Journal: Frontiers in Chemistry
Article Title: A Multi-Step Chromatographic Approach to Purify Radically Generated Ferulate Oligomers Reveals Naturally Occurring 5-5/8-8(Cyclic)-, 8-8(Noncyclic)/8-O-4-, and 5-5/8-8(Noncyclic)-Coupled Dehydrotriferulic Acids
Figure Lengend Snippet: Sephadex LH-20 chromatograms of a mixture of oligoferulic acids generated by radical coupling of ethyl ferulate. Chromatographic conditions were (A) 0.5 mM aqueous trifluoroacetic acid/methanol 95/5 (v/v), flow rate: 1.5 mL/min; (B) 0.5 mM aqueous trifluoroacetic acid/methanol 50/50 (v/v), flow rate: 1.0 mL/min; (C) 0.5 mM aqueous trifluoroacetic acid/methanol 40/60 (v/v), flow rate: 1.0 mL/min. Collected fractions contained: 1, unknown; 2, 8-8(cyclic)-dehydrodiferulic acid (DFA) and trimer 1 ; 3, 8-8(noncyclic)-DFA; 4, trimer 2 ; 5, 8-8(cyclic)/5-5-dehydrotriferulic acid (TriFA); 6, monoethyl ester of trimer 3 ; 7, unknown; 8, trimer 3 ; 9, 5-5-DFA and 8-5(noncyclic)/5-5-TriFA; 10, 5-5/8-O-4-TriFA.
Article Snippet: Research chemicals were obtained from the following suppliers: Cu(I)Cl, copper(II)-tetramethylethylenediamine (TMEDA), HCl (37%), NaOH, ammonium chloride, ethyl acetate, and ethanol from Carl Roth GmbH (Karlsruhe, Germany); acetonitrile, diethyl ether, methanol, acetone, petroleum ether, tetrahydrofuran, and Na2 SO4 from VWR International (Radnor, PA, USA); acetone- d 6 , ferulic acid, [1-13 C]triethyl phosphonoacetate, and trifluoroacetic acid from Sigma-Aldrich (St. Louis, MO, USA); D2 O from deutero GmbH (Kastellaun, Germany); acetyl chloride and vanillin from Fluka (Buchs, Switzerland); formic acid from Merck KGaA (Darmstadt, Germany); NaHCO3 from Riedel-de Haën AG (Seelze, Germany); carbogen (5% CO2 ) from Air Liquide S.A. (Düsseldorf, Germany), and NaH (60% dispersion in oil) from Alfa Aesar (Karlsruhe, Germany).
Techniques: Generated, Flow Cytometry, Direct Fluorescent Antibody Test