Chain Saturated Fatty Acids Research Articles

Isolation and characterization of acidic glycosphingolipids from the gill of the Pacific Salmon (Oncorhynchus keta): A novel hybrid-type ganglioside with isoglobo- and neolacto-Series

Monosialosyl gangliosides and sulfoglycolipids in the gill of pacific salmon, Oncorhynchus keta, have been prepared by solvent extraction and DEAE-Sephadex column chromatography. Acidic glycolipid bands (M1-M13) detected by thin layer chromatography were separated by Iatrobeads column chromatography and 13 components were characterized by TLC, compositional analysis, methylation analysis, chemical and enzymatic degradation, liquid secondary ion mass spectrometry and (1)H nuclear magnetic resonance spectroscopy. In addition to the acidic glycolipids with known structures (SM4s, SM3, GM3, LM1, GM1b and V(3)alphaFuc,IV(3)betaGalNAc-GM1a), two fractions (M11 and M13) of unknown monosialosyl gangliosides with TLC mobility slower than GM1a were isolated and characterized as having the following structure with a hybrid of isoglobo- and neolacto-series. [formula: see text] Analysis of fatty acid indicated predominance of C24:1 fatty acid in the upper band (M11) and shorter chain saturated fatty acids in the lower band (M13). The tissue concentrations of M11 and M13 were 1.15 and 0.96 mumol/kg wet weight, respectively.

Structural analysis of a unique hybrid-type ganglioside with isoglobo-, neolacto-, and ganglio-core from the gills of the Pacific salmon ( Oncorhynchus keta)

Monosialosyl gangliosides from the gills of the Pacific salmon, Oncorhynchus keta, have been prepared by solvent extraction and DEAE-Sephadex column chromatography. The unknown acidic glycolipids (M14 and M15) with slower mobility than GM1a on thin-layer chromatography were separated by Iatrobeads column chromatography and were characterized by compositional analysis, methylation analysis, chemical, and enzymatic degradation, negative-ion LSIMS, and 1H nuclear magnetic resonance spectroscopy. Both M14 and M15 contained a same oligosaccharide core with isoglobo-, neolacto-, and ganglio-series as follows: [Display omitted] The only difference between M14 and M15 was in fatty acid acylation. Analysis of the fatty acids indicated a predominance of C24:1 fatty acid in M14 and shorter chain saturated fatty acids, C14:0 and C16:0, in M15.

Effect of essential oil of Citrus cinensis cv new hall – Citrus aurantium (indigenous in Greece) upon growth of Yarrowia lipolytica

The effect of essential oil from Citrus cinensis cv new hall – Citrus aurantium (indigenous in Greece) upon growth of the dimorphic non-conventional yeast Yarrowia lipolytica strain ACA-DC 50109 was studied. The microorganism was aerobically cultivated in batch mode in carbon-limited media. The essential oil was added into the culture medium in different quantities while the control experiment was carried out without addition. The essential oil caused a relatively important decrease of the highest concentration of biomass produced. Additionally, biomass yield on glucose consumed was significantly decreased with the addition of the oil on the cultivation medium. Moreover, the addition of the essential oil considerably increased the lag time of the culture. In all trials, a remarkable drop the pH value of the medium was observed due to the biosynthesis of small amounts of organic acids. Given that one principal component of this membrane is the one of cellular lipids, it was assumed that the extraction and the analysis of cellular lipids could provide information about the microbial behaviour. Total lipids were extracted, methanolyzed and analyzed with the aid of G.L.C. In the control experiment, the culture conditions did not favour accumulation of storage lipid inside the yeast cells and, hence, lipid produced corresponded to 5–9% (wt/wt) in dry cell mass. Similar concentrations of cellular lipids were produced when essential oil was added in various amounts. When essential oils were added, an increase of lower aliphatic chain saturated fatty acids was observed, suggesting an alteration in the membrane function.

Decomposition of a long chain saturated fatty acid with some additives in hot compressed water

Stearic acid (C 17 H 35 COOH: C 17 -acid) was treated using a batch reactor with supercritical water (SCW) of 673 K and 0.17 g/cm 3 for 30 min. In SCW, C 17 -acid was stable (2% conversion) and the main products were CO 2 and C 16 alkene. An addition of alkali hydroxide (NaOH and KOH) in the SCW reaction enhanced the decarboxylation of C 17 -acid with the main products being CO 2 and C 17 alkane. Metal oxides (CeO 2 , Y 2 O 3 and ZrO 2 ) enhanced the decarboxylation of C 17 -acid and the main products were CO 2 and C 16 alkene. Based on the results, the reaction mechanism was proposed.

Product/Process integration in food manufacture: Engineering sustained health

Product/Process integration in food manufacture: Engineering sustained health

Structured triglycerides containing caprylic (8:0) and oleic (18:1) fatty acids reduce blood cholesterol concentrations and aortic cholesterol accumulation in hamsters

The effects of structured triglycerides containing one long chain fatty acid (oleic acid, C18:1) and one short chain saturated fatty acid (caprylic acid, 8:0) on lipidemia, liver and aortic cholesterol, and fecal neutral sterol excretion were investigated in male Golden Syrian hamsters fed a hypercholesterolemic regimen consisting of 89.9% commercial ration to which was added 10% coconut oil and 0.1% cholesterol (w/w). After 2 weeks on the HCD diet, the hamsters were bled, following an overnight fast (16 h) and placed into one of three dietary treatments of eight animals each based on similar plasma cholesterol levels. The hamsters either continued on the HCD diet or were placed on diets in which the coconut oil was replaced by one of two structured triglycerides, namely, 1(3),2-dicaproyl-3(1)-oleoylglycerol (OCC) or 1,3-dicaproyl-2-oleoylglycerol (COC) at 10% by weight. Plasma total cholesterol (TC) in hamsters fed the OCC and COC compared to the HCD were reduced 40% and 49%, respectively ( P < 0.05). Similarly, hamsters fed the OCC and COC diets reduced their plasma nonHDL cholesterol levels by 47% and 57%, respectively ( P < 0.05), compared to hamsters fed the HCD after 2 weeks of dietary treatment. Although hamsters fed the OCC (−26%) and COC (−32%) had significantly lower plasma HDL levels compared to HCD, ( P < 0.05), the plasma nonHDL/HDL cholesterol ratio was significantly lower ( P < 0.05) compared to the HCD for the OCC-fed (−27%) and the COC-fed (−38%) hamsters, respectively. Compared to the HCD group, aortic esterified cholesterol was 20% and 53% lower for the OCC and COC groups, respectively, with the latter reaching statistical significance, P < 0.05. In conclusion, the hamsters fed the structured triglyceride oils had lower blood cholesterol levels and lower aortic accumulation of cholesterol compared to the control fed hamsters.

Diesel Combustion Characteristics of Coconut Oil Methyl Ester

Coconut oil has high content of straight chain saturated fatty acids such as lauric acid. Also it contains 14.5 wt% of oxygen, which is about 4 wt% more oxygen than that of rapeseed oil. The purpose of this study is to investigate the utilization of coconut oil methyl ester (CME) as a biodiesel fuel for diesel engines. Therefore, the diesel combustion characteristics and exhaust emissions of CME are investigated by using a small DI diesel engine and comparing with rapeseed oil methyl ester (RME) and gas oil. From the experiment results, CME has the better ignitability and the same thermal efficiency as the other test fuels. Both Smoke and NOx emissions from CME are lower than that from RME and gas oil. Therefore CME can be used as an alternative fuel of petroleum based diesel fuel.

Incorporation of branched-chain fatty acid into cellular lipids and caspase-independent apoptosis in human breast cancer cell line, SKBR-3

Background13-Methyltetradecanoic acid (13-MTD), an iso-C15 branched- chain saturated fatty acid, has been shown to induce apoptotic cell death of numerous human cancer cells. However, the mechanism for the induction of apoptosis has not been fully understood. This study described the incorporation of 13-MTD into cellular lipid of SKBR-3 breast cancer cells and apoptosis related event to gain more insight into the mechanism action of this fatty acid.ResultsTreatment of SKBR-3 cells with 13-MTD lowered the cell viability and induced apoptosis. Proportion of 13-MTD in the glycerolipids increased to saturation level within 6 hours. Triacylglycerol contained 13-MTD in higher concentration than phospholipid with positional preference to sn-2. 13-MTD caused no changes in the caspase activity and its gene expression. Furthermore, addition of caspase-inhibitor to culture medium did not prevent the cells from the cytotoxicity of 13-MTD. No-increase in the cellular calcium level was also noted with 13-MTD treatment. However, 13-MTD disrupted the mitochondrial integrity in 4 hours, and increased the nuclear translocation of apoptosis inducing factor.ConclusionThese results showed that 13-MTD disrupted the mitochondrial integrity, and induced apoptosis via caspase-independent death pathway.

Coconut oil as base oil for industrial lubricants—evaluation and modification of thermal, oxidative and low temperature properties

This paper presents the thermo-gravimetric analysis (TGA) of coconut oil, sesame oil, sunflower oil and a commercial 2T oil under nitrogen and oxygen environment to study their thermal and oxidative degradation and the analysis of the low-temperature properties of the vegetable oils using differential scanning calorimetry (DSC). A molecular dynamics simulation software (Spartan 02, Wavefunction Inc.) has been used to study the effect of different saturated and unsaturated fatty acid (e.g. lauric, oleic, linoleic) chains on pour point. Coconut oil showed lower weight gain, an indicator of oxidative stability, under oxidative environment and the highest pour point among the vegetable oils considered in the study. This can be attributed to the predominantly saturated nature of its fatty acid constituents. The procedures described in this paper have been effective in improving the oxidative stability and the pour point of coconut oil to some extent.

Fatty acid composition of mature breast milk in Brazilian women

This work analyzed the fatty acid composition of mature milk samples, weekly obtained from eight Brazilian women between the 4th and 13th lactation weeks. A questionnaire was weekly applied to observe their eating habits. Saturated fatty acids constituted 39.7% of the total fatty acids. De novo fatty acids and long chain saturated fatty acids presented levels of 15.9% and 23.8%, respectively. trans-Fatty acid content was very low (2.36%). Unsaturated fatty acids constituted 50.9% of the total fatty acids, with over half being monounsaturated fatty acids (27.6%). Polyunsaturated fatty acids showed levels of 23.3%, with high linoleic and α-linolenic acid contents (20.3% and 1.43%, respectively). Arachidonic acid had a content of 0.53%, while docosahexaenoic acid content was 0.14%, values considered adequate for the needs of breast-fed infants.

Structural characterization of fatty acids cationized with copper by electrospray ionization mass spectrometry under low‐energy collision‐induced dissociation

Fatty acids have for many years been characterized by mass spectrometry using electron ionization after chemical derivatization. When fatty acids are ionized using desorption/ionization methods such as electrospray ionization or fast atom bombardment, structural information is usually obtained through high-energy collision-induced dissociation (CID) using sector instruments. It has been shown that copper displays very interesting properties in the gas phase during CID. In this study, the reactivity of saturated and unsaturated fatty acid-copper [M-H+Cu(II)]+ complex and the role of the copper ion in promoting fragmentations were investigated under low-energy collisional activation conditions. The decomposition of these species in an ion trap instrument led to diagnostic ion series that reflect C--C bond cleavage, which involves Cu(II) reduction followed by the release of an alkyl radical. It was demonstrated that in this way the localization of one or two homoconjugated double bonds is possible using low-energy CID. Moreover, the distinction of cis and trans isomers is possible through characteristic product ions related to a specific loss of CO2. When these experiments are repeated using a triple-quadrupole instrument with argon as collision gas, a different behavior is observed as in this case, in addition to the product ion distributions observed in the ion trap, other distributions are observed that reflect the influence of the different kinetic shifts and the occurrence of consecutive decompositions. Different examples are presented with various saturated and unsaturated fatty acid chains. Mechanisms are proposed in order to rationalize the experimental observations.

Retardation Effects of Polyglycerol Fatty Acid Esters on the Crystallization of n-Hexadecane

In this study, we investigated the effects of two types of polyglycerol fatty acid esters, both of which were made from the same polar group of polymerized 10 glycerols, on the crystallization of n-hexadecane (n-HD). One of the emulsifiers, known as THL-17, consists of three different saturated fatty acid chains with different carbon numbers between 8 and 18. Another emulsifier, known as 10G10S, contains a stearic acid chain only. The two emulsifiers were added to retard the crystallization rate of n-HD, which has melting point of 18.0°C, and was chosen as a model fat material. Visual and optical microscopic observations showed that the growth of n-HD seed crystals in bulk liquid was significantly retarded by the addition of 1.0 wt.% THL-17 at 17.0°C. The DSC cooling peaks of n-HD with and without the addition of THL-17 showed that the crystallization temperature (Tc) of n-HD decreased with increasing concentrations of THL-17 from 15.9°C (in the pure form) to 14.0°C (in the solution containing 1.0 wt.% THL-17). In contrast, 10G10S did not affect the Tc value, even at a concentration of 1.0 wt.%. The results of this study suggest that the inhibition of n-HD crystal formation in the presence of THL-17 results from effects on both crystal nucleation and post-nucleation crystal growth processes.

Seed-specific heterologous expression of a nasturtium FAE gene in Arabidopsis results in a dramatic increase in the proportion of erucic acid.

The fatty acid elongase [often designated FAE or beta-(or 3-) ketoacyl-CoA synthase] is a condensing enzyme and is the first component of the elongation complex involved in synthesis of erucic acid (22:1) in seeds of garden nasturtium (Tropaeolum majus). Using a degenerate primers approach, a cDNA of a putative embryo FAE was obtained showing high homology to known plant elongases. This cDNA contains a 1,512-bp open reading frame that encodes a protein of 504 amino acids. A genomic clone of the nasturtium FAE was isolated and sequence analyses indicated the absence of introns. Northern hybridization showed the expression of this nasturtium FAE gene to be restricted to the embryo. Southern hybridization revealed the nasturtium beta-ketoacyl-CoA synthase to be encoded by a small multigene family. To establish the function of the elongase homolog, the cDNA was introduced into two different heterologous chromosomal backgrounds (Arabidopsis and tobacco [Nicotiana tabacum]) under the control of a seed-specific (napin) promoter and the tandem 35S promoter, respectively. Seed-specific expression resulted in up to an 8-fold increase in erucic acid proportions in Arabidopsis seed oil, while constitutive expression in transgenic tobacco tissue resulted in increased proportions of very long chain saturated fatty acids. These results indicate that the nasturtium FAE gene encodes a condensing enzyme involved in the biosynthesis of very long chain fatty acids, utilizing monounsaturated and saturated acyl substrates. Given its strong and unique preference for elongating 20:1-CoA, the utility of the FAE gene product for directing or engineering increased synthesis of erucic acid is discussed.

Influences of fatty acid moiety and esterification of polyglycerol fatty acid esters on the crystallization of palm mid fraction in oil-in-water emulsion

We examined the crystallization of palm mid fraction (PMF) in oil-in-water (O/W) emulsion, after adding polyglycerol fatty acid esters (PGFEs). We employed ultrasonic velocity measurements and DSC techniques, with special emphases on the influences of fatty acid moiety and esterification of PGFE. Twelve types of PGFEs were examined as additives. PGFEs have a large hydrophilic moiety composed of 10 glycerol molecules to which palmitic, stearic and behenic acids were esterified as the fatty acid moiety with different degrees of esterification. Crystallization temperature ( T c) of PMF remarkably increased with increasing concentrations of the PGFEs as the chain length of the fatty acid moiety increased, and the PGFE became more hydrophobic in accordance with increasing degree of esterification. We observed that the heterogeneous nucleation of PMF in the O/W emulsion was activated at the oil–water interface, where the template effect of very hydrophobic long saturated fatty acid chains of the PGFE might play the main role of heterogeneous nucleation.

Membrane Synthesis, Specific Lipid Requirements, and Localized Lipid Composition Changes Associated with a Positive-Strand RNA Virus RNA Replication Protein

Multifunctional RNA replication protein 1a of brome mosaic virus (BMV), a positive-strand RNA virus, localizes to the cytoplasmic face of endoplasmic reticulum (ER) membranes and induces ER lumenal spherules in which viral RNA synthesis occurs. We previously showed that BMV RNA replication in yeast is severely inhibited prior to negative-strand RNA synthesis by a single-amino-acid substitution in the ole1w allele of yeast Delta9 fatty acid (FA) desaturase, which converts saturated FAs (SFAs) to unsaturated FAs (UFAs). Here we further define the relationships between 1a, membrane lipid composition, and RNA synthesis. We show that 1a expression increases total membrane lipids in wild-type (wt) yeast by 25 to 33%, consistent with recent results indicating that the numerous 1a-induced spherules are enveloped by invaginations of the outer ER membrane. 1a did not alter total membrane lipid composition in wt or ole1w yeast, but the ole1w mutation selectively depleted 18-carbon, monounsaturated (18:1) FA chains and increased 16:0 SFA chains, reducing the UFA-to-SFA ratio from approximately 2.5 to approximately 1.5. Thus, ole1w inhibition of RNA replication was correlated with decreased levels of UFA, membrane fluidity, and plasticity. The ole1w mutation did not alter 1a-induced membrane synthesis, 1a localization to the perinuclear ER, or colocalization of BMV 2a polymerase, nor did it block spherule formation. Moreover, BMV RNA replication templates were still recovered from cell lysates in a 1a-induced, 1a- and membrane-associated, and nuclease-resistant but detergent-susceptible state consistent with spherules. However, unlike nearby ER membranes, the membranes surrounding spherules in ole1w cells were not distinctively stained with osmium tetroxide, which interacts specifically with UFA double bonds. Thus, in ole1w cells, spherule-associated membranes were locally depleted in UFAs. This localized UFA depletion helps to explain why BMV RNA replication is more sensitive than cell growth to reduced UFA levels. The results imply that 1a preferentially interacts with one or more types of membrane lipids.

Characterization of soil microbial communities under different potato cropping systems by microbial population dynamics, substrate utilization, and fatty acid profiles

The effects of 11 different 2- and 3-yr potato crop rotations on soil microbial communities were characterized over three field seasons using several techniques. Assessments included microbial populations determined by soil dilution plate counts on various general and selective culture media, microbial activity by fluorescein diacetate (FDA) hydrolysis, single carbon source substrate utilization (SU) profiles, and fatty acid methyl ester (FAME) profiles. Potato rotation crops evaluated in research plots at Newport, ME, included barley/clover, canola, green bean, millet, soybean, sweet corn, and a continuous potato control. Soil populations of culturable bacteria and overall microbial activity tended to be highest following barley, canola, and sweet corn rotations, and lowest with continuous potato. Differences among rotations were less apparent during the potato phase of the rotations. Populations of actinomycetes and fluorescent pseudomonads tended to be greater in barley rotations than in most other rotations. SU profiles derived from BIOLOG GN2 plates indicated that certain rotations, including barley, canola, and sweet corn tended to have higher overall microbial activity, and barley and sweet corn rotations averaged higher substrate richness and diversity. Soybean and potato rotations tended to have lower substrate richness and diversity. Principal component analyses of SU data revealed differences among rotation soil communities in their utilization of individual carbon sources and substrate guilds, including carbohydrates, carboxylic acids, amines/amides, and amino acids. Analyses of soil FAME profiles demonstrated distinct differences among all the rotation soils in their relative composition of fatty acids, indicating differences in their microbial community structure. Fatty acids most responsible for differentiation among rotation soils included 16:1 ω5c, 16:1 ω7c, 18:2 ω6c, 18:1 ω9c, 12:0, and 13:0 anteiso, with 16:1 ω5c being the single greatest determinant. Overall, monounsaturated fatty acids, particularly 16:1 ω5c, were most prevalent in sweet corn rotations and polyunsaturates were highest in barley and millet rotations. Straight chain saturated fatty acids comprised the greatest proportion of fatty acids in soils under continuous potato. FAME biomarkers for microorganism groups indicated barley and millet rotations had the highest ratio of fungi to bacteria, and soybean and continuous potato had the lowest ratio. This research has demonstrated that different crop rotations have distinctive effects on soil microbial communities that are detectable using a variety of techniques. Further studies will identify more specific changes associated with particular rotations and relate these changes to potential effects on disease management, crop health, and crop productivity.

Comprehensive and uniform synthesis of all naturally occurring phosphorylated phosphatidylinositols.

Studies of cellular signal transduction mechanisms involving receptor-mediated generation of inositol phosphates and phosphorylated phosphatidylinositols require easy access to these naturally occurring products. Although numerous synthetic methods have been developed during the past decade, most of these methods suffer from excessive length and lack of generality. In this work we describe the comprehensive and uniform synthesis of all naturally occurring phosphatidylinositols such as phosphatidylinositol, phosphatidylinositol 3-phosphate, 4-phosphate, 5-phosphate, 3,4-bisphosphate, 3,5-bisphosphate, 4,5-bisphosphate, and 3,4,5-trisphosphate, featuring both saturated and unsaturated fatty acid chains.

Effect of octanoic acid on ethylene-mediated processes in Arabidopsis

We have examined whether octanoic acid (OA) one of the short chain saturated fatty acids (SCSFA), increases ethylene response in the following three ethylene-mediated processes: a) hypocotyl growth in darkness; b) formation of new flowers; c) flower abscission. These processes were examined in the presence or absence of exogenous ethylene in Arabidopsis wild type (WT) and in the ethylene-insensitive mutants, etr1-3 and ein2-1 and in the ethylene over-producer mutant eto1-1. Our results show that OA decreased hypocotyl length of WT in the absence or presence of exogenous ethylene, apparently showing that OA acts via augmentation of ethylene action. However, the hypocotyl growth inhibition could not be ascribed to increased ethylene sensitivity since application of inhibitors of ethylene synthesis (aminoethoxyvinylglycine; AVG) or action (1-methylcyclopropene;1-MCP) to WT seedlings did not prevent specifically the OA-induced growth inhibition. Also, OA inhibited hypocotyl growth in the mutants etr1-3 and ein2-1 in a similar pattern to that obtained in WT. On the other hand, OA had no effect on flower formation neither in WT, etr1-3 and eto1-1, in which ethylene reduced flower formation, nor in the ein2-1 mutant, in which ethylene had no effect. OA also did not increase flower abscission in WT or in the mutants etr1-3 and ein2-1 neither in the absence nor in the presence of ethylene. However, OA has augmented flower abscission in the mutant eto1-1 only in the absence of exogenous ethylene. This result might indicate that the effect of OA on eto1-1 is specific to this mutant and is not due to general deleterious effects inflicted by OA. Taken together, our results show that in general OA does not augment ethylene response in Arabidopsis, but it might affect ethylene action in flower abscission of the ethylene-overproducer mutant.

Kinetic analysis of hydroxylation of saturated fatty acids by recombinant P450foxy produced by an Escherichia coli expression system.

Cytochrome P450foxy (P450foxy, CYP505) is a fused protein of cytochrome P450 (P450) and its reductase isolated from the fungus Fusarium oxysporum, which catalyzes the subterminal (omega-1 approximately omega-3) hydroxylation of fatty acids. Here, we produced, purified and characterized a fused recombinant protein (rP450foxy) using the Escherichia coli expression system. Purified rP450foxy was catalytically and spectrally indistinguishable from the native protein, but most of the rP450foxy was recovered in the soluble fraction of E. coli cells unlike the membrane-bound native protein. The results are consistent with our notion that the native protein is targeted to the membrane by a post-translational modification mechanism. We also discovered that P450foxy could use shorter saturated fatty acid chains (C9 and C10) as a substrate. The regiospecificity (omega-1 approximately omega-3) of hydroxylation due to the enzymatic reaction for the short substrates (decanoate, C10; undecanoate, C11) was the same as that for longer substrates. Steady state kinetic studies showed that the kcat values for all substrates tested (C9-C16) were of the same magnitude (1200-1800 min-1), whereas the catalytic efficiency (kcat/Km) was higher for longer fatty acids. Substrate inhibition was observed with fatty acid substrates longer than C13, and the degree of inhibition increased with increasing chain length. This substrate inhibition was not apparent with P450BM3, a bacterial counterpart of P450foxy, which was the first obvious difference in their catalytic properties to be identified. Kinetic data were consistent with the inhibition due to binding of the second substrate. We discuss the inhibition mechanism based on differences between P450foxy and P450BM3 in key amino acid residues for substrate binding.

LC-MS analysis of pig intestine sulfatides: interaction with Escherichia coli STb enterotoxin and characterization of molecular species present.

STb, a 48-amino acid thermostable enterotoxin is produced by enterotoxigenic Escherichia coli strains and is responsible for diarrheal diseases in many animals, including man. Our laboratory recently identified a family of molecules, from a lipid extract of porcine intestinal epithelial cells, that could bind to STb. These molecules were identified as sulfatides as they reacted with a monoclonal antibody raised against this family of molecules. However, as the epitope recognized by this monoclonal antibody was the galactose 3-sulfate, a doubt could remain as to the exact nature of the identified receptors. The goal of this study was thus to confirm the chemical nature of the STb-binding molecule as sulfatides or as distinctive molecules comprising a sulfated galactosyl residue. Using a thin-layer chromatography-overlay method we confirmed using antibodies to STb that STb recognizes the commercial sulfatides and a band migrating at the same level from the intestinal tissue lipid extract obtained from an 8-week-old piglet. The compounds recovered from the silica gel plates were analyzed by mass spectrometry in electrospray negative-ionization mode. The most abundant ions observed had m/z values of 779, 795, 879 and 907. For commercial bovine brain sulfatides the ions 795, 879 and 907 have been attributed to hydroxylated sulfatides with a saturated fatty acid chain containing 16, 22 and 24 carbons, while the 779 ion contained a saturated fatty acid chain of 16 carbons. The general profile of the ions observed was similar to the already described commercial bovine brain sulfatides.