Prolyl Endopeptidase-inhibiting Isoflavonoids from Puerariae Flos and Some Revision of their $^{13}C-NMR$ Assignment

갈화의 Prolyl Endopeptidase 저해 활성 Isoflavonoid 및 이들의 $^{13}C-NMR$ Assignment

  • Kim, Kyung-Bum (Department of Agricultural Chemistry, College of Agriculture, Kyungpook National University) ;
  • Kim, Sang-In (Department of Agricultural Chemistry, College of Agriculture, Kyungpook National University) ;
  • Kim, Jong-Sik (Department of Agricultural Chemistry, College of Agriculture, Kyungpook National University) ;
  • Song, Kyung-Sik (Department of Agricultural Chemistry, College of Agriculture, Kyungpook National University)
  • Published : 1999.11.30

Abstract

In order to find anti-dementia drugs from natural products, prolyl endopeptidase inhibitors were purified from Puerariae Flos by consecutive solvent partition, followed by silica gel, Sephadex LH-20, and HPLC. Four isoflavonoid inhibitors were isolated and identified as tectorigenin, genistein, 5,7-dihydroxy-4',6-dimethoxyisoflavone, and 5-hydroxy-6,7,4'-trimethoxyisoflavone by means of instrumental analyses including $^{1}H-$, $^{13}C-$, $^{2}D-NMR$ and MS and $IC_{50}$ values against PEP were 5.30 ppm$(17.7\;{\mu}M)$, 10.39 ppm$(38.5\;{\mu}M)$, 13.92 ppm$(44.3\;{\mu}M)$, and 20.61 ppm$(62.8\;{\mu}M)$, respectively. Some previous mistakes in $^{13}C-NMR$ assignment were revised by careful investigation of HMBC and HMQC data.