title: New potent antioxidative hydroxyflavanones produced with Aspergillus saitoi from flavanone glycoside in citrus fruit.
abstract: Potent antioxidative hydroxyflavanones were produced with Aspergillus saitoi from hesperidin or naringin, which are flavanone glycosides in citrus fruit with weak antioxidative activity. The hydroxyflavanone produced from hesperidin was identified as 8-hydroxyhesperetin (8-HHE), a novel substance, and those from naringin were identified as carthamidin (6-hydroxynaringenin) and isocarthamidin (8-hydroxynaringenin) by FAB-MS, 1H-NMR and 13C-NMR analyses. The antioxidative activity of these hydroxyflavanones was examined by using the free radical-scavenging system of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the methyl linoleate oxidation system. The hydroxyflavanones (8-HHE, carthamidin, and isocarthamidin) exhibited stronger activity than the flavanone glycosides (hesperidin or naringin) and their aglycones (hesperetin or naringenin). The activity of 8-HHE and isocarthamidin was comparable to that of alpha-tocopherol, and that of carthamidin was weaker than that of isocarthamidin. The hydroxyflavanones, which were hydroxylated on A ring of flavanone by Aspergillus saitoi, were obtained as potent antioxidants.
authors.affiliation: Fundamental Technical Research Department of Pokka Corporation Ltd., Aichi, Japan. yoshiaki_miyake@pk.pokka.co.jp
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Miyake
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Minato
authors.forename: Syuichi
authors.initials: S
authors.lastname: Fukumoto
authors.forename: Kanefumi
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Tomoko
authors.initials: T
authors.lastname: Oya-Ito
authors.forename: Syunro
authors.initials: S
authors.lastname: Kawakishi
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Osawa
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism*; D001230:Aspergillus / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D002957:Citrus / Q000378:metabolism*; D044950:Flavanones / Q000737:chemistry / Q000378:metabolism*; D006027:Glycosides / Q000378:metabolism*; D015394:Molecular Structure
chemical_list: D000975:Antioxidants; D044950:Flavanones; D006027:Glycosides; C028610:flavanone