title: Hydroxycinnamoylmalic acids and their methyl esters from pear (Pyrus pyrifolia Nakai) fruit peel.
abstract: Two novel caffeoylmalic acid methyl esters, 2-O-(trans-caffeoyl)malic acid 1-methyl ester (6) and 2-O-(trans-caffeoyl)malic acid 4-methyl ester (7), were isolated from pear (Pyrus pyrifolia Nakai cv. Chuhwangbae) fruit peels. In addition, 5 known hydroxycinnamoylmalic acids and their methyl esters were identified: 2-O-(trans-coumaroyl)malic acid (1), 2-O-(cis-coumaroyl)malic acid (2), 2-O-(cis-coumaroyl)malic acid 1-methyl ester (3), 2-O-(trans-coumaroyl)malic acid 1-methyl ester (4), and 2-O-(trans-caffeoyl)malic acid (phaselic acid, 5). The chemical structures of these compounds were determined by spectroscopic data from ESI MS and NMR. Of all the isolated compounds, five hydroxycinnamoylmalic acids and their methyl esters (2-4, 6, 7) were identified in the pear for the first time.
authors.affiliation: Department of Food Science and Technology and Functional Food Research Center, Chonnam National University, Gwangju 500-757, Republic of Korea.
authors.forename: Ki Hoon
authors.initials: KH
authors.lastname: Lee
authors.forename: Jeong-Yong
authors.initials: JY
authors.lastname: Cho
authors.forename: Hyoung Jae
authors.initials: HJ
authors.lastname: Lee
authors.forename: Young-Kyu
authors.initials: YK
authors.lastname: Ma
authors.forename: Joseph
authors.initials: J
authors.lastname: Kwon
authors.forename: Seong Hwa
authors.initials: SH
authors.lastname: Park
authors.forename: Sang-Hyun
authors.initials: SH
authors.lastname: Lee
authors.forename: Jeong An
authors.initials: JA
authors.lastname: Cho
authors.forename: Wol-Soo
authors.initials: WS
authors.lastname: Kim
authors.forename: Keun-Hyung
authors.initials: KH
authors.lastname: Park
authors.forename: Jae-Hak
authors.initials: JH
authors.lastname: Moon
mesh_terms: D002109:Caffeic Acids / Q000737:chemistry / Q000302:isolation & purification; D003373:Coumaric Acids / Q000737:chemistry / Q000302:isolation & purification*; D004952:Esters / Q000302:isolation & purification; D005638:Fruit / Q000737:chemistry*; D008293:Malates / Q000737:chemistry / Q000302:isolation & purification*; D015394:Molecular Structure; D031989:Pyrus / Q000737:chemistry*
chemical_list: D002109:Caffeic Acids; D003373:Coumaric Acids; D004952:Esters; D008293:Malates; C099798:caffeoylmalic acid