title: Structure and Antioxidant Activities of Proanthocyanidins from Elephant Apple (Dillenia indica Linn.).
abstract: Proanthocyanidins were isolated and purified from fruits of elephant apple (Dillenia indica Linn.) and their structural and bioactive properties were examined. Bate-Smith alcoholysis, FTIR, and (13) C NMR spectra revealed that elephant apple proanthocyanidins (EAPs) contained a dominant amount of B-type procyanidins (PC) with a minor amount of B-type prodelphinidins (PD) but no A-type interflavan linkage. (13) C NMR spectrum indicated that the cis isomer was dominant in EAPs. The electron spray ionization and matrix-assisted laser desorption ionization time of flight mass spectra of EAPs showed the clear ion peaks corresponding to B-type PC dimer to B-type PD with degree of polymerization of 11. EAPs had strong antioxidant activity, which was evidenced by the high oxygen radical scavenging capacity at 1.06 × 10(4) μmol TE/g and ferric reducing antioxidant power of 2320 μmol Fe(II)/g. The results suggest that EAPs could be extracted to be used as promising functional food materials.
  
  
  CONCLUSIONS
  In this study, the elephant apple proanthocyanidins (EAPs) with a yield of 0.23% were identified for the first time as dominant B-type poly(catechin/epicatechin) but no A-type interflavan linkage. EAPs had higher ORAC and FRAP values compared to commercial grape seed proanthocyanidins, suggesting that EAPs may be used as promising functional food materials.
authors.affiliation: Food Science and Technology Programme, Dept. of Chemistry, National Univ. of Singapore, 3 Science Drive 3, Singapore, 117543, Republic of Singapore.|College of Bioscience & Biotechnology, Fuzhou Univ, Fuzhou, 350108, China.
authors.forename: Caili
authors.initials: C
authors.lastname: Fu
authors.affiliation: Food Science and Technology Programme, Dept. of Chemistry, National Univ. of Singapore, 3 Science Drive 3, Singapore, 117543, Republic of Singapore.
authors.forename: Dongying
authors.initials: D
authors.lastname: Yang
authors.affiliation: Food Science and Technology Programme, Dept. of Chemistry, National Univ. of Singapore, 3 Science Drive 3, Singapore, 117543, Republic of Singapore.
authors.forename: Wan Yi Elaine
authors.initials: WY
authors.lastname: Peh
authors.affiliation: College of Biological Engineering, Hevnan Univ. of Technology, Zhengzhou, Henan, 450052, China.
authors.forename: Shaojuan
authors.initials: S
authors.lastname: Lai
authors.affiliation: Food Science and Technology Programme, Dept. of Chemistry, National Univ. of Singapore, 3 Science Drive 3, Singapore, 117543, Republic of Singapore.
authors.forename: Xiao
authors.initials: X
authors.lastname: Feng
authors.affiliation: Food Science and Technology Programme, Dept. of Chemistry, National Univ. of Singapore, 3 Science Drive 3, Singapore, 117543, Republic of Singapore.|National Univ. of Singapore (Suzhou) Research Inst, 377 Lin Quan Street, Suzhou Industrial Park, Suzhou, Jiangsu, 215123, China.
authors.forename: Hongshun
authors.initials: H
authors.lastname: Yang
mesh_terms: D000818:Animals; D000872:Anthocyanins / Q000032:analysis / Q000737:chemistry / Q000494:pharmacology; D000975:Antioxidants / Q000032:analysis / Q000737:chemistry / Q000494:pharmacology*; D044946:Biflavonoids / Q000032:analysis / Q000737:chemistry / Q000494:pharmacology*; D002392:Catechin / Q000032:analysis / Q000737:chemistry / Q000494:pharmacology*; D045466:Dilleniaceae / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry*; D056604:Grape Seed Extract / Q000494:pharmacology; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D044945:Proanthocyanidins / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000872:Anthocyanins; D000975:Antioxidants; D044946:Biflavonoids; D056604:Grape Seed Extract; C511402:Grape Seed Proanthocyanidins; D010936:Plant Extracts; D044945:Proanthocyanidins; C479578:procyanidin B; D002392:Catechin
keywords: Dillenia indica Linn; elephant apple; ferric-ion reducing antioxidant power; oxygen radical absorbance capacity; proanthocyanidins