| 1. |
- Blacher, E., et al.
(författare)
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Potential roles of gut microbiome and metabolites in modulating ALS in mice
- 2019
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 572:7770
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Tidskriftsartikel (refereegranskat)abstract
- Amyotrophic lateral sclerosis (ALS) is a complex neurodegenerative disorder, in which the clinical manifestations may be influenced by genetic and unknown environmental factors. Here we show that ALS-prone Sod1 transgenic (Sod1-Tg) mice have a pre-symptomatic, vivarium-dependent dysbiosis and altered metabolite configuration, coupled with an exacerbated disease under germ-free conditions or after treatment with broad-spectrum antibiotics. We correlate eleven distinct commensal bacteria at our vivarium with the severity of ALS in mice, and by their individual supplementation into antibiotic-treated Sod1-Tg mice we demonstrate that Akkermansia muciniphila (AM) ameliorates whereas Ruminococcus torques and Parabacteroides distasonis exacerbate the symptoms of ALS. Furthermore, Sod1-Tg mice that are administered AM are found to accumulate AM-associated nicotinamide in the central nervous system, and systemic supplementation of nicotinamide improves motor symptoms and gene expression patterns in the spinal cord of Sod1-Tg mice. In humans, we identify distinct microbiome and metabolite configurations-including reduced levels of nicotinamide systemically and in the cerebrospinal fluid-in a small preliminary study that compares patients with ALS with household controls. We suggest that environmentally driven microbiome-brain interactions may modulate ALS in mice, and we call for similar investigations in the human form of the disease.
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| 2. |
- Bock, K, et al.
(författare)
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Specificity of binding of a strain of uropathogenic Escherichia coli to Gal alpha 1----4Gal-containing glycosphingolipids.
- 1985
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Ingår i: The Journal of biological chemistry. - 0021-9258. ; 260:14, s. 8545-51
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Tidskriftsartikel (refereegranskat)abstract
- A strain of Escherichia coli originally isolated from urine of a patient with acute pyelonephritis was studied in detail for binding to glycosphingolipids. Bacteria labeled metabolically with [14C]glucose were layered over a glycolipid chromatogram and bound bacteria were detected by autoradiography. The detection was down to a few ng of glycolipid (pmol level) under these assay conditions. At a test level of 500 ng all glycolipids (more than a dozen molecular species analyzed) with Gal alpha 1----4Gal as an internal or terminal part bound the bacteria strongly while glycolipids known to lack this sequence were negative. Conformational analysis using hard sphere calculations including the exo-anomeric effect showed a bend in the saccharide chain at this disaccharide with a largely hydrophobic surface of the convex side, probably being part of the binding epitope. Mixtures of glycolipids isolated from a human ureter scraping and from urinary sediments bound bacteria in the 2- to 7-sugar interval. Thus, this infectious strain of E. coli recognizes glycolipids being present in epithelial cells lining the urinary tract.
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| 3. |
- Hickey, C. A., et al.
(författare)
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Colitogenic Bacteroides thetaiotaomicron Antigens Access Host Immune Cells in a Sulfatase-Dependent Manner via Outer Membrane Vesicles
- 2015
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Ingår i: Cell Host & Microbe. - : Elsevier BV. - 1931-3128. ; 17:5, s. 672-680
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Tidskriftsartikel (refereegranskat)abstract
- Microbes interact with the host immune system via several potential mechanisms. One essential step for each mechanismis themethod by which intestinal microbes or their antigens access specific host immune cells. Using genetically susceptible mice (dnKO) that develop spontaneous, fulminant colitis, triggered by Bacteroides thetaiotaomicron (B. theta), we investigated the mechanism of intestinal microbial access under conditions that stimulate colonic inflammation. B. theta antigens localized to host immune cells through outer membrane vesicles (OMVs) that harbor bacterial sulfatase activity. We deleted the anaerobic sulfatase maturating enzyme (anSME) from B. theta, which is required for post-translational activation of all B. theta sulfatase enzymes. This bacterial mutant strain did not stimulate colitis in dnKO mice. Lastly, access of B. theta OMVs to host immune cells was sulfatase dependent. These data demonstrate that bacterial OMVs and associated enzymes promote inflammatoryimmune stimulation in genetically susceptible hosts.
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| 4. |
- Schütte, André, et al.
(författare)
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Microbial-induced meprin β cleavage in MUC2 mucin and a functional CFTR channel are required to release anchored small intestinal mucus
- 2014
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 111:34, s. 12396-12401
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Tidskriftsartikel (refereegranskat)abstract
- The mucus that covers and protects the epithelium of the intestine is built around its major structural component, the gel-forming MUC2 mucin. The gel-forming mucins have traditionally been assumed to be secreted as nonattached. The colon has a two-layered mucus system where the inner mucus is attached to the epithelium, whereas the small intestine normally has a nonattached mucus. However, the mucus of the small intestine of meprin β-deficient mice was now found to be attached. Meprin β is an endogenous zinc-dependent metalloprotease now shown to cleave the N-terminal region of the MUC2 mucin at two specific sites. When recombinant meprin β was added to the attached mucus of meprin β-deficient mice, the mucus was detached from the epithelium. Similar to meprin β-deficient mice, germ-free mice have attached mucus as they did not shed the membrane-anchored meprin β into the luminal mucus. The ileal mucus of cystic fibrosis (CF) mice with a nonfunctional cystic fibrosis transmembrane conductance regulator (CFTR) channel was recently shown to be attached to the epithelium. Addition of recombinant meprin β to CF mucus did not release the mucus, but further addition of bicarbonate rendered the CF mucus normal, suggesting that MUC2 unfolding exposed the meprin β cleavage sites. Mucus is thus secreted attached to the goblet cells and requires an enzyme, meprin β in the small intestine, to be detached and released into the intestinal lumen. This process regulates mucus properties, can be triggered by bacterial contact, and is nonfunctional in CF due to poor mucin unfolding.
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| 5. |
- Sheikh, A., et al.
(författare)
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Enterotoxigenic Escherichia coli Degrades the Host MUC2 Mucin Barrier To Facilitate Critical Pathogen-Enterocyte Interactions in Human Small Intestine
- 2022
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Ingår i: Infection and Immunity. - : American Society for Microbiology. - 0019-9567 .- 1098-5522. ; 90:2
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Tidskriftsartikel (refereegranskat)abstract
- Enterotoxigenic Escherichia coli (ETEC) isolates are genetically diverse pathological variants of E. coli defined by the production of heat-labile (LT) and/or heat-stable (ST) toxins. ETEC strains are estimated to cause hundreds of millions of cases of diarrheal illness annually. However, it is not clear that all strains are equally equipped to cause disease, and asymptomatic colonization with ETEC is common in low- to middle-income regions lacking basic sanitation and clean water where ETEC are ubiquitous. Recent molecular epidemiology studies have revealed a significant association between strains that produce EatA, a secreted autotransporter protein, and the development of symptomatic infection. Here, we demonstrate that LT stimulates production of MUC2 mucin by goblet cells in human small intestine, enhancing the protective barrier between pathogens and enterocytes. In contrast, using explants of human small intestine as well as small intestinal enteroids, we show that EatA counters this host defense by engaging and degrading the MUC2 mucin barrier to promote bacterial access to target enterocytes and ultimately toxin delivery, suggesting that EatA plays a crucial role in the molecular pathogenesis of ETEC. These findings may inform novel approaches to prevention of acute diarrheal illness as well as the sequelae associated with ETEC and other pathogens that rely on EatA and similar proteases for efficient interaction with their human hosts. © 2022 American Society for Microbiology. All rights reserved.
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| 6. |
- Axelsson, Magnus A. B., et al.
(författare)
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Deglycosylation by gaseous hydrogen fluoride of mucus glycoproteins immobilized on nylon membranes and in microtiter wells.
- 1998
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Ingår i: Glycoconjugate journal. - 0282-0080. ; 15:8, s. 749-55
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Tidskriftsartikel (refereegranskat)abstract
- Strongly reacting antibodies specific for defined mucin gene products are often directed against the mucin protein backbone of the heavily glycosylated serine/threonine rich regions. A prerequisite for the use of such antibodies is often the complete removal of the oligosaccharides from the protein. This paper describes an efficient one-step deglycosylation method using gaseous hydrogen fluoride on nylon blotting membranes and microtiter wells.
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| 7. |
- Baker, N, et al.
(författare)
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Glycosphingolipid receptors for Pseudomonas aeruginosa.
- 1990
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Ingår i: Infection and immunity. - 0019-9567. ; 58:7, s. 2361-6
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Tidskriftsartikel (refereegranskat)abstract
- The binding of Pseudomonas aeruginosa to glycosphingolipids and to buccal and bronchial epithelial cells was analyzed. Three independently expressed specificities were found by bacterial binding to glycosphingolipids separated by thin-layer chromatography. All strains bound gangliotria- and gangliotetrasylceramide. All but one of the strains bound sialic acid-containing glycosphingolipids and lactosylceramide. The latter two specificities could be separated in that the lactosylceramide binding was retained and the sialic acid binding was suppressed when bovine serum albumin was used as a blocking agent in the thin-layer chromatography assay. The attachment to buccal epithelial cells, like the binding to sialylated compounds and lactosylceramide, was abolished by Formalin treatment of the bacteria, suggesting the importance of these specificities for cell adherence. In contrast, the binding to gangliotria- and gangliotetraosylceramide was retained by nonattaching Formalin-treated bacteria.
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| 8. |
- Birchenough, George M. H., et al.
(författare)
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Muc2-dependent microbial colonization of the jejunal mucus layer is diet sensitive and confers local resistance to enteric pathogen infection
- 2023
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Ingår i: Cell Reports. - Cambridge : Elsevier BV. - 2211-1247. ; 42:2
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Tidskriftsartikel (refereegranskat)abstract
- Intestinal mucus barriers normally prevent microbial infections but are sensitive to diet-dependent changes in the luminal environment. Here we demonstrate that mice fed a Western-style diet (WSD) suffer regiospe-cific failure of the mucus barrier in the small intestinal jejunum caused by diet-induced mucus aggregation. Mucus barrier disruption due to either WSD exposure or chromosomal Muc2 deletion results in collapse of the commensal jejunal microbiota, which in turn sensitizes mice to atypical jejunal colonization by the enteric pathogen Citrobacter rodentium. We illustrate the jejunal mucus layer as a microbial habitat, and link the re-giospecific mucus dependency of the microbiota to distinctive properties of the jejunal niche. Together, our data demonstrate a symbiotic mucus-microbiota relationship that normally prevents jejunal pathogen colo-nization, but is highly sensitive to disruption by exposure to a WSD.
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| 9. |
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| 10. |
- Björk, S, et al.
(författare)
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Structures of blood group glycosphingolipids of human small intestine. A relation between the expression of fucolipids of epithelial cells and the ABO, Le and Se phenotype of the donor.
- 1987
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Ingår i: The Journal of biological chemistry. - 0021-9258. ; 262:14, s. 6758-65
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Tidskriftsartikel (refereegranskat)abstract
- Small intestinal epithelial cells (enterocytes) were isolated from specimens obtained at operation from four human individuals with different blood group ABO, Lewis, and secretor phenotypes. The non-acid glycolipids were isolated and characterized by thin-layer chromatography, mass spectrometry, and proton NMR spectroscopy and for reactivity with monoclonal antibodies on thin-layer chromatograms. Monohexosylceramides and blood group ABH (type 1 chain) and Lewis glycolipids with 5-7 sugar residues were the major compounds present in all cases, and the expression of the major blood group glycolipids was in agreement with the ABO, Lewis, and secretor phenotype of the individual donors. Small amounts of more complex glycolipids with up to 10 sugar residues were identified by mass spectrometry in all cases. In addition, small amounts of lactotetraosylceramide, a blood group H-active triglycosylceramide with the structure of Fuc alpha 1-2Gal-Hex-Cer (where Fuc is fucose, Hex is hexose, and Cer is ceramide), and dihexosylceramides were identified in some cases. Globotriaosyl- and globotetraosylceramides were absent from the epithelial cells. Small amounts of Leb-active glycolipids in blood group OLe(a+b-), non-secretor and OLe(a-b-), secretor individuals as well as trace amounts of type 2 carbohydrate chain compounds in all individuals were detected by specific monoclonal antibodies.
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| 11. |
- Bosmans, J W A M, et al.
(författare)
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Functional mucous layer and healing of proximal colonic anastomoses in an experimental model.
- 2017
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Ingår i: The British journal of surgery. - : Oxford University Press (OUP). - 1365-2168 .- 0007-1323. ; 104:5, s. 619-630
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Tidskriftsartikel (refereegranskat)abstract
- Anastomotic leakage (AL) is the most dreaded complication after colorectal surgery, causing high morbidity and mortality. Mucus is a first line of defence against external factors in the gastrointestinal tract. In this study, the structural mucus protein Muc2 was depleted in genetically engineered mice and the effect on healing of colonic anastomoses studied in an experimental model.Mice of different Muc2 genotypes were used in a proximal colonic AL model. Tissues were scored histologically for inflammation, bacterial translocation was determined by quantitative PCR of bacterial 16S ribosomal DNA, and epithelial cell damage was determined by assessing serum levels of intestinal fatty acid-binding protein.Of 22 Muc2-deficient (Muc2(-/-) ) mice, 20 developed AL, compared with seven of 22 control animals (P <0·001). Control mice showed normal healing, whereas Muc2(-/-) mice had more inflammation with less collagen deposition and neoangiogenesis. A tendency towards higher bacterial translocation was seen in mesenteric lymph nodes and spleen in Muc2(-/-) mice. Intestinal fatty acid-binding protein levels were significantly higher in Muc2(-/-) mice compared with controls (P = 0·011).A functional mucous layer facilitates the healing of colonic anastomoses. Clinical relevance Colorectal anastomotic leakage remains the most dreaded complication after colorectal surgery. It is known that the aetiology of anastomotic leakage is multifactorial, and a role is suggested for the interaction between intraluminal content and mucosa. In this murine model of proximal colonic anastomotic leakage, the authors investigated the mucous layer at the intestinal mucosa, as the first line of defence, and found that a normal, functioning mucous layer is essential in the healing process of colonic anastomoses. Further research on anastomotic healing should focus on positively influencing the mucous layer to promote better postoperative recovery.
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| 12. |
- Breimer, Michael, 1951, et al.
(författare)
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Blood group glycosphingolipids of human kidney.
- 1983
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Ingår i: Glycoconjugates (eds Chester, A, Heinegård D, Lundblad A, Svensson S).. - Lund : Rham Publ Lund. ; , s. 421-422
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 13. |
- Breimer, Michael, 1951, et al.
(författare)
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Blood group type glycosphingolipids from the small intestine of different animals analysed by mass spectrometry and thin-layer chromatography. A note on species diversity.
- 1981
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Ingår i: Journal of biochemistry. - 0021-924X. ; 90:3, s. 589-609
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Tidskriftsartikel (refereegranskat)abstract
- The total non-acid glycosphingolipids were isolated from the small intestine of cat, cod-fish, guinea-pig, hen, mouse, rabbit, and two strains of rat. The samples were analyzed by thin-layer chromatography and mass spectrometry and for immunological activity. Mass spectrometry of permethylated and LiAlH4-reduced permethylated derivatives allowed the interpretation of the structures (carbohydrate sequence and ceramide composition) of up to 9 glycolipid species in one mixture. The interpretation was facilitated by a temperature programming of the direct inlet probe, leading to a successive evaporation of glycolipid species mainly according to the number of sugars. The structures concluded could in most cases be assigned to the separate bands revealed by thin-layer chromatography. Antigenic determinants proposed by the spectra were settled by immunological analysis. Thus, Forssman glycolipid was identified in cat, guinea-pig, hen and mouse, blood group A glycolipids in cat, rabbit, and rat and blood group B glycolipids in rabbit and rat. No Lewis activity was found. Certain ceramide types were demonstrated to exist preferentially in some glycolipids. Globoside and Forssman glycolipids (globo series) had a less hydroxylated ceramide (one free hydroxyl) compared to most fucolipids and other glycolipids (two or three hydroxyls). In conclusion, glycolipid patterns of intestine vary between species, and individuals of the same species.
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| 14. |
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| 15. |
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| 16. |
- Breimer, Michael, 1951, et al.
(författare)
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Glycolipids of rat small intestine. Characterization of a novel blood group H-active triglycosylceramide.
- 1980
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Ingår i: Biochimica et biophysica acta. - 0006-3002. ; 617:1, s. 85-96
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Tidskriftsartikel (refereegranskat)abstract
- A novel blood group H-active triglycosylceramide has been isolated from rat small intestine. It was present exclusively in the epithelial cells. The structure was established by mass spectrometry, NMR spectroscopy and degradative methods to the Fucp alpha 1 leads to 2Galp beta 1 leads to 4Glcp beta 1 leads to 1Cer. The lipophilic part was made up of mainly trihydroxy base (phytosphingosine) and 16 : 0--24 : 0 fatty acids.
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| 17. |
- Breimer, Michael, 1951, et al.
(författare)
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Glycosphingolipid composition of epithelial cells isolated along the villus axis of small intestine of a single human individual
- 2012
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Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 22:12, s. 1721-1730
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Tidskriftsartikel (refereegranskat)abstract
- A 6-cm fresh proximal ileum surgical specimen from a blood group A(1)Le(a-b+) secretor individual was used for stepwise isolation of epithelial cells from villus tip to crypt bottom by gentle washing with ethylenediaminetetraacetic acid-containing buffer. Acid and non-acid sphingolipids were prepared from the epithelial cell fractions and the non-epithelial intestinal residue. Molecular information on the sphingolipid composition was obtained without further isolation of individual species by applying thin-layer chromatography using chemical and biological (monoclonal antibodies, cholera toxin, Escherichia coli) detection reagents, mass spectrometry and proton NMR spectroscopy of derivatized glycolipids. In this way, the structure of major and minor saccharides, ceramide components and their relative amounts were obtained. Epithelial cells and non-epithelial residue were distinctly different in their sphingolipid composition. Sphingomyelin was the major single component in both compartments. Characteristic for epithelial cells was the dominance of monoglycosylceramides, sulphatides and blood group fucolipids (mainly Le(b) hexaglycosylceramides and ALe(b) heptaglycosylceramides). The non-epithelial residue had about five times less glycolipids mainly mono-, di-, tri- and tetra-glycosylceramides and gangliosides, including the GM1 ganglioside. The ceramides were more hydroxylated (1-2 additional hydroxyls) in epithelial cell glycolipids compared with the non-epithelial residue. Combined with a separate detailed study on the glycoproteins of the same epithelial cell preparation, this human intestinal sample is the only epithelial cell preparation where both protein- and lipid-linked saccharides are characterized in detail.
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| 18. |
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| 19. |
- Breimer, Michael, 1951, et al.
(författare)
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Glycosphingolipids of rat tissues. Different composition of epithelial and nonepithelial cells of small intestine.
- 1982
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Ingår i: The Journal of biological chemistry. - 0021-9258. ; 257:1, s. 557-68
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Tidskriftsartikel (refereegranskat)abstract
- The epithelial cells of rat small intestine (jejunum-ileum) were separated from their supporting stroma (residue). Total nonacid and acid glycosphingolipids were prepared from the two compartments. The acetylated nonacid glycolipids were separated into 10-12 fractions by column chromatography. These were analyzed by chromatographic methods, mass spectrometry, and proton NMR spectroscopy and compared with glycolipids isolated from whole rat small intestine. The sialic acid-containing glycosphingolipids were compared in the same way without subfractionation. At least 37 different glycosphingolipids (different carbohydrate moieties) were found, 23 in the nonepithelial residue and 17 in the epithelial cells of one rat strain. In a second rat strain, another 4 structures were detected. The glycosphingolipids of epithelial cells and nonepithelial residue were distinctly different. Glucosylceramide, lactosylceramide, and globotriaosylceramide were found in both compartments, while isoglobotriaosylceramide was restricted to the nonepithelial residue. A tetrahexosylceramide with a terminal Gal alpha 1 leads to 3 on a globotriaosylceramide core was found in both compartments as were homologues with 1 or 2 additional internal leads to 3Gal alpha 1 leads to units, but homologues with 3 or 4 additional internal Gal were only nonepithelial. Glycosphingolipids with terminal beta-GalNAc were restricted to the nonepithelial residue comprising globotetraosylceramide, isoglobotetraosylceramide, and a series of glycolipids with 5 to 9 sugars having the above-mentioned oligohexosylceramides as core structures. Fucolipids (blood group H) having 3, 5, 6, and 7 sugars and lacking amino sugars, and fucolipids with 5 and 10 sugars containing N-acetylglucosamine were restricted to the epithelial cells. Fucolipids (blood groups H and B) with 5 and 6 sugars containing N-acetylgalactosamine were restricted to the nonepithelial residue. In a 4, 6, and 12 sugars were found in the epithelial cells. N-Glycoloylneuraminosyllactosylceramide was the only ganglioside found in the epithelial cells while N-acetylneuraminosyllactosylceramide was nonepithelial together with gangliosides based on gangliotetraosylceramide and isoglobotetraosylceramide.
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| 20. |
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| 21. |
- Breimer, Michael, 1951, et al.
(författare)
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Isolation and partial characterization of blood group A and H active glycosphingolipids of rat small intestine.
- 1982
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Ingår i: The Journal of biological chemistry. - 0021-9258. ; 257:2, s. 906-12
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Tidskriftsartikel (refereegranskat)abstract
- Blood group A and H active glycosphingolipids have been isolated from rat small intestine. By mass spectrometry of the permethylated and LiAlH4-reduced permethylated glycolipid derivatives, the A glycolipids were shown to contain four (A-4), six (A-6), and 12 (A-12) sugar residues, respectively. The anomeric structure of the A-4 and A-6 glycolipids was established by proton NMR spectroscopy of the permethylated-reduced derivatives. Acid degradation and gas chromatography were used for analysis of binding positions. The structures of the A-4 and A-6 glycolipids were GalNAcp alpha 1 leads to 3Galp(2 comes from 1Fucp alpha) beta 1 leads to Glcp beta 1 leads to 1Cer and GalNAcp alpha 1 leads to 3Galp(2 comes from 1Fucp alpha) beta 1 leads to 3GlcNAcp beta 1 leads to 4Galp beta 1 leads to 4Glcp beta 1 leads to 1Cer. The third glycolipid (A-12) was a branched dodecaglycosylceramide with two blood group A determinants. The complete structure of this glycolipid has not yet been solved. The blood group A activity was the same for the A-6 and A-12 glycolipids based on an equal number of blood group A determinants, but the activity of the A-4 compound was only about half of the others. The A-6 glycolipid was based on a type 1 (Gal beta 1 leads to 3GlcNAc) carbohydrate chain, thus differing from the already known isomer based on a type 2 chain (Gal beta 1 leads to 4GlcNAc) present in human erythrocyte. The blood group A activity of these two glycolipids was found to be identical. The three rat intestinal blood group A active glycolipids were exclusively located to the mucosa epithelial cells. The blood group H active tri- and pentaglycosylceramides (H-3 and H-5), presumed to be the precursors of the A-4 and A-6 glycolipids, were also identified. A 10-sugar glycolipid (H-10), a possible precursor of A-12, was not detected.
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| 22. |
- Breimer, Michael, 1951, et al.
(författare)
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Selected ion monitoring of glycospingolipid mixtures. Identification of several blood group type glycolipids in the small intestine of an individual rabbit.
- 1979
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Ingår i: Biomedical mass spectrometry. - : Wiley. - 0306-042X .- 1096-9888. ; 6:6, s. 231-41
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Tidskriftsartikel (refereegranskat)abstract
- A novel application of selected ion monitoring was used for a mixture of non-acid glycosphingolipids of one rabbit small intestine. Earlier studies of permethylated and permethylated-reduced (LiAIH4) derivatives of model compounds have revealed a specificity and abundance of saccharide ions (terminal monosaccharide(s), disaccharide, trisaccharide, etc., and all sugars plus fatty acid) and of ceramide fragments that permit a conclusive detection of separate glycolipid species in a mixture. The sample (50-200 micrograms) was evaporated slowly (1-5 degrees C min-1 from 150-350 degrees C) from the direct inlet probe of an MS 902 mass spectrometer (electron ionization). Mass spectra with fragments up to about m/z 200 were collected on-line by a computer system. A successive partial separation was obtained for glycolipids with from one up to seven sugars. The structures of eight different compounds were identified. They all had 16:0, 22:0 and 24:0 2-hydroxy fatty acids and 18:0 trihydroxy base (phytosphingosine) as major ceramide components. The dominating complex glycolipid was a hexaglycosylceramide with a blood group B type of sequence. A blood group A type sequence was found in a second hexaglycosylceramide. In support of this, the native mixture showed blood group A and B activity. An intense peak, m/z 182, collected from methylated derivatives were evidence for a dominating type 2 carbohydrate chain of the core tetrasaccharide.
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| 23. |
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| 24. |
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| 25. |
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