title: Isolation and identification of DPPH radical scavenging compounds in Kurosu (Japanese unpolished rice vinegar).
abstract: Dihydroferulic acid (DFA) and dihydrosinapic acid (DSA) were isolated from Kurosu (unpolished rice vinegar) as the major constituents responsible for Kurosu's radical scavenging activity. The levels of antioxidative activity of DFA and DSA in DPPH radical scavenging were higher than those of their respective structurally related compounds, ferulic acid and sinapic acid. The concentrations of DFA and DSA were low in common rice vinegar (polished rice vinegar), suggesting that Kurosu is more advantageous than rice vinegars as an antioxidative food item. As the concentrations of DFA and DSA were low in unpolished rice, too, these acids are thought to be produced in Kurosu through the process of the fermentation from ferulic acid and sinapic acid, respectively.
authors.affiliation: Research Center, Tamanoi Vinegar Co. Ltd., 100 Nishimachi, Yamatokoriyama, Nara 639-1038, Japan. research@tamanoi.co.jp
authors.forename: Yumi
authors.initials: Y
authors.lastname: Shimoji
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Tamura
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Kumiko
authors.initials: K
authors.lastname: Nanda
authors.forename: Shoko
authors.initials: S
authors.lastname: Nishidai
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Nishikawa
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Ishihara
authors.forename: Kazuo
authors.initials: K
authors.lastname: Uenakai
authors.forename: Hajime
authors.initials: H
authors.lastname: Ohigashi
mesh_terms: D019342:Acetic Acid / Q000737:chemistry*; D000975:Antioxidants / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification*; D001713:Biphenyl Compounds; D003373:Coumaric Acids / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D005285:Fermentation; D016166:Free Radical Scavengers / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification*; D005609:Free Radicals / Q000378:metabolism; D007564:Japan; D012275:Oryza / Q000737:chemistry*; D010851:Picrates / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D003373:Coumaric Acids; D016166:Free Radical Scavengers; D005609:Free Radicals; D010851:Picrates; C073734:sinapinic acid; C004999:ferulic acid; C004931:1,1-diphenyl-2-picrylhydrazyl; D019342:Acetic Acid