title: Isolation and characterization of antimutagenic components ofGlycyrrhiza asperaagainstN-methyl-N-nitrosourea.
abstract: BACKGROUND
  A powdered ethanolic extract ofGlycyrrhiza asperaroot exhibits antimutagenic activity againstN-methyl-N-nitrosourea (MNU) based on the Ames assay withSalmonella typhimuriumTA1535. The aim of this study was to identify the antimutagenic components of the powdered ethanolic extract ofG. asperaroot.
  
  
  RESULTS
  The powdered ethanolic extract ofG. asperaroot was sequentially suspended inn-hexane, carbon tetrachloride, dichloromethane, ethyl acetate, and ethanol, and each solvent soluble fraction and the residue were assayed for antimutagenic activity against MNU inS. typhimuriumTA1535. The dichloromethane soluble fraction exhibited the highest antimutagenicity and was fractionated several times by silica gel chromatography. The fraction with the highest antimutagenic activity was further purified using HPLC, and the fractions were assayed for antimutagenicity against MNU inS. typhimuriumTA1535. Finally, five components with antimutagenic activity against MNU were identified as glyurallin A, glyasperin B, licoricidin, 1-methoxyphaseollin, and licoisoflavone B.
  
  
  CONCLUSIONS
  The five components were demonstrated to possess an antigenotoxic effect against carcinogenic MNU for the first time. It is important to prevent DNA damage byN-nitrosamines for cancer chemoprevention.
authors.affiliation: Faculty of Pharmaceutical Sciences, Tokyo University of Science, Yamazaki 2641, Noda, Chiba 278-8510 Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Inami
authors.affiliation: Faculty of Pharmaceutical Sciences, Tokyo University of Science, Yamazaki 2641, Noda, Chiba 278-8510 Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Mine
authors.affiliation: Tokiwa Phytochemical Co. Ltd, Sakura-shi, Japan.
authors.forename: Jin
authors.initials: J
authors.lastname: Tatsuzaki
authors.affiliation: Tokiwa Phytochemical Co. Ltd, Sakura-shi, Japan.
authors.forename: Chihiro
authors.initials: C
authors.lastname: Mori
authors.affiliation: Faculty of Pharmaceutical Sciences, Tokyo University of Science, Yamazaki 2641, Noda, Chiba 278-8510 Japan.
authors.forename: Masataka
authors.initials: M
authors.lastname: Mochizuki
keywords: 1-Methoxyphaseollin; Glyasperin B; Glyurallin A; Licoisoflavone B; Licoricidin