Characterization of two glucuronic acid-containing glycosphingolipids in larvae of the green-bottle fly, Lucilia caesar

Two glucuronic acid-containing glycosphingolipids were purified from larvae of the green-bottle fly, Lucilia caesar by DEAE-Sephadex and Iatrobeads column chromatography. Structures of these acidic glycolipids, glycolipids X and Y, were elucidated by means of sugar analysis, permethylation, enzymatic hydrolysis, negative-ion fast atom bombardment mass spectrometry, and NMR studies. Glycolipid X was determined to have the following structure: GlcA beta 1-3Gal beta 1-3GalNAc alpha 1-4 GalNAc beta 1-4 GlcNAc beta 1-3Man beta 1-4Glc beta 1-1 ceramide. The other acidic glycolipid, glycolipid Y contains a phosphoethanolamine residue linked through the 6-hydroxy group of the N-acetyl-glucosamine unit of glycolipid X. The ceramide moieties were composed of saturated fatty acids (16:0-22:0) and tetradeca- and hexadeca-4-sphingenines. Based on the structural similarity of the ceramide moieties it appears likely that glycolipid X is an intermediate from which glycolipid Y is synthesized by addition of a phosphoethanolamine residue.     

Characterization of a diphosphonopentaosylceramide containing 3-O-methylgalactose from the skin of Aplysia kurodai (sea hare)

The complete structure is proposed for a ceramide (Cer), bis(2-aminoethylphosphono)-pentaoside, isolated from the skin of Aplysia kurodai. This new phosphonoglycosphingolipid was purified using two systems of column chromatography on silicic acid. The purity of the glycolipid was confirmed by thin-layer chromatography, analysis of its composition, and proton magnetic resonance spectrometry. The component carbohydrates were glucose, galactose, N-acetylgalactosamine, and 3-O-methylgalactose. Most (90%) of the fatty acid was palmitic acid and the major sphingosine bases were octadeca-4-sphingenine (51%) and anteisononadeca-4-sphingenine (38%). 2-Aminoethylphosphonyl-6-galactose was identified after its partial hydrolysis. From studies by methanolysis, permethylation, mild acid hydrolysis, hydrogen fluoride treatment, chromium trioxide oxidation combined with thin-layer chromatography, gas liquid chromatography, gas chromatography-mass spectrometry, and proton magnetic resonance spectrometry, the structure of the glycolipid was concluded to be 3-OMeGal beta 1----3GalNAc alpha 1----3[6'-O-(2-aminoethylphosphonyl)-Gal alpha 1----2](2-aminoethylphosphonyl----6)Gal beta 1----4Glc beta 1----1Cer.     

The occurrence of glycosphingolipids containing mannose in the sea-water bivalve, Meretrix lusoria (Hamaguri)

Total neutral and acidic glycosphingolipids were prepared from whole tissues of the sea-water bivalve, Meretrix lusoria, and the former preparation was further fractionated into subgroups by silicic acid column chromatography. The fractions obtained as mono-(ceramide monosaccharide, CMS), di-(CDS) and triglycosylceramides (CTS) were characterized by thin-layer chromatography, partial hydrolysis with exoglycosidases, methylation studies, CrO3 oxidation, and GLC analysis of the component sugars, fatty acids and long-chain bases. The following structures are proposed: Gal-Cer and Glc-Cer for CMS, Gal(beta 1----4)Glc-Cer and Man(beta 1----4)Glc-Cer (MlOse2Cer) for CDS, Man(alpha 1----3)Man(beta 1----4)Glc-Cer (MlOse3Cer) and Gal(alpha 1----3)Man(beta 1----4)Glc-Cer (II3 alpha Gal-MlOse2Cer) for CTS. To our knowledge II3 alpha Gal-MlOse2Cer has not previously been reported. The fatty acid composition of CMS, CDS, and CTS consisted almost entirely of saturated C16-C24 acids with large amounts of 2-hydroxypalmitic acid and 2-hydroxystearic acid. The long-chain bases consisted of 4-sphingenine and 4,8-sphingadienine. More complex neutral glycolipids than CTS, as well as an acidic glycolipid, were examined by TLC and GLC of the constituent sugars, and an immunochemical technique.(ABSTRACT TRUNCATED AT 250 WORDS)     

Glycosphingolipids in cestodes. Chemical structures of ceramide monosaccharide, disaccharide, trisaccharide and tetrasaccharide from metacestodes of the fox tapeworm, Taenia crassiceps (Cestoda: Cyclophyllidea).

The presence of glycosphingolipids in the metacestodes of the fox tapeworm, Taenia crassiceps, has been established. The normal-phase TLC pattern of the neutral-fraction glycolipids revealed groups of bands corresponding to homologous components of increasing sugar chain length. The three simplest glycolipid components have been isolated and their chemical constitution determined as being of the neogala series: Gal beta 1Cer, Gal beta 6Gal beta 1Cer and Gal beta 6Gal beta 6Gal beta 1Cer. The ceramide tetrasaccharide fraction has been found to consist of a mixture of neogalatetraosylceramide, as an elongation of the neogala series, Gal beta 6Gal beta 6Gal beta 6Gal beta 1Cer and the component Gal alpha 4Gal beta 6Gal beta 6Gal beta 1Cer (both occurring in approximately equimolar proportions). The long-chain bases of the ceramide monogalactoside, digalactoside, trigalactoside and tetragalactosides contain, as well as small amounts of sphingosine, predominantly dihydrosphingosine/phytosphingosine in the approximate ratios 1.7:1, 1.4:1, 1:1 and 2.3:1, respectively. The major ceramide fatty acids have particularly long chains, with hexacosanoic and octacosanoic acids predominating. Upon reverse-phase TCL, the glycolipid components ceramide monogalactoside, digalactoside and trigalactoside were each separable into five component bands. Parent glycolipid components therefore show component band distributions comparable to one another in being governed by similar ceramide constitutions.     

Structure of the human erythrocyte blood group P1 glycosphingolipid.

A glycosphingolipid with blood group P1 activity was extracted from an acetone powder of human erythrocyte stroma with chloroform-methanol. It was purified by chromatography on columns of silicic acid and by preparative thin-layer chromatography of the fully acetylated and deacetylated glycolipid. The purified glycolipid contained galactose, N-acetylglucosamine, and glucose in a molar ratio of 3:1:1. Treatment of the P1 glycolipid with fig alpha-galactosidase released a single galactosyl residue and destroyed the blood group activity, and the alpha-galactosidase product had the same chromatographic mobility as paragloboside. Substitution sites on the neutral sugars of the P1 glycolipid and the alpha-galactosidase product were established by identification of methylated alditol acetates, and substitution on N-acetylglucosamine was determined by identification of methyl glycoside derivatives. The terminal nonreducing disaccharide of the P1 glycolipid is Gal(alpha, 1 leads to 4)Gal. N-Acetylglucosamine was identified as the next sugar in sequence by mass spectrometric analysis of the permethylated P1 glycolipid. On the assumption that the glucose residue is linked to ceramide, we propose the following structure for the P1 glycolipid: Gal(alpha, 1 leads to 4)Gal(beta, 1 leads to 4)Glc-NAc(beta, 1 leads to 4)Glc-Cer.     

Molecular analysis of a novel family of complex glycoinositolphosphoryl ceramides from Cryptococcus neoformans: structural differences between encapsulated and acapsular yeast forms

Complex glycoinositolphosphoryl ceramides (GIPCs) have been purified from a pathogenic encapsulated wild-type (WT) strain of Cryptococcus neoformans var. neoformans and from an acapsular mutant (Cap67). The structures of the GIPCs were determined by a combination of tandem mass spectrometry, nuclear magnetic resonance spectroscopy, methylation analysis, gas chromatography-mass spectrometry, and chemical degradation. The main GIPC from the WT strain had the structure Manp(alpha1-3)[Xylp(beta1-2)] Manp(alpha1-4)Galp(beta1-6)Manp(alpha1-2)Ins-1-phosphoryl ceramide (GIPC A), whereas the compounds from the acapsular mutant were more heterogeneous in their glycan chains, and variants with Manp(alpha1-6) (GIPC B), Manp(alpha1-6) Manp(alpha1-6) (GIPC C), and Manp(alpha1-2)Manp(alpha1-6)Manp(alpha1-6) (GIPC D) substituents linked to the nonreducing terminal mannose residue found in the WT GIPC A were abundant. The ceramide moieties of C. neoformans GIPCs were composed of a C(18) phytosphingosine long-chain base mainly N-acylated with 2-hydroxy-tetracosanoic acid in the WT GIPC while in the acapsular Cap67 mutant GIPCs, as well as 2-hydroxy-tetracosanoic acid, the unusual 2,3-dihydroxy-tetracosanoic acid was characterized. In addition, structural analysis revealed that the amount of GIPC in the WT cells was fourfold less of that in the acapsular mutant.     

A novel difucosylated neutral glycosphingolipid from the eggs of the sea urchin, Hemicentrotus pulcherrimus: I. Purification and structural determination of the glycolipid.

A novel fucose-containing neutral glycosphingolipid (GL-5) was purified from the eggs of the sea urchin, Hemicentrotus pulcherrimus. The chemical structure was determined to be Fuc alpha 1-3GalNAc beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-4Glc beta 1-1Cer by methylation analysis, partial acid hydrolysis, fast atom bombardment mass spectrometry, and proton nuclear magnetic resonance spectroscopy. The unique characteristics of GL-5 are that: the reducing terminal disaccharide portion is not Gal beta 1-4Glc but GlcNAc beta 1-4Glc; it includes a GalNAc beta 1-4GlcNAc sequence and a Fuc-GalNAc linkage; the defucosylated core is a novel trisaccharide chain; and the sugar structure is one of the smallest ever characterized for a difucosylated glycolipid. The major fatty acids were 22:1 and 22h:1, and about 30% of the total acids was 2-hydroxylated. All the long-chain bases were phytosphingosines, of which about 90% was n-t18:0. The similarity of the ceramide moiety to that of glucosylceramide from the same eggs [Kubo, H. et al. (1992) J. Biochem. 111, 726-731] suggests a close biosynthetic relationship between GL-5 and the glucosylceramide.     

Characterization of the lacto series of gangliosides, especially of disialo-lacto-N-norhexaosyl ceramide isolated from adult bovine nasal cartilage

A disialosylganglioside was isolated from adult bovine nasal cartilage, and its structure was determined by analysis of sugar composition, permethylation analysis, exoglycosidase treatment, and mild acid hydrolysis. The structure of this ganglioside was identified as disialo-lacto-N-norhexaosyl ceramide, NeuNAc(alpha 2-8)NeuNAc-(alpha 2-3)Gal(beta 1-4)GlcNAc(beta 1-3)Gal(beta 1-4)GlcNAc(beta 1-3)Gal(1-4)Glc(1-1)Cer. Furthermore, we also isolated from this cartilage gangliosides whose structures were presumed to be monosialo-lacto-N-norhexaosyl ceramide, and mono- and disialo-lacto-N-neotetraosyl ceramide. The major fatty acids of the four gangliosides isolated were palmitic, stearic, behenic and lignoceric acids. The predominant long chain bases were sphingenine, heptadecasphingenine and hexadecasphingenine.     

Neutral glycosphingolipids of ova of the fresh-water bivalve, Hyriopsis schlegelii

The neutral glycosphingolipids of ova of the fresh-water bivalve, Hyriopsis schlegelii were characterized. The most abundant glycolipid was ceramide monosaccharide, followed by ceramide trisaccharide, ceramide tetrasaccharide, and ceramide disaccharide. More complex neutral glycolipids accounted for almost one-third of the total. The total amount of these glycolipids was 0.59 mg/g of dry weight of the ova preparation, a yield which was one-seventh of that of spermatozoa neutral glycolipids. Structural analyses were performed by enzymatic hydrolysis of the glycolipids with exoglycosidases, permethylation experiments, and also immuno-chemical assays. The proposed structures are as follows: ceramide monosaccharides, Gal-Cer and Glc-Cer; ceramide disacharides, Gal(beta 1-4)Gal-Cer, Gal(beta 1-4)Glc-Cer, and Man(beta 1-4)Glc-Cer; ceramide trisaccharide, Man(alpha 1-3)Man(beta 1-4)Glc-Cer; ceramide tetrasaccharides, Man(alpha 1-3)[Xyl(beta 1-2)]Man(beta 1-4)Glc-Cer, GlcNAc(beta 1-2)Man(alpha 1-3)Man(beta 1-4)Glc-Cer, Man(alpha 1-3)[Gal(beta 1-2)]Man(beta 1-4)Glc-Cer, and Man(alpha 1-2?)Man(alpha 1-3)Man(beta 1-4)Glc-Cer. The latter two ceramide tetrasaccharides were new types of glycosphingolipids. The spectrum of ova glycolipids appeared to be more complicated than that of the spermatozoa glycolipids. The ova glycolipids characterized here, with the exception of ceramide tetrasaccharides, contained considerable amounts of 2-hydroxy fatty acids, which were not observed in the spermatozoa glycolipids. The major sphingosine base was C18-sphingenine in all the ova glycolipids as well as in the spermatozoa glycolipids. However, the content of anteiso type of sphingosine base was 2- to 3-fold higher in the ova than in the spermatozoa.     

The isolation and partial characterization of glycolipids of normal human leucocytes

1. The lipids of purified human leucocytes were extracted with chloroform-methanol and the extract was washed with water. Glycolipids, isolated by Florisil chromatography, were subjected to mild alkaline hydrolysis and the alkali-resistant fraction was fractionated on a silicic acid column. 2. Three classes of glycolipid were separated. The less polar, containing 3.6% of the total glycolipid hexose as galactose, was tentatively identified as ceramide monohexoside. The major glycolipid fraction was characterized as ceramide dihexosides. The more polar glycolipids comprised 1.6% of the total glycolipid hexose as galactose and glucose (in the molar ratio 2:1) and were non-acidic. This class was separated as a mixture containing ninhydrin-positive glycolipids. 3. The ceramide dihexosides taken from two leucocyte preparations accounted for 15.2% and 16.4% by weight of the total lipids. 4. The carbohydrate moiety of the ceramide dihexosides contained galactose and glucose in the molar ratio 2:1. Partial acid hydrolysis and paper chromatography indicated that the hexoses are present as disaccharides, lactose being identified as one of them. 5. Palmitic acid (C(16:0)) and nervonic acid (C(24:1)) were the major fatty acids of this glycolipid. Hydroxy fatty acids were not detected.     

Polar glycosphingolipids in insect: chemical structures of glycosphingolipid series containing 2'-aminoethylphosphoryl-(----6)-N-acetylglucosamine as a polar group from larvae of the green-bottle fly, Lucilia caesar.

A series of glycosphingolipids containing 2'-aminoethylphosphoryl(----6)-N-acetylglucosamine as a polar group has been demonstrated in larvae of the green-bottle fly, Lucilia caesar. The thin-layer chromatographic pattern of the total polar glycolipid revealed the presence of more than eight components, of which five major components were purified by the use of successive column chromatography on QAE- and DEAE-Sephadex and silicic acid (Iatrobeads). From structural studies including compositional sugar analysis, hydrogen fluoride degradation, proton magnetic resonance spectroscopy, methylation analysis, and fast atom bombardment mass spectrometry, their structures were deduced to be as follows: 2'-aminoethylphosphoryl----6GlcNAc beta 1-3Man beta 1-4Glc beta 1-Cer, GalNAc beta 1-4(2'-aminoethylphosphoryl----6)GlcNAc beta 1-3Man beta 1-4Glc beta 1-Cer, GalNAc alpha 1-4GalNAc beta 1-4(2'-aminoethylphosphoryl----6)GlcNAc beta 1-3Man beta 1-4Glc beta 1-Cer, Gal beta 1-3GalNAc alpha 1-4GalNAc-beta 1-4(2'-aminoethylphosphoryl----6)GlcNAc beta 1-3Man beta 1-4Glc beta 1-Cer, and GlcNAc beta 1-3Gal-beta 1-3GalNAc alpha 1-4GalNAc beta 1-4 (2'-aminoethylphosphoryl----6)GlcNAc beta 1-3Man beta 1-4Glc-beta 1-Cer. The main molecular species of the ceramide moiety was arachidinyltetradecasphingenine in all of the major glycolipids.     

Biosynthesis of the cancer-associated sialyl-Lea antigen

A cancer-associated glycolipid antigen defined by monoclonal antibody 19-9 has the structure NeuAc alpha 2-3Gal Gal beta 1-3GlcNAc beta 1-3Gal beta 1-4Glc beta 1-Cer. We have (formula; see text) studied its biosynthesis by testing the capacity of a crude microsomal fraction of SW 1116 cells to catalyze the addition of fucosyl or sialyl residues from GDP-fucose or CMP-sialic acid to glycolipid or oligosaccharide precursors. When the tetrasaccharide NeuAc alpha 2-3Gal beta 1-3GlcNAc beta 1-3Gal beta 1-4Glc (LSTa) is incubated with GDP-[14C]fucose and SW 1116 microsomes, a 14C-labeled oligosaccharide is formed that can be separated from the incubation mixture on an affinity column containing antibody 19-9 bound to protein A-Sepharose. The product migrates slower than LSTa when analyzed by paper or thin-layer chromatography. After treatment with neuraminidase, it co-migrates with the pentasaccharide Gal beta 1-3GlcNAc beta 1-3Gal beta 1-4Glc (formula; see text) (LNF II) in both chromatographic systems. Similar experiments demonstrate that SW 1116 microsomes catalyze the addition of a sialyl residue to the tetrasaccharide Gal beta 1-3GlcNAc beta 1-3Gal beta 1-4Glc to form LSTa. However, when LNF II is incubated with CMP-[14C]sialic acid and SW 1116 microsomes, no 19-9-active product is detected by affinity chromatography or by paper or thin-layer chromatography. Results using glycolipid precursors are consistent with these findings and also demonstrate the presence of the Lewis fucosyltransferase in SW 1116 cells. Thus, the biosynthesis of the sialyl-Lea antigen proceeds by addition of sialic acid to a type 1 precursor chain by a sialyltransferase, followed by addition of fucose by the Lewis fucosyltransferase.     

Structural study of phosphomannan of yeast-form cells of Candida albicans J-1012 strain with special reference to application of mild acetolysis

Structural analysis of the phosphomannan isolated from yeast-form cells of a pathogenic yeast, Candida albicans J-1012 strain, was conducted. Treatment of this phosphomannan (Fr. J) with 10 mM HCl at 100 degrees C for 60 min gave a mixture of beta-1,2-linked manno-oligosaccharides, from tetraose to biose plus mannose, and an acid-stable mannan moiety (Fr. J-a), which was then acetolyzed by means of an acetolysis medium, 100:100:1 (v/v) mixture of (CH3CO)2O, CH3COOH, and H2SO4, at 40 degrees C for 36 h in order to avoid cleavage of the beta-1,2 linkage. The resultant manno-oligosaccharide mixture was fractionated on a column of Bio-Gel P-2 to yield insufficiently resolved manno-oligosaccharide fractions higher than pentaose and lower manno-oligosaccharides ranging from tetraose to biose plus mannose. The higher manno-oligosaccharide fraction was then digested with the Arthrobacter GJM-1 alpha-mannosidase in order to cleave the enzyme-susceptible alpha-1,2 and alpha-1,3 linkages, leaving manno-oligosaccharides containing the beta-1,2 linkage at their nonreducing terminal sites, Manp beta 1----2Manp alpha 1----2Manp alpha 1----2Manp alpha 1----2Man, Manp beta 1----2Manp beta 1----2Manp alpha 1----2Manp alpha 1---- 2Manp alpha 1----2Man, and Manp beta 1----2Manp beta 1----2Manp beta 1----2Manp alpha 1---- 2Manp alpha 1----2Manp alpha 1----2Man. However, the result of acetolysis of Fr. J-a by means of a 10:10:1 (v/v) mixture of (CH3CO)2O, CH3COOH, and H2SO4 at 40 degrees C for 13 h was significantly different from that obtained by the mild acetolysis method; i.e., the amount of mannose was apparently larger than that formed by the mild acetolysis method. In summary, a chemical structure for Fr. J as a highly branched mannan containing 14 different branching moieties was proposed.     

Characterization of major glycolipids in bovine erythrocyte membrane

Several neutral glycolipids and gangliosides were isolated from bovine erythrocyte stroma. Their structures were determined by partial acid hydrolysis, methylation analysis, periodate oxidation and CrO3 oxidation. Two major neutral glycolipids were characterized as lactosylceramide and galactosyl(alpha1--3)galactosyl(beta1--4)N-acetylglucosaminyl(beta1--3)galactosyl(beta1--4)glucosyl(beta1--1)ceramide. Two major gangliosides were N-glycolylneuraminosyl(2--3)galactosyl(beta1--4)glucosyl(beta1--1)ceramide and N-glycolylneuraminosyl(2--3)galactosyl(beta1--4)N-acetylglucosaminyl(beta1--3)galactosyl(beta1--4)glucosyl(beta1--1)ceramide. Minor glycolipids were glucosyl- and galactosylceramide, glucosamine-containing tri- and tetraglycosylceramide, glucosamine-containing disialosylhexaglycosylceramide, and gangliosides containing N-acetylneuraminic acid. The ceramide moiety of each glycolipid contained perdominantly d18:1 sphingosine, and normal fatty acids of C16:0, C22:0, C24:0, and C24:1.     

Biosynthesis of Lewis fucolipid antigens in human colorectal carcinoma cells. Partial characterization of LcOse4Cer and H-1 fucolipid fucosyl transferase acceptor activities

Purified glycolipids were tested for their ability to serve as acceptors of [14C]fucose from GDP-[14C]fucose as catalyzed by cell-free extracts and purified membrane fractions of human colorectal carcinoma cells, SW1116, cultured in serum-free medium. Purified lactotetraosyl ceramide (Gal beta 1----3GlcNAc beta 1----3Gal beta 1----4Glc-Cer or LcOse4Cer) and H-1 glycolipid (Fuc alpha 1----2Gal beta 1----3GlcNAc beta 1----3Gal beta 1----4Glc-Cer or IV2 Fuc alpha LcOse4Cer) stimulated incorporation of radioactivity into lipid-soluble glycolipid at a rate greater than ten times that of Lea glycolipid [Gal beta 1----3(Fuc alpha 1----4)GlcNAc beta 1----3Gal beta 1----4Glc-Cer or III4 Fuc alpha LcOse4Cer]. The enzymatic activities in crude and purified membrane fractions were optimized for substrate concentrations (glycolipid and GDP-fucose), detergent requirement (taurocholate), pH, time and protein. The radioactive product of H-1 fucosylation migrated as discrete and distinct bands on high-performance thin-layer chromatograms (HPTLC). Evidence for their identity with Leb fucolipid described previously [Fuc alpha 1----2Gal beta 1----3(Fuc alpha 1----4)GlcNAc beta 1----3Gal beta 1----4Glc-Cer or III4IV2 (Fuc alpha) LcOse4Cer] is presented. The radioactive product of LcOse4Cer fucosylation was mainly Lea fucolipid as determined by co-migration with authentic Lea fucolipid in three HPTLC systems as native and acetylated derivatives. Our results also indicated a low level of H-1 and Leb glycolipid synthesis from LcOse4Cer. On the basis of the optima, linearity for time, and enzyme-limiting conditions, we obtained a 12-19-fold purification of the LcOse4Cer and H-1 fucosyl transferase acceptor activities in three peaks of a sucrose gradient. The peak with the highest specific activity (peak 3) was highest in density and in Na+, K+, ATPase specific activity, although NADH-cytochrome-c reductase and UDP-GalNac transferase were also present in peak 3. The apparent Km values of LcOse4Cer acceptor activity and H-1 acceptor activity in peak 3 were significantly different (p less than 0.01) by statistical tests, 2.4 microM and 0.5 microM, respectively. These apparent Km values were much lower (10(3) X) and the pH optima were lower (4.8-5.3), than the corresponding properties reported for the alpha 1----3/alpha 1----4 fucosyl transferase purified from human milk. Our results suggest a role for the non-glycosidic moieties of the acceptors and/or the tissue-specific or primitive expression of these fucosyl transferase activities.     

Detection of bisected biantennary form in the asparagine-linked oligosaccharides of fibronectin isolated from human term amniotic fluid

Fibronectin purified from human term amniotic fluid contains 10 asparagine-linked sugar chains in one molecule. The sugar chains were quantitatively liberated as radioactive oligosaccharides from the polypeptide moiety by hydrazinolysis followed by N-acetylation and NaB3H4 reduction and fractionated by anion-exchange column chromatography and serial lectin affinity chromatography. The structures of these sugar chains were determined by sequential exoglycosidase digestion in combination with methylation analysis. The results indicated that they are a mixture of bisected and non-bisected bi- and triantennary complex-type sugar chains with and without a fucose on the proximal N-acetylglucosamine residue and with Gal beta 1----4GlcNAc beta 1----, GlcNAc beta 1----, Neu5Ac alpha 2----3Gal beta 1----4GlcNAc beta 1----, and Neu5Ac alpha 2----6Gal beta 1----4GlcNAc beta 1---- groups in their outer chain moieties.     

Glycosphingolipids of porcine pancreas

Neutral and acidic glycosphingolipids were purified from porcine pancreas by chromatography on columns of DEAE-Sephadex and Iatrobeads. The chemical structures of the purified glycolipids were determined by carbohydrate analysis, methylation analysis, enzyme treatment, fatty acid analysis, NMR and IR. The major glycolipid of porcine pancreas was Gal(alpha,1-4)Gal(beta,1-)ceramide. Gangliosides GM3 and GD3 were major acidic components and galactosylceramide 3-sulfate was also found.     

Structural studies on glycolipid of shellfish. III. Novel glycolipids from Turbo cornutus

Five kinds of sphingoglycolipids were isolated from Turbo cornutus. Four of them were a series of novel glycolipids consisting only of galactose. The structures of these glycolipids were studied by methylation analysis, periodate oxidation, enzymatic degradation, and proton magnetic resonance spectroscopy. Three glycolipids were characterized as galactosyl(beta 1 leads to 1)ceramide, galactosyl(beta 1 leads to 6)galactosyl(beta 1 leads to 1)ceramide, and galactosyl(beta 1 leads to 6)galactosyl(beta 1 leads to 6)galactosyl(beta 1 leads to 1)ceramide. Data indicating that the 4th glycolipid might be the tetragalactosyl derivative of this series were obtained. The carbohydrate moiety of the 5th glycolipid, in contrast, was composed of fucose, galactose, glucose and N-acetylglycosamine in a molar ratio of 1 : 2 : 1 : 1.     

An antigen present in rat adenocarcinoma and normal colon non-epithelial stroma is a novel Forssman-like glycolipid based on isoglobotetraosylceramide

A glycolipid with blood group A activity detected in the non-epithelial stroma of normal rat colon but not in epithelial cells (Hansson, G.C., Karlsson, K.-A., and Thurin, J. (1984) Biochim. Biophys. Acta 792, 281-292), was purified to homogeneity from normal rat colon and rat colon adenocarcinoma. Mass spectrometry and 1H-NMR spectroscopy of the intact permethylated derivative and gas chromatography after degradation revealed the structure GalNAc alpha 1----3GAINAc beta 1----3Gal alpha 1----3Gal beta 1----4Glc beta 1----1Cer, with the predominant ceramide containing sphingosine and non-hydroxylated 24:0 fatty acid. This identifies this glycolipid as a novel Forssman-like glycolipid, which is a tumor-associated antigen by definition, since it is not present in the normal rat large intestinal epithelium cells but in rat adenocarcinoma derived from these cells.     

Structural characterization of lactotetraosylceramide, a novel glycosphingolipid isolated from human meconium.

In the course of work on a systematic structural mapping of nonacid glycosphingolipids of human meconia, special attention was given to a major component preliminarily identified as an isomer of neolactotetraosylceramide (paragloboside). This component was isolated in its pure form from meconium of a blood group O individual and subjected to detailed structural analyses, using mass spectrometry and proton NMR spectroscopy on intact permethylated and permethylated-reduced (LiAlH4) derivatives, and gas liquid chromatography on degradational products of native, permethylated, and permethylated-reduced derivatives. The isolated compound was conclusively shown to have the structure Galp beta 1 yields 3GlcNAcp beta 1 yields 3Galp beta 1 yields 4Glcp beta 1 yields 1Cer, and is thus identified as lactotetraosylceramide. The major fatty acids were 2-hydroxy fatty acids with 16 and 20 to 24 carbon atoms, and the bases were sphingosine and phytosphingosine. This glycolipid, although not isolated and structurally characterized before, has long been thought of as a precursor substance of the Lewis active glycolipids and of ABH-active glycolipids with a type 1 saccharide chain.