title: Caffeic acid derivatives in the roots of yacon (Smallanthus sonchifolius).
abstract: Five caffeic acid derivatives were found in the roots of yacon, Smallanthus sonchifolius (Poepp. and Endl.) H. Robinson, Asteraceae, as the major water-soluble phenolic compounds. The structures of these compounds were determined by analysis of spectroscopic data. Two of these were chlorogenic acid (3-caffeoylquinic acid) and 3,5-dicaffeoylquinic acid, common phenolic compounds in plants of the family Asteraceae. Three were esters of caffeic acid with the hydroxy groups of aldaric acid, derived from hexose. The structure of the aldaric moiety was determined by hydrolysis and comparison of NMR spectra with those of standard aldaric acids. The compounds were novel caffeic acid esters of altraric acid: 2,4- or 3,5-dicaffeoylaltraric acid, 2,5-dicaffeoylaltraric acid, and 2,3,5- or 2,4,5-tricaffeoylaltraric acid.
authors.affiliation: National Food Research Institute, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan. tknk1221@nfri.affrc.go.jp
authors.forename: Makiko
authors.initials: M
authors.lastname: Takenaka
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Yan
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ono
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Yoshida
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Nagata
authors.forename: Tateo
authors.initials: T
authors.lastname: Nakanishi
mesh_terms: D019659:Asteraceae / Q000737:chemistry*; D002109:Caffeic Acids / Q000032:analysis* / Q000737:chemistry; D002726:Chlorogenic Acid / Q000031:analogs & derivatives* / Q000032:analysis; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D018517:Plant Roots / Q000737:chemistry*
chemical_list: D002109:Caffeic Acids; D002726:Chlorogenic Acid; C100434:3,5-dicaffeoylquinic acid