameled wires reached 0.095, which was much lower than 0.149 of the polyurethane without fluorine. FPU-based enameled wires also showed good mechanical performances and i