title: 4-Hydroxy-2-nonenal (4-HNE) and Its Lipation Product 2-Pentylpyrrole Lysine (2-PPL) in Peanuts.
abstract: After synthesis of a deuterated 4-hydroxy-2-nonenal (4-HNE) standard, the formation of 4-HNE during heating of peanut oil and whole peanuts, respectively, was measured by GC-MS. Whereas a significant increase in 4-HNE levels was observed for peanut oil, the amount of 4-HNE decreased when whole peanuts were roasted due to lipation reactions with amino acid side chains of the proteins. The ε-amino group of lysine was identified as the favored reaction partner of 4-HNE. After heating N(α)-acetyl-l-lysine and 4-HNE, a Schiff base, a novel pyridinium derivative, a 2-pentylpyrrol derivative and, following reduction and hydrolysis, a reduced, cyclized Michael adduct were identified. 2-Amino-6-(2-pentyl-1H-pyrrol-1-yl)hexanoic acid (2-PPL) was synthesized and quantitated in peanut proteins, which had been incubated with various amounts of 4-HNE by HPLC-ESI-MS/MS after enzymatic hydrolysis. At low 4-HNE concentrations the modification of lysine could be entirely explained by the formation of 2-PPL. Additionally, 2-PPL was quantified for the first time in peanut samples, and an increase depending on the roasting time was observed. 2-PPL represents a suitable marker to evaluate the extent of food protein lipation by 4-HNE.
authors.affiliation: Institute of Food Chemistry, Technische Universität Dresden, D-01062 Dresden, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Globisch
authors.affiliation: Institute of Food Chemistry, Technische Universität Dresden, D-01062 Dresden, Germany.
authors.forename: Diana
authors.initials: D
authors.lastname: Kaden
authors.affiliation: Institute of Food Chemistry, Technische Universität Dresden, D-01062 Dresden, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Henle
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D010367:Arachis / Q000737:chemistry*; D003296:Cooking; D006358:Hot Temperature; D008055:Lipids / Q000737:chemistry*; D008239:Lysine / Q000737:chemistry*; D015394:Molecular Structure; D000074241:Peanut Oil; D010938:Plant Oils / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*
chemical_list: D000447:Aldehydes; D008055:Lipids; D000074241:Peanut Oil; D010938:Plant Oils; D011758:Pyrroles; C027576:4-hydroxy-2-nonenal; D008239:Lysine
keywords: 2-PPL; 2-pentylpyrrole; 2-pentylpyrrole lysine; 4-HNE; 4-hydroxy-2-nonenal; 4-hydroxynon-2-enal; 4-hydroxynonenal; HNE; carbonyl protein reaction; lipation; lipid peroxidation; peanut; peanut oil