title: Trimeric and Tetrameric A-Type Procyanidins from Peanut Skins.
abstract: Peanut skins are a rich source of oligomeric and polymeric procyanidins. The oligomeric fractions are dominated by dimers, trimers, and tetramers. A multistep chromatographic fractionation led to the isolation of four new A-type procyanidins of tri- and tetrameric structures. The structures of the new trimers were defined by NMR, electronic circular dichroism, and MS data as epicatechin-(4β→8,2β→O→7)-epicatechin-(4β→8,2β→O→7)-catechin, peanut procyanidin B (3), and epicatechin-(4β→8,2β→O→7)-epicatechin-(4β→6)-catechin, peanut procyanidin C (4). The new tetramers were defined as epicatechin-(4β→8,2β→O→7)-epicatechin-(4β→6)-epicatechin-(4β→8,2β→O→7)-catechin, peanut procyanidin E (1), and epicatechin-(4β→8,2β→O→7)-epicatechin-(4β→6)-epicatechin-(4β→8,2β→O→7)-epicatechin, peanut procyanidin F (2). In addition, both A-type dimers A1, epicatechin-(4β→8,2β→O→7)-catechin, and A2, epicatechin-(4β→8,2β→O→7)-epicatechin, as well as two known peanut trimers, ent-epicatechin-(4β→6)-epicatechin-(4β→8,2β→O→7)-catechin, peanut procyanidin A (5), and epicatechin-(4β→8)-epicatechin-(4β→8,2β→O→7)-catechin, peanut procyanidin D (6), were also isolated. Dimer A1, the four trimers, and two tetramers were evaluated for anti-inflammatory activity in an in vitro assay, in which LPS-stimulated macrophages were responding with secretion of TNF-α, a pro-inflammatory cytokine. Tetramer F (2) was the most potent, suppressing TNF-α secretion to 82% at 8.7 μM (10 μg/mL), while tetramer E (1) at the same concentrations caused a 4% suppression. The results of the TNF-α secretion inhibition indicate that small structural differences, as in peanut procyanidin tetramers E and F, can be strongly differentiated in biological systems.
authors.affiliation: Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences , Sienkiewicza 112, 90-363 Lodz, Poland.|Physical Chemistry Department, Medical University of Warsaw , Banacha 1, 02-097 Warsaw, Poland.
authors.forename: Marta K
authors.identifier: 0000-0003-3412-0177
authors.initials: MK
authors.lastname: Dudek
authors.affiliation: Planta Analytica LCC , 461 Danbury Road, New Milford, Connecticut 06776, United States.
authors.forename: Vitold B
authors.initials: VB
authors.lastname: Gliński
authors.affiliation: Planta Analytica LCC , 461 Danbury Road, New Milford, Connecticut 06776, United States.
authors.forename: Matthew H
authors.initials: MH
authors.lastname: Davey
authors.affiliation: DSTest-Laboratories LLC , Purdue Research Park, 5225 Exploration Drive, Indianapolis, Indiana 46241, United States.
authors.forename: Daniel
authors.initials: D
authors.lastname: Sliva
authors.affiliation: Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences , Sienkiewicza 112, 90-363 Lodz, Poland.
authors.forename: Sławomir
authors.initials: S
authors.lastname: Kaźmierski
authors.affiliation: Planta Analytica LCC , 461 Danbury Road, New Milford, Connecticut 06776, United States.
authors.forename: Jan A
authors.initials: JA
authors.lastname: Gliński
mesh_terms: D010367:Arachis / Q000737:chemistry*; D044946:Biflavonoids / Q000737:chemistry* / Q000302:isolation & purification*; D002392:Catechin / Q000737:chemistry* / Q000302:isolation & purification*; D004305:Dose-Response Relationship, Drug; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D044945:Proanthocyanidins / Q000737:chemistry* / Q000302:isolation & purification*; D014409:Tumor Necrosis Factor-alpha / Q000187:drug effects
chemical_list: D044946:Biflavonoids; D044945:Proanthocyanidins; D014409:Tumor Necrosis Factor-alpha; C479581:procyanidin B3; C479583:procyanidin C; C017674:procyanidin; D002392:Catechin