<i>N</i>¹, <i>N</i>¹⁴-diferuloylspermine as an antioxidative phytochemical contained in leaves of <i>Cardamine fauriei</i>

<p>Most Brassicaceae vegetables are ideal dietary sources of antioxidants beneficial for human health. <i>Cardamine fauriei</i> (Ezo-wasabi in Japanese) is a wild, edible Brassicaceae herb native to Hokkaido, Japan. To clarify the main antioxidative phytochemical, an 80% methanol extraction from the leaves was fractionated with Diaion® HP-20, Sephadex® LH-20, and Sep-Pak® C18 cartridges, and the fraction with strong antioxidant activity depending on DPPH method was purified by HPLC. Based on the analyses using HRESIMS and MS/MS, the compound might be <i>N</i>¹, <i>N</i>¹⁴-diferuloylspermine. This rare phenol compound was chemically synthesized, whose data on HPLC, MS and ¹H NMR were compared with those of naturally derived compound from <i>C. fauriei</i>. All results indicated they were the same compound. The radical-scavenging properties of diferuloylspermine were evaluated by ORAC and ESR spin trapping methods, with the diferuloylspermine showing high scavenging activities of the ROO^·, O₂^·−, and HO^· radicals as was those of conventional antioxidants.</p