Interannual variations in the lipids of the Antarctic pteropods Clione limacina and Clio pyramidata

Antarctic pteropods, Clione limacina (Order Gymnosomata) and Clio pyramidata (order Thecosomata), were collected near Elephant Island, South Shetland Islands, during 1997 and 1998. Total lipid was high in C. limacina (29--36 mg g(-1) wet mass) and included 46% of diacy1glyceryl ether (DAGE, as % of total lipid) for both 1997 and 1998. DAGE was not detected in C. pyramidata, which had mainly polar lipid and triacy1glycerol. 1-O-Alkyl glyceryl ethers (GE) derived from the DAGE consisted primarily of 15:0 and 16:0, with lower 17:0 and a17:0. The principal sterols of both pteropods included trans-dehydrocholesterol, brassicasterol, 24-methylenecholesterol, cholesterol and desmosterol. Levels of 24-methylenecholesterol and desmosterol were lower in both pteropods in 1997 compared to 1998. C. limacina had high levels of the odd-chain fatty acids 17:1(n--8)c and 15:0 in contrast to C. pyramidata. The previously proposed source of elevated odd-chain fatty acids in C. limacina is via propionate derived from phytoplankton DMPT; another possible source may be from thraustochytrids, which are common marine microheterotrophs. C. pyramidata had twice as much PUFA as C. limacina, largely due to higher 20:5(n--3). The PUFA 18:5(n--3) and very long chain fatty acids (C(24), C(26) and C(28) VLC-PUFA) were only detected in 1998 pteropods. In comparison, 1996 samples of C. limacina contained lower DAGE levels, which also may reflect differences in diet and oceanographic conditions. Interannual variations in specific lipid biomarkers are discussed with respect to possible different phytoplankton food sources available in the AMLR survey area.     

Interrelationships among the ethanolamine phosphatides in myelinating rat brain

Abstract— —The ethanolamine phosphatide fraction was isolated from rat brain at 17, 19, and 22 days of age. Analysis by gas-liquid chromatography of the liberated fatty aldehydes and alkyl glyceryl ethers demonstrated a chain length composition quite distinct from that of the fatty acids in the comparable 1(3)-position of the diacyl phosphatides. [1-¹⁴C]-Acetate was administered intraperitoneally to 17-day-old rats. With the exception of the polyunsaturated fatty acids, isotope was readily incorporated into the individual side chains of the 1- and 2-positions of the glycerol moiety. Time studies revealed no readily discernible precursor-product relationships among the linkages in question. Therefore, although the long chain precursors for the alkenyl and alkyl ethers may be related by biosynthetic interconversion, the isotope data are suggestive of independent pathways of biosynthesis for the alkenyl ether, alkyl ether, and ester linkages.     

The glyceryl ethers of Paramecium phospholipids and phosphonolipids

Two glyceryl ethers, 1-O-hexadecyl glycerol and 1-O-cis-octadec-11-enyl glycerol, chimyl and paramecyl alcohol, respectively, were quantified in total phospholipids and five glycerophospholipid classes from cells and cilia of the ciliated protozoon, Paramecium tetraurelia. The ether content of 2-aminoethyl phosphonoglycerolipid was 85-90 mole %. Concentrations of ethers were greatest in the ethanolamine phosphonolipids greater than phosphatidylcholines greater than phosphatidylserines greater than phosphatidylethanolamines greater than phosphatidylinositols. The glyceryl ether concentrations in total cellular phospholipids increased with culture age in P. tetraurelia and P. multimicronucleatum cells. The glyceryl ether concentrations in the phospholipids of P. tetraurelia cilia remained constant from mid log to stationary phase of culture growth. Paramecium tetraurelia phospholipid glyceryl ether concentrations were made greater by supplementation of cultures with chimyl alcohol.     

Lipid composition of PC12 pheochromocytoma cells: characterization of globoside as a major neutral glycolipid

We have studied the lipid composition of PC12 pheochromocytoma cells cultured in the presence and absence of nerve growth factor (NGF). Neutral and acidic lipid fractions were isolated by column chromatography on DEAE-Sephadex and analyzed by high-performance thin-layer chromatography (HPTLC). The total lipid concentration was approximately 220 micrograms/mg of protein, and the concentration of neutral glycolipids was 1.6-1.8 microgram/mg of protein for both NGF-treated and untreated cells. The neutral glycolipid fraction contained a major component, which accounted for approximately 80% of the total and which was characterized as globoside on the basis of HPTLC mobility, carbohydrate analysis, fast atom bombardment mass spectrometry, and mild acid hydrolysis. The major fatty acids of globoside were C16:0 (10%), C18:0 (16%), C22:0 (23%), C24:1 (17%), and C24:0 (24%). C18 sphingenine accounted for almost all of the long-chain bases. The other neutral glycolipids were tentatively identified as glucosylceramide (15%), lactosylceramide (4%), and globotriosylceramide (4.5%). The concentration of ganglioside sialic acid was approximately 0.34 and 0.18 microgram/mg of protein for cells grown in the presence and absence of NGF, respectively. Although there was an increase in ganglioside concentration in NGF-treated cells, NGF did not produce any differential effects on the relative proportions of the individual gangliosides. Several of the gangliosides appear to contain fucose, and one of these was tentatively identified as fucosyl-GM1. Brain-type gangliosides of the ganglio series were also detected by an HPTLC-immunostaining method. However, the fatty acid and long chain base compositions of PC12 cell gangliosides (and their TLC mobility) differ from those of brain gangliosides.(ABSTRACT TRUNCATED AT 250 WORDS)     

Metabolism of α-Glyceryl Ethers by Crithidia fasciculata. I. Study of the In Vivo Degradation of Exogenous Chimyl and Batyl Alcohols1

ABSTRACT. [¹⁴C]chimyl and [³H]batyl alcohols were added to Crithidia fasciculata cultures during the mid-log phase of cell growth, and the lipid extracts of the cells were analyzed for degradation products. C. fasciculata cells were able to take up exogenous glyceryl ethers, and in amounts as high as the endogenous lipid content. The glyceryl ether taken up by the cells was incorporated into lipids either prior to the ether bond cleavage or after degradation to fatty acid. The extent of degradation and the degree of incorporation of degradation products into cellular lipid were higher for chimyl than for batyl alcohol. Batyl alcohol was not metabolized efficiently, leading to the formation of large intracellular pools of free substrate. One product of glyceryl ether degradation was identified as alkyl-dihydroxy acetone, and was detected inside and outside of the cells. The data strongly suggest that this product is the first stable intermediate in the degradation process and indicate that the extracellular formation of alkyl-dihydroxy acetone is due to the action of exocnzyme; ecteted by the cells. The constant detection of alk I cnyl glycerol among the degradation products indicates the existence of a second mechantsm in C. fasciculata for converting the alkyl-to alkenyl-glycerol.     

Triester wax: a novel neutral lipid from the skin of the rhino mutant mouse.

A novel class of neutral lipids has been isolated from the skin of the rhino mutant mouse and has been characterized as a triester wax. The lipid, on saponification and transesterification, yielded fatty acids, omega-hydroxy fatty acids and 1,2-alkane diols. These products were identified by gas-liquid and thin-layer chromatography, infrared, nuclear magnetic resonance and mass spectroscopy, combined gas-liquid chromatography and mass spectrometry and chemical methods. Fatty acids were found to be predominantly of even chain length between C14 and C36 with highest concentration at C22 : 1. Hydroxy fatty acid methyl esters (trimethylsilyl ether derivatives) showed the presence of only three components in the relative abundance of 9: 70 : 21. The structure of the major component was established as 34-hydroxytetratricont-25-enoic acid and the other two components were characterized as 32-hydroxyditricont-23-enoic and 36-hydroxyhexatricont-27-enoic acids. In addition to these omega-9 unsaturates, other isomers having unsaturation at omega-7 and omega-8 were also present in small amounts. The 1,2-alkane diols were predominantly saturated in the range of C16-C24.     

The Glyceryl Ethers of Paramecium Phospholipids and Phosphonolipids1

Two glyceryl ethers, 1-O-hexadecyl glycerol and 1-O-cis-octadec-11-enyl glycerol, chimyl and paramecyl alcohol respectively, were quantified in total phospholipids and five glycerophospholipid classes from cells and cilia of the ciliated protozoon Parammecium tetraurelia. The ether content of 2-aminoethyl phosphonoglycerolipid was 85–90 mole %. Concentrations of ethers were greatest in the ethanolamine phosphonolipids > phosphatidylcholines > phosphatidylserines > phosphatidylethanolamines > phosphatidylinositols. The glyceryl ether concentrations in total cellular phospholipids increased with culture age in P. tetraurelia and P. multimteronucleatum cells. The glyceryl ether concentrations in the phospholipids of P. tetraurelia cilia remained constant from mid log to stationary phase of culture growth. Paramecium tetraurelia phospholipid glyceryl ether concentrations were made greater by supplementation of cultures with chimyl alcohol.     

Homologues and isomers of noladin ether,a putative novel endocannabinoid: interaction with rat cannabinoid CB(1) receptors

Two regioisomers and 13 analogues of the putative endocannabinoid noladin ether (2-arachidonyl glyceryl ether, 2-AGE, 1) were synthesized and tested for their interaction with CB(1) receptors in rat brain membranes. The results showed that a C-20 tetra-unsaturated moiety is necessary for high affinity, and that a series of alkyl glyceryl ethers of potential occurrence in brain tissues have less affinity than 2-AGE for CB(1) receptors.     

Gas-liquid chromatographic analyses of 1,2-ethanediol monoethers and monoesters

Synthetic mixtures of saturated and unsaturated monoethers and monoesters of 1,2-ethanediol, ranging in chain length from 12 to 20, were analyzed as acetates, trifluoroacetates (TFA), and trimethylsilyl (TMS) ethers by gas chromatography on polar and nonpolar liquid phases. Acetates, TFA derivatives, and TMS derivatives of the glycol ethers were eluted ahead of the corresponding glycol ester derivatives on both liquid phases. The elution order of derivatives of the same compound was found to be TMS derivative before TFA derivative before acetate on the polar liquid phase, and TFA derivative before TMS derivative before acetate on the nonpolar liquid phase. Elution orders relative to methyl stearate were also determined. With one exception, all of the derivatives, and both liquid phases, were found suitable for the quantitative analysis of diol monoethers and monoesters.     

Monolayer characterstics and thermal behaviour of phosphatidic acids

The monolayer and thermal behaviour of different phosphatidic acids are presented. At neutral pH and 22°C dilauroylphosphatidic acid and unsaturated phosphatidic acids form liquid-expanded monolayers, while dipalmitoyl- and distearoylphosphatidic acid form condensed monolayers. Dimyristoylphosphatidic acid undergoes a transition from the liquid-expanded to the condensed state. With long-chain saturated and unsaturated phosphatidic acids little change in molecular area is observed between pH 2 and 7. In contrast, the short chain saturated phosphatidic acids, dilauroyl- and dimyristoylphosphatidic acids, undergo a condensation in the pH range 2 to 7. This is so in spite of the fact that the phosphoric acid group dissociates and the phosphatidic acid molecule attains one negative charge over this pH range. This finding is interpreted to indicate that the electrostatic repulsion between negatively charged phosphatidic acid molecules is compensated for or even outweighed by other intermolecular forces. Hydrogen bonding at the lipid/water interface is supposed to play a major role. All phosphatidates studied exhibit a significant expansion in the pH range 7 to 12. The second apparent pK of the primary phosphate group of phosphatidic acids is 8.6 and the expansion observed in this pH range is therefore due to electrostatic repulsion. At neutral pH the ether analogues of saturated phosphatidic acids have monolayer properties similar to those of the ester compounds. Considering the total pH range of 2 to 12 studied the force-area curves of the ether analogues are more condensed compared to the ester compounds. Synthetic phosphatidates and their ether analogues give reversible sharp crystal(gel)-to-liquid crystal transitions while the naturally occurring egg phosphatidate gives a broad, asymmetric one. The transition temperature T_m of saturated phosphatidates increases with increasing hydrocarbon chain length and at a given chain length T_m decreases markedly with unsaturation. The T_m values of the ether analogues are about 10°C higher and the ΔH values are 10–15% lower than those of the corresponding esters.     

Ehrlich ascites tumor cell surface membranes: an abnormality in ether lipid content

Most mammalian neoplasms have a defect in ether lipid content manifested by the presence of abnormally large quantities of 0-alkyl glyceryl ethers, in contrast to normal tissues in which the alk-1-enyl structure predominates. These lipids are for the most part structural. The manner in which tumor cell plasma membranes differ from normal may be important, and it has been hitherto unclear whether or not the 0-alkyl lipid abnormality of neoplasms includes the plasma membrane. The present investigation reveals that 0-alkyl lipids are present in the membranes of Ehrlich ascites tumor cells isolated by several different methods. The amount of 0-alkyl lipid, on a weight basis, represents 1-3 percent of the total phospholipids and 1-4 percent of the total aliphatic lipid. These quantities are the same as or greater than the amount of 0-alkyl lipid found in microsomes, mitochondria, and whole cell homogenate. As is generally the case for intact neoplastic tissues, the quantity of 0-alkyl lipids of Ehrlich ascites tumor plasma membrane is greater than the amount of alk-1-enyl lipids.     

A role for hormone-sensitive lipase in the selective mobilization of adipose tissue fatty acids.

The mobilization of fatty acids from rat and human fat cells is selective according to molecular structure, and notably carbon atom chain length. This study aimed at examining whether the release of individual fatty acids from triacylglycerols (TAG) by hormone-sensitive lipase (HSL) plays a role in the selectivity of fatty acid mobilization. Recombinant rat and human HSL were incubated with a lipid emulsion. The hydrolysis of 18 individual fatty acids, ranging in chain length from 12 to 24 carbon atoms and in unsaturation degree from 0 to 3 double bond(s), was measured by comparing the composition of non-esterified fatty acids (NEFA) to that of the original TAG. The relative hydrolysis (% in NEFA/% in TAG) differed between fatty acids, being about 5-fold and 3-fold higher for the most (18:1n-7) than for the least (24:0) readily released fatty acid by recombinant rat and human HSL, respectively. Relationships were found between the chain length of fatty acids and their relative hydrolysis. Among 12-24 carbon atom saturated fatty acids, the relative hydrolysis markedly decreased (by about 5- and 3-times for recombinant rat and human HSL, respectively) with increasing chain length. We conclude that fatty acids are selectively released from TAG by HSL according to carbon atom chain length. These data provide insight on the mechanism by which fatty acids are selectively mobilized from fat cells.     

Fast atom bombardment-mass spectrometric identification of molecular species of platelet-activating factor produced by stimulated human polymorphonuclear leukocytes

Fast atom bombardment mass spectrometry was used to identify molecular species of platelet-activating factor (PAF) produced by stimulated human neutrophilic polymorphonuclear leukocytes. Normal and reverse-phase high performance liquid chromatography were employed to separate the individual regions with PAF activity prior to mass spectrometric analysis. The following alkyl chain homologs of acetyl glyceryl ether phosphorylcholine (AGEPC) were found: C16:0, C17:0, C18:0 and C18:1. There was also evidence for the presence of the C15:0 homolog, as well as other species which have not yet been identified.     

Lipids from the guinea pig Harderian gland: use of picolinyl and other pyridine-containing derivatives to investigate the structures of novel branched-chain fatty acids and glycerol ethers

The lipid extracted from guinea pig Harderian glands was hydrolysed and the constituents were examined as trimethylsilyl (TMS), (2H9)TMS, methyl ester/TMS, acetonide/TMS, nicotinate/TMS, picolinyl/TMS and nicotinylidene/TMS derivatives by capillary gas-liquid chromatography and gas chromatography/mass spectrometry. Over 70 compounds amounting to over 93% of the extract were identified. These consisted of 1-O-alkyl glycerols (glycerol ethers) with alkyl chains containing from 17 to 21 carbon atoms and fatty acids ranging from 14 to 26 carbon atoms. The alkyl chains in the glycerol ethers were straight, mono- and dimethyl-branched with the major site of branching being at C-14. All straight-chain acids from C14 to C26 were present, with the most abundant being n-24:0. Again mono- and dimethyl branched structures comprised the bulk of the remaining acids. Methyl groups tended to be towards the middle of the chain rather than in the more usual omega-1 (iso) and omega-2 (anteiso) positions, with C-14 again being a major site. The shorter-chain acids tended to have methyl groups closer to the acid group, with several of the short-chain compounds being substituted at C-2. Structural information on the acids was provided by the picolinyl derivatives and the sample provided an opportunity to evaluate these derivatives with branched acids other than the iso and anteiso compounds studied previously. They were found to be satisfactory for analysis of both mono- and dimethyl branched acids with the possible exception of compounds containing a methyl branch at C-4. However, in this case, structural information was provided by the methyl ester.(ABSTRACT TRUNCATED AT 250 WORDS)     

Practical aspects of liquid chromatography-mass spectrometry (LS-MS) of lipids

Techniques for coupling liquid chromatography with mass spectrometry are reviewed and an interface is described for the analysis of lipids by mass spectrometry. The interface for coupling liquid chromatography with mass spectrometry for lipid analysis is based on the moving wire transport principle using an endless stainless steel belt of novel construction. After evaporation of the solvent, the solute remains as a residue on the belt which transports it into a reactor where it is volatilized by evaporation or conversion to hydrocarbons. The volatile compounds are then fed into the source of a chemical ionization mass spectrometer for mass analysis by total or single ion monitoring as well as for structural identification or compositional analysis. The sensitivity of the system was approx. 1 mg per component separated in the eluate of a high efficiency column. The capabilities of the interface were demonstrated by its application to reference compounds representative of triglycerides, sterols, steryl esters, glyceryl ethers, glyceryl ether diesters, glycerophosphatides, sphingolipids, prostaglandins and fatty acid methyl esters. It also was applied to the analysis of methyl ester ozonides to demonstrate the use of LC-MS for the localization of double bonds in unsaturated fatty acids.     

Differential effects of phenobarbitone and 3-methylcholanthrene induction on the hepatic microsomal metabolism and cytochrome P-450-binding of phenoxazone and a homologous series of its n-alkyl ethers (alkoxyresorufins)

The metabolism and cytochrome P-450-binding of phenoxazone and a homologous series of its n-alkyl ethers (1-8C) was studied in hepatic microsomes of control, phenobarbitone-pretreated (PB) and 3-methylcholanthrene-pretreated (3MC) C57/BL10 mice. Phenoxazone and its ethers were hydroxylated and O-dealkylated respectively to a common metabolite, resorufin. The three categories of microsomes differed greatly in activity for the metabolism and binding of the various substrate homologues. The most rapidly metabolised substrates for control microsomes were phenoxazone and its shortest-chain ethers, for PB microsomes phenoxazone and the pentyl ether, and for 3MC microsomes the ethyl and propyl ethers. The variations in activity occurred in Vmax rather than in the apparent K_m-value. All the ethers gave Type I cytochrome P-450-binding spectra. The substrates giving the largest Type I spectra were the same for all microsomes—the ethyl, propyl and butyl ethers—but the magnitudes of the spectra differed in the order 3MC- > PB- > control microsomes. Phenoxazone and resorufin gave Modified Type II cytochrome P-450-binding spectra. PB-induction was most marked for the depentylation reaction (increased 101-fold), whereas 3MC-induction was most marked for depropylation and debutylation (88- and 96-fold).The intermicrosomal differences were interpreted as reflecting the different metabolic specificities of variant forms of cytochrome P-450. Substrate lipophilicity increased with increasing ether chain length and was not a major influence on specificity. The main substrate influence on specificity was steric, due to the presence and length of the ether side chain. The preeminent effect of ether chain length was considered to be on the rate of substrate transformation rather than on substrate interaction with cytochrome P-450.     

Identification of 1-alkyl-2-acyl-3-(2',3'-diacylglycerol)glycerols, a new type of lipid class, in harderian gland tumors of mice

A new class of alkyl glycerolipids, 1-alkyl-2-acyl-3-(2',3'-diacylglycerol)glycerols, was identified in lipid extracts prepared from harderian gland tumors of mice. After saponification, this lipid class yielded 1-alkyl-3-(1'-glycerol)glycerols. Identification was based on mass spectrometry, proton nuclear magnetic resonance spectroscopy, infrared spectroscopy, and chromatography of various derivatives and appropriate standards that were synthesized. The alkyl moieties of this unique lipid class consisted of saturated aliphatic chains with chain lengths of 14 to 20 carbon atoms. The acyl moieties were mostly saturated and monounsaturated aliphatic chains ranging from 14 to 24 carbon atoms. The alkyl and acyl moieties of 1-alkyl-2-acyl-3-(2',3'-diacylglycerol)glycerols were similar to those of alkyldiacylglycerols present in the same tissue, except for the presence of monounsaturated alkyl moieties in the latter. 1-Alkyl-2-acyl-3-(2', 3'-diacylglycerol)glycerols were only found in trace amounts in the normal harderian glands of mice. The total quantity of the alkyl and acyl moieties with a chain length greater than 20 carbon atoms in the alkyldiacylglycerols from tumors were considerably lower than those found in normal harderian glands of mice. This is the first report of the presence of bisglyceryl ether lipids in mammalian tissue; its unique chemical structure is consistent with the type of ether-linked lipid products that could be synthesized in the reaction catalyzed by alkyldihydroxyacetone-P synthase.     

Effects of two different medium-chain triglycerides (tri C8:O and tri C12:O) on liver lipids in the growing rat.

Results presented in this study emphasize the long-term effects of dietary fatty acid chain length on some biochemical parameters of the liver in the growing rat. High levels of medium-chain fatty acids feeding (C8:O and C12:O) from 40 to 340 g of body weight induced liver growth and lipid contents intermediary between values recorded with a lipid-free diet and with a diet containing long-chain fatty acids. No steatosis was recorded but neutral lipid contents appeared to be correlated with the dietary fatty acid chain length while phospholipid contents remained much more stable. In the four tested nutritional conditions, only dodecano?c or lauric acid (C12:O) feeding induced important alterations in the fatty acid pattern of liver neutral lipids. Medium-chain fatty acids, and even lauric acid which was intensely esterified in adipose tissue triglycerides, did not appreciably modify the fatty acid composition of liver phospholipids and were not esterified in it.     

The isolation and identification of 2,4-diketones present in human and animal tissues and in urine.

The chemical isolation of 2,3-diketone fraction from hydrolysates of various mammalian tissues has been accomplished by the use of a modified Girard T procedure. This fraction, which constitutes a new lipid class, has been resolved by gas chromatography into a number of homologous 2,4-diketones, ranging in chain length from C13 to C25. After separation by preparative gas chromatography, the following compounds have been unequivocally identified: 2,4-heptadecanedione, 2,4-nonadecanedione, 2,4-heneicosanedione, 2,4-docosanedione, and delta12-2,4-heneicosenedione. The 2,4-diketones appear to exist in tissues in the free state or in labile combination. They are present also in human urine.     

Reactive chlorinating species produced by myeloperoxidase target the vinyl ether bond of plasmalogens: identification of 2-chlorohexadecanal

Plasmalogens contain a vinyl ether bond linking the sn-1 aliphatic chain to the glycerol backbone of this predominant phospholipid molecular subclass, which is found in many mammalian tissues. The present study demonstrates that the vinyl ether bond of plasmalogens is a molecular target of the reactive chlorinating species produced by myeloperoxidase. Analysis by thin layer chromatography revealed that reactive chlorinating species produced by myeloperoxidase target the vinyl ether bond of the plasmalogen, lysoplasmenylcholine (1-O-hexadec-1'-enyl-sn-glycero-3-phosphorylcholine), resulting in the production of a neutral lipid. Capillary gas chromatographic analyses demonstrated that the neutral lipid generated from lysoplasmenylcholine was neither hexadecanal nor did it contain masked hexadecanal (i.e. the vinyl ether) because the dimethyl acetal of hexadecanal produced by acid methanolysis derivatization was no longer present. Electrospray ionization mass spectrometry of the myeloperoxidase-generated neutral lipid product was consistent with the production of a 16-carbon fatty aldehyde containing one chlorine atom. Furthermore, proton NMR analysis indicated that this neutral lipid product was a 2-chloro-fatty aldehyde. Additional structural analysis of this neutral lipid by gas chromatography-mass spectrometry of the underivatized product as well as its pentafluorobenzyl oxime-derivative product was consistent with the neutral lipid being 2-chlorohexadecanal. The reactive chlorinating species, hypochlorous acid and chlorine gas, both attacked the vinyl ether bond of lysoplasmenylcholine resulting in the production of 2-chlorohexadecanal. The production of 2-chlorohexadecanal was dependent on the presence of the plasmalogen masked aldehyde (i.e. the vinyl ether) in the substrate because the free fatty aldehyde, hexadecanal, was not converted to 2-chlorohexadecanal by the reactive chlorinating species generated by myeloperoxidase. Taken together, the present studies demonstrate for the first time the targeting of the vinyl ether bond of plasmalogens by the reactive chlorinating species produced by myeloperoxidase resulting in the production of novel chlorinated fatty aldehydes.