title: Chemical synthesis, redox transformation, and identification of sonnerphenolic C, an antioxidant in Acer nikoense.
abstract: Sonnerphenolic C (3), which was predicted in a redox product of epirhododendrin (1) isolated from Acer nikoense, was synthesized for the first time via the epimeric separation of benzylidene acetal intermediates as a key step. From a similar synthetic route, 1 was obtained concisely. As a result of their antioxidative evaluation, only 3 revealed potent activity. The redox transformation of 1 into 3 was achieved in the presence of tyrosinase and vitamin C. Moreover, 3 was identified in the decoction of A. nikoense by HPLC analysis with the effective use of synthesized 3. Thus, a novel naturally occurring antioxidant 3 was developed through the sequential flow including redox prediction, chemical synthesis, evaluation of the activity, and identification as the natural product.
authors.affiliation: Department of Applied Life Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Iwadate
authors.affiliation: Department of Applied Life Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan; Department of Applied Biological Chemistry, Faculty of Agriculture, Utsunomiya University, Tochigi 321-0943, Japan. Electronic address: nihei98@cc.utsunomiya-u.ac.jp.
authors.forename: Ken-Ichi
authors.initials: KI
authors.lastname: Nihei
mesh_terms: D031002:Acer / Q000737:chemistry*; D000975:Antioxidants / Q000138:chemical synthesis* / Q000302:isolation & purification / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology; D001713:Biphenyl Compounds / Q000737:chemistry; D002396:Catechols / Q000138:chemical synthesis* / Q000302:isolation & purification / Q000494:pharmacology*; D005960:Glucosides / Q000138:chemical synthesis* / Q000302:isolation & purification / Q000494:pharmacology*; D010084:Oxidation-Reduction; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D002396:Catechols; D005960:Glucosides; D010851:Picrates; D010936:Plant Extracts; C000621238:sonnerphenolic C; C004931:1,1-diphenyl-2-picrylhydrazyl; D001205:Ascorbic Acid
keywords: Antioxidant; Epirhododendrin; Redox transformation; Sonnerphenolic C