Synthesis of novel N-diazeniumdiolates based on hyperbranched polyethers

Novel N-diazeniumdiolate based on hyperbranched polyethers(HP-g-DACA/N2O2) were prepared through a two-step synthesized route. The alkyltrimethoxysilane containing secondary amine groups (DACA) was used to modify the hydroxyl end groups of hyperbranched polyethers (HP) to obtain the precursor hyperbranched diamine (HP-g-DACA). Then HP-g-DACA was reacted with NO at 80psi pressure to be converted into N-diazeniumdiolates. The structures were confirmed using 13C NMR and IR spectra. UV–vis spectroscopy measurement indicated that the aqueous solution of obtained HP-g-DACA/N2O2 had a characteristic absorption at 246 nm. The final HP-g-DACA/N2O2 product showed NO releasing within the prolonged periods of time, and the apparent half-life t1/2 was more than 11 min in phosphate buffer at 37 °C. The total amount of NO released from HP-g-DACA/N2O2 could achieve to 0.43 μmol/mg and was proportional to the modified degree of HP by DACA. In addition, the NO loading efficiency can be modulated by the modification degree of hyperbranched macromolecular end groups.

Synthesis scheme for preparing N-diazeniumdiolate based on hyperbranched polyether HP-g-DACA/N2O2.Figure optionsDownload as PowerPoint slide