title: Identification and characterization of a novel fermented substance produced by edible Aspergillus oryzae AO-1 that inhibits DPP-IV activity.
abstract: We identified a novel fermented substance (FKA) produced by the edible Aspergillus oryzae strain AO-1 that inhibited dipeptidyl peptidase IV (DPP-IV) (IC(50) = 3.41 mg · mL(-1)). HPLC analysis of FKA showed specific one metabolite (WYK-1), which inhibited DPP-IV (IC(50) = 6.98 μM). WYK-1 was identified as a tetrahydroxyisoquinoline derivative. Interestingly, we examined 60 strains of A. oryzae, AO-1 was the only A. oryzae strain that produces WYK-1. This is the first report that an edible A. oryzae strain produces a DPP-IV inhibitor such as WYK-1. This study also suggests that FKA has applications in the development of novel antihyperglycemic therapeutics or functional foods.
authors.affiliation: Healthcare Research Institute, Wakunaga Pharmaceutical Co, Ltd, 1624 Shimokotachi, Koda-cho, Akitakata-shi, Hiroshima 739-1195, Japan. imamura_kz@wakunaga.co.jp
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Imamura
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Tsuyama
authors.forename: Terukage
authors.initials: T
authors.lastname: Hirata
mesh_terms: D001236:Aspergillus oryzae / Q000235:genetics / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D054873:Dipeptidyl-Peptidase IV Inhibitors / Q000378:metabolism*; D005285:Fermentation; D010802:Phylogeny; D044005:Tetrahydroisoquinolines / Q000378:metabolism*
chemical_list: D054873:Dipeptidyl-Peptidase IV Inhibitors; D044005:Tetrahydroisoquinolines