Rapid complexing of oxoacylglycerols with amino acids peptides and aminophospholipids

The molecular species of TAG core aldehydes (aldehydes still esterified to parent molecules) were detected and quantified in dietary-quality sunflowerseed oil autoxidized for 0-18 d at 60 degrees C in the dark. The analyses were performed by reversed-phase HPLC with UV (358 nm) absorption or light scattering and electrospray ionization-MS (ESI/MS) detection following preparation of the dinitrophenylhydrazone derivatives. Aldehyde production, as estimated by UV and ESI/MS, increased gradually over the 18-d period following a rapid initial destruction of the core aldehydes accumulated during storage of the commercial oil at 10 degrees C for 3 mon. The contents of hydroperoxides and hydroperoxide core aldehyde combinations were estimated to account for about 5% of total TAG, quantified as area in the chromatographic trace, after 18 d of autoxidation as estimated by an evaporative light scattering detector (ELSD). The major species of core aldehydes were tentatively identified as 9-oxononanoyl (70%)-, 12-oxo-9,10-epoxydodecenoyl (10%)-, and 13-oxo-9,11-tridecadienoyl (5%)-containing acylglycerols, plus smaller amounts of simple and mixed chain-length dialdehydes, and hydroxy and epoxy monoaldehyde-containing acylglycerols (15% of total). Quantitatively, the core aldehydes made up 2-12 g/kg of oil by UV detection and 2-9 g/kg of oil by ESI/MS detection, whereas the hydroperoxides measured in the unreduced state by HPLC with ELSD were estimated at 200 g/kg after 18 d of autoxidation. The major hydroperoxides of sunflowerseed oil were as previously identified.

Section: Discussionmentioning

confidence: 71%

Tentative identification and quantification of TAG core aldehydes as dinitrophenylhydrazones in autoxidized sunflowerseed oil using reversed‐phase HPLC with electrospray lonization MS

Sjövall

Kuksis

Kallio

2003

“…Ravandi et al (61) showed earlier that the C 5 and C 9 core aldehydes of GroPCho readily form Schiff bases with the amino groups of amino acids, peptides, and myoglobin, as well as PtdEtn, whereas others demonstrated similar Schiff base formation with the core aldehydes derived from cholesteryl linoleate (4) and glyceryl-2-linoleate (34). More recently, Ravandi et al (40) found that glucosylated PtdEtn added to nonglycated LDL promotes the oxidation of PtdCho and cholesteryl esters and the uptake of glucosylated PtdEtn-containing LDL by macrophages.…”

Section: Discussionmentioning

confidence: 99%

“…Thus, the lipid ester core aldehydes are known to form Schiff bases with amino acids, peptides, and proteins and may not be recovered during ordinary lipid extraction (28,32,34). The core aldehydes of PtdCho have been shown to undergo aldol condensation (21) and might not be readily detected under routine LC-MS analysis.…”

Section: Discussionmentioning

confidence: 99%

“…The capillary exit voltage was set at 150 V, with an electron multiplier at 1795 V. For fragmentation the exit voltage was raised to 300 V and the sample was reinjected into the LC/ESI-MS system (pseudo-MS/MS). All the major fragment ions detected in the negative and positive ion mode can be assigned to the plausible cleavage products, including DAG and FA (34). Positive and negative ESI spectra were usually recorded in the mass range 400-1100, but lower mass ranges needed to be used for scanning for FA and nitrogenous bases.…”

mentioning

confidence: 99%

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Phospholipids and oxophospholipids in atherosclerotic plaques at different stages of plaque development

Ravandi

Babaei²,

Leung³

et al. 2004

We identified and quantified the hydroperoxides, hydroxides, epoxides, isoprostanes, and core aldehydes of the major phospholipids as the main components of the oxophospholipids (a total of 5-25 pmol/micromol phosphatidylcholine) in a comparative study of human atheroma from selected stages of lesion development. The developmental stages examined included fatty streak, fibrous plaque, necrotic core, and calcified tissue. The lipid analyses were performed by normal-phase HPLC with on-line electrospray MS using conventional total lipid extracts. There was great variability in the proportions of the various oxidation products and a lack of a general trend. Specifically, the early oxidation products (hydroperoxides and epoxides) of the glycerophosphocholines were found at the advanced stages of the plaques in nearly the same relative abundance as the more advanced oxidation products (core aldehydes and acids). The anticipated linear accumulation of the more stable oxidation products with progressive development of the atherosclerotic plaque was not apparent. It is therefore suggested that lipid infiltration and/or local peroxidation is a continuous process characterized by the formation and destruction of both early and advanced products of lipid oxidation at all times. The process of lipid deposition appears to have been subject to both enzymatic and chemical modification of the normal tissue lipids. Clearly, the appearance of new and disproportionate old lipid species excludes randomness in any accumulation of oxidized LDL lipids in atheroma.

“…Furthermore, polar glycerolipids containing an aldehyde group are likely to remain associated with cell membranes (12) and affect their structure and function, including receptor activity. Because the nonvolatile aldehydes have been shown (13,14) to react with amino compounds as readily as the volatile aldehydes and because hydroperoxides of dietary linoleic acid esters are converted to aldehydes in the stomach before being absorbed into the body (15,16), it is essential that acylglycerol core aldehydes be available for studies on the gastrointestinal fate and metabolic consequences of ingestion of the secondary products of triacylglycerol oxidation.…”

mentioning

confidence: 99%

Formation of triacylglycerol core aldehydes during rapid oxidation of corn and sunflower oils with tert‐butyl hydroperoxide/Fe²⁺

Sjövall

Kuksis

Kallio

2002

The lipid ester core aldehydes formed during a rapid oxidation (7.8 M tert-butyl hydroperoxide, 90 min at 37 degrees C) of the triacylglycerols of purified corn and sunflower oils were isolated as dinitrophenylhydrazones by preparative thin-layer chromatography and identified by reversed-phase high-performance liquid chromatography with on-line electrospray ionization mass spectrometry and by reference to standards. A total of 113 species of triacylglycerol core aldehydes were specifically identified, accounting for 32-53% of the 2,4-dinitrophenylhydrazine (DNPH)-reactive material of high molecular weight representing 25-33% of the total oxidation products. The major core aldehyde species (50-60% of total triacylglycerol core aldehydes) were the mono(9-oxo)nonanoyl- and mono(12-oxo)-9,10-epoxy dodecenoyl- or (12-oxo)-9-hydroxy-10,11-dodecenoyl-diacylglycerols. A significant proportion of the total (9-oxo)nonanoyl and epoxidized (12-oxo)-9,10-dodecenoyl core aldehydes was found in complex combinations with hydroperoxy or hydroxy fatty acyl groups (6-10% of total triacylglycerol core aldehydes). Identified were also di(9-oxo)nonanoylmonoacylglycerols (0.5% of total) and tri(9-oxo)nonanoylglycerols (trace). The identification of the oxoacylglycerols was consistent with the products anticipated from tert-butyl hydroperoxide oxidation of the major species of corn and sunflower oil triacylglycerols (mainly linoleoyl esters). However, the anticipated (13-oxo)-9,11-tridecadienoyl aldehyde-containing acylglycerols were absent because of further oxidation of the dienoic core aldehyde. A significant proportion of the unsaturated triacylglycerol core aldehydes contained tert-butyl groups linked to the unsaturated fatty chains via peroxide bridges (2-9%). The study demonstrates that rapid peroxidation with tert-butyl hydroperoxide constitutes an effective method for enriching natural oils and fats in triacylglycerol core aldehydes for biochemical and metabolic testing.