Biomedical subjects

T Kasama

Publications and source records attributed to T Kasama.

At least 73 records · Page 4Linked to original sources

PubMed1995

Direct mass spectrometric analysis of glycosphingolipid transferred to a polyvinylidene difluoride membrane by thin-layer chromatography blotting.

A simple, rapid method for the analysis of glycosphingolipid that combines "thin-layer chromatography (TLC) blotting" and mass spectrometry is reported. Glycosphingolipids developed by TLC were transferred to a polyvinylidene difluoride membrane by TLC blotting, after which the glycosphingolipid band on the membrane was excised and placed on a mass spectrometer probe tip, and a few microliters of triethanolamine was added as the matrix. The sample was analyzed by secondary ion mass spectrometry. About 1 microgram of glycosphingolipid subjected to TLC can be analyzed. The major advantage of this method is that glycosphingolipid can be analyzed structurally without purification by repeated column chromatography.

Animals↗

PubMed1995

Accumulation of isogloboside and ganglio-N-tetraosyl ceramide having blood group B determinant in the hepatomas of female LEC rats.

We have studied the neutral glycolipid composition of spontaneous hepatomas in LEC female rats. Neutral lipid fractions were isolated and purified by column chromatographies on DEAE-Toyopearl 650(M) and Iatrobeads. The neutral glycolipid fraction contained 3.2 to 4.4 micrograms lipid-bound glucose (Glc) per mg protein, and consisted of isogloboside (iso-Gb4, 50.8% of total neutral glycolipids) and IV3Gal, IV2Fuc, GgOse4Cer (asialo-BGM1, 13.5%) as the major neutral glycolipids and Gb3 and iso-Gb3 (9.2%), GlcCer (7.2%), LacCer (6.1%) as the other species. The structure of iso-Gb4 was elucidated by gas-liquid chromatography (GLC), permethylation study, liquid secondary ion (LSI) mass spectrometry, and nuclear Overhauser enhancement spectroscopy (NOESY) and that for asialo-BGM1 by GLC, LSI mass spectrometry, and high-performance thin-layer chromatography (HPTLC)-overlay method using anti-asialo-BGM1 antibody. Isogloboside and asialo-BGM1 which are found in negligible amounts in normal liver tissues may represent excellent markers for studying tumor metastasis and cellular adhesion.

ABO Blood-Group System↗

PubMed1995

Effect of eicosapentaenoic acid and docosahexaenoic acid on diabetic osteopenia.

To evaluate the effect of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are polyunsaturated fatty acids, on diabetic osteopenia, we measured the bone fragility in streptozotocin-induced diabetic rats. The fragility of femur was increased in diabetic rats, which was prevented in part by EPA or DHA. Moreover, EPA prevented osteopenia even in diabetic rats fed a low zinc feed, which was a potent accelerator of diabetic osteopenia. Plasma alkaline phosphatase activity and parathyroid hormone level showed no difference between the two groups of diabetic rats with or without EPA. Urinary excretion of calcium and phosphate was increased and plasma inorganic phosphate level was high in diabetic rats, suggesting severe mineral loss. In diabetic rats fed EPA, although urinary and plasma calcium levels did not change significantly, urinary phosphate excretion and plasma inorganic phosphate concentration were slightly lowered, which suggested that EPA may have an effect in suppressing phosphate release from bones in diabetic rats. These data suggest that EPA and DHA could be effective on diabetic osteopenia, but to elucidate the precise mechanisms, further examinations will be needed.

Alkaline Phosphatase↗

PubMed1995

A novel allelic variant of serum amyloid A, SAA1 gamma: genomic evidence, evolution, frequency, and implication as a risk factor for reactive systemic AA-amyloidosis.

Reactive systemic amyloidosis, also called AA-amyloidosis is a rare fatal complication of common chronic inflammatory diseases such as rheumatoid arthritis. It has been proposed that as yet undefined factors other than persistent elevation of serum level of the precursor protein, serum amyloid A (SAA), are also important for the development of AA-amyloidosis. In this work we show genomic evidence for a novel allelic variant of human SAA, SAA1 gamma, which we have recently identified at the protein level. The SAA1 gamma [Ala52(GCC), Ala57(GCG)] differed from SAA1 alpha [Val52(GTC), Ala57(GCG)] only at one base, indicating a single point mutation. On the other hand, SAA1 beta [Ala52(GCC), Val57(GTG)] had not only one, but additional differences in a nearby intron and this portion was identical to the SAA2 gene, suggesting a crossing-over between the SAA1 and SAA2 genes. Furthermore, we report that there was a significant difference in the observed numbers of SAA1 alleles between rheumatoid arthritis patients with AA-amyloidosis and the control population (chi 2(2) = 11.59, p = 0.003) with a higher frequency of gamma-allele in the AA-amyloid group (0.70 vs. 0.37). There was also a notable difference in the distribution of SAA1 genotypes (chi 5(2) = 14.63, p = 0.012) with an increased frequency of gamma/gamma-homozygotes in the AA-amyloid group (0.60 vs. 0.18). Thus our findings indicate that this novel allelic variant may be an important risk factor for the development of AA-amyloidosis.

Adult↗

PubMed1995

Regulation of vitamin D-responsive gene expression by fluorinated analogs of calcitriol in rat osteoblastic ROB-C26 cells.

We compared the activation of vitamin D-responsive genes by 24,24-difluorocalcitriol [F2-1 alpha,25(OH)2D3] and 26,26,26,27,27,27-hexafluorocalcitriol [F6-1 alpha,25(OH)2D3] with that by calcitriol [1 alpha,25(OH)2D3] in rat osteoblastic ROB-C26 cells. F2-1 alpha,25(OH)2D3 and F6-1 alpha, 25(OH)2D3 were ten times more potent than 1 alpha,25(OH)2D3 in inducing the expression of 1 alpha, 25(OH)2D3-24-hydroxylase (24-OHase) mRNA 6 h after adding vitamin D compounds. The lower affinity of these two fluorinated analogs compared with that of 1 alpha,25(OH)2D3 for vitamin D binding protein in serum (serum DBP) seemed to be partly involved in their increased ability to activate the 24-OHase gene. A time course study revealed that the expression of the 24-OHase and osteopontin mRNAs in the cells incubated with 1 alpha, 25(OH)2D3 and F2-1 alpha,25(OH)2D3 attained maximal levels at 6 h for 24-OHase mRNA and 18 h for osteopontin mRNA, the both decreased thereafter. On the contrary, F6-1 alpha,25(OH)2D3 increased the expression of 24-OHase and osteopontin exponentially until 72 h. While F2-1 alpha,25(OH)2[1 beta-3H]D3 was catabolized quickly by ROB-C26 cells, F6-1 alpha,25(OH)2[1 beta-3H]D3 was slowly and quantitatively converted into putative 26,26,26,27,27,27-hexafluoro-23S-hydroxy[1 beta-3H]calcitriol (F6-1 alpha,23S,25(OH)3[1 beta-3H]D3). This may explain why the time-course profiles of the accumulation of mRNAs for 24-OHase and osteopontin differed in the cells exposed to the fluorinated analogs. In addition to the longer retention, unknown up-regulating mechanisms appeared to be involved in the exponential activation of the 24-OHase and osteopontin genes induced by F6-1 alpha,25(OH)2D3.

Animals↗

PubMed1995

Identification of phosphocholine-containing glycoglycerolipids purified from Mycoplasma fermentans-infected human helper T-cell culture as components of M. fermentans.

Previously, we have reported the occurrence of novel phosphocholine-containing glycoglycerolipids (GGPLs: GGPL-I and GGPL-III) in human helper T-cell (MT-4 cell line) (Mustuda et al, Glycoconjugate J. 10:340). However, the GGPLs disappeared from the MT-4 after treatment with an antimycoplasma agent. This disappearance suggested the involvement of microorganisms in the GGPL expression. In this paper, we show that the novel lipids are components of Mycoplasma fermentans itself. The supernatant fluid of the antimycoplasma agent-untreated Mt-4 cell culture produced mycoplasma-like colonies on PPLO agar plates, and PCR and immunological methods revealed the presence of M. fermentans. GGPLs were expressed again in the treated Mt-4 cells after infection with the isolated M. fermentans. The isolated M. fermentans had glycoglycerolipids corresponding to GGPL-I and GGPL-III. Thin-layer chromatography-mass spectrometry and immunological analyses showed that these glycoglycerolipid which were derived from the isolated M. fermentans were identical with GGPL-I and GGPL-III previously obtained. This is the first report that shows mycoplasma has phosphocholine-containing glycoglycerolipids.

Animals↗

PubMed1995

Protection of mice from Mycobacterium avium infection by recombinant interleukin-12.

Treatment with interleukin-12 (IL-12) significantly reduced the number of viable bacteria in mice infected with Mycobacterium avium. IL-12 itself, however, could not inhibit directly mycobacterial growth in vitro. IL-12 exerts antimycobacterial activity in vivo with a low level of toxicity, possibly by enhancing the host defense against the infection.

Animals↗

PubMed1995

Interleukin-10 expression and chemokine regulation during the evolution of murine type II collagen-induced arthritis.

In the enclosed study we have examined the expression and contribution of specific chemokines, macrophage inflammatory protein 1 alpha (MIP-1 alpha) and macrophage inflammatory protein 2 (MIP-2), and interleukin 10 (IL-10) during the evolution of type II collagen-induced arthritis (CIA). Detectable levels of chemotactic cytokine protein for MIP-1 alpha and MIP-2 were first observed between days 32 and 36, after initial type II collagen challenge, while increases in IL-10 were found between days 36 and 44. CIA mice passively immunized with antibodies directed against either MIP-1 alpha or MIP-2 demonstrated a delay in the onset of arthritis and a reduction of the severity of arthritis. On the contrary, CIA mice receiving neutralizing anti-IL-10 antibodies demonstrated an acceleration of the onset and an increase in the severity of arthritis. Interestingly, anti-IL-10 treatment increased the expression of MIP-1 alpha and MIP-2, as well as increased myeloperoxidase (MPO) activity and leukocyte infiltration in the inflamed joints. These data suggest that MIP-1 alpha and MIP-2 play a crucial role in the initiation and maintenance, while IL-10 appears to play a regulatory role during the development of experimental arthritis.

Animals↗

PubMed1995

The antagonistic effects of khellactones on platelet-activating factor, histamine, and leukotriene D4.

Khellactones of Peucedanum praeruptorum DUUN., including praeruptorins A (= Pd-Ia, 2) and B (= Pd-II,11), had an antagonistic effect specifically on platelet aggregation induced by platelet activating factor (PAF) among various aggregating agents examined, and represent a new class of PAF antagonists. We examined the effects of twenty compounds on PAF-induced platelet aggregation and on histamine- and leukotriene D4 (LTD4)-induced contractions in isolated guinea pig ileum. Compounds 2, (+/-)-cis-3',4'-diacetylkhellactone (3), (+/-)-cis-4'-acetyl-3'-crotonoylkhellactone (5), (+/-)-cis-4'-acetyl-3'-tetrolylkhellactone (6), (+/-)-cis-4'-acetyl-3'-tigloylkhellactone (7), (+/-)-cis-4'-acetyl-3'-(2"-methylbutyryl)khellactone (8), (+/-)-cis-3',4'-ditigloylkhellactone (10), and 11 all strongly inhibited PAF-induced platelet aggregation. (+/-)-cis-4'-Acetyl-3'-(2"-methyl-2"-dodecenoyl)khellactone (9), (+/-)-cis-4'-ethyl-3'-tigloylkhellactone (13), (+/-)-cis-4'-ethyl-3'-[N-(2"-triethylammonio)ethylcarbamoyl] khellactone iodide (16), (+/-)-trans-3',4'-diacetylkhellactone (18), (+/-)-trans-4'-acetyl-3'-crotonoylkhellactone (19), (+/-)-trans-4'-acetyl-3'-valerylkhellactone (20), (+/-)-trans-4'-acetyl-3'-isovalerylkhellactone (21), and (+/-)-trans-4'-acetyl-3'-tigloylkhellactone (22) were weakly inhibitory. Most of the compounds exhibited noncompetitive antagonist actions on histamine- and LTD4-induced contractions.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Interferon gamma modulates the expression of neutrophil-derived chemokines.

Specific cell recruitment to a site of acute inflammation is a crucial event characterized by the elicitation of mainly polymorphonuclear neutrophils (PMNs). Recently, it has been reported that PMNs can express and secrete chemotactic cytokines or chemokines, including IL-8, MIP-1 alpha, and MIP-1 beta. Moreover, PMN-derived chemokines are regulated by various soluble mediators, such as dexamethasone, prostaglandin E, classic chemoattractant factors (e.g., fMLP, C5a, leukotriene B4), IL-4, and IL-10. In this article we demonstrate that PMNs treated with IFN-gamma, a Th1-derived cytokine, can inhibit early mRNA expression for MIP-1 alpha, MIP-1 beta, and IL-8 (up to 8 hours post IFN-gamma addition), while augmenting their production at 24 hours post IFN-gamma addition. Furthermore, our studies demonstrate that one of the mechanisms for the activity of IFN-gamma in this system is via the autocrine activity of TNF-alpha. These data imply that PMN-derived chemokines are regulated by not only proinflammatory cytokines, including IL-1 beta and TNF-alpha, but also Th1- and Th2-derived cytokines, including IL-4, IL-10, and IFN-gamma. The role of these cytokine networks in regulating PMN-derived chemokines may play an important role in leukocyte elicitation during the initiation and maintenance of an inflammatory response.

Cells, Cultured↗

PubMed1994

Structure of a novel phosphocholine-containing glycoglycerolipid from Mycoplasma fermentans.

Mycoplasma fermentans is thought to be a pathogen of rheumatoid arthritis or cofactor of AIDS. A novel phosphocholine-containing glycoglycerophospholipid named GGPL-I was isolated from a M. fermentans-infected human helper T-cell culture. It was revealed that GGPL-I is a lipid component of the M. fermentans and a major immunological determinant. The GGPL-I was purified by DEAE-Sephadex column chromatography and repeated Iatrobeads column chromatography. The purified glycophospholipid was subjected to structural characterization by thin-layer chromatography, Fourier-transform infrared spectrometry, liquid secondary ion mass spectrometry, and nuclear magnetic resonance spectroscopy. Its structure was determined to be as follows: 6'-O-phosphocholine-alpha-glucopyranosyl-(1'-3)-1,2-diacyl-sn-glycerol. This glycoglycerophospholipid is unique in containing phosphocholine, which is attached to C-6 of glucose. The stereospecific numbering (sn) of naturally occurring GGPL-I was determined through comparison with chemically synthesized compounds.

Carbohydrate Conformation↗

PubMed1994

Simultaneous determination of deflazacort metabolites II and III, cortisol, cortisone, prednisolone and prednisone in human serum by reversed-phase high-performance liquid chromatography.

A new high-performance liquid chromatographic method for the analysis of human serum from subjects administered prednisolone or deflazacort has been established. Two deflazacort metabolites (metabolites II and III), prednisolone and its metabolite (prednisone), as well as cortisol and cortisone in human serum were analyzed simultaneously. These six compounds and the internal standard, betamethasone, were extracted from 1 ml of human serum using a Sep-Pak Plus Environmental C18 column and then separated on a Hypersil ODS (25 x 0.46 cm I.D.) column using a gradient system. The lower limit of quantitation for each compound was 10 ng/ml based on signal-to-noise ratio of 5 and calibration curve linearity. Within-day and between-day validations gave a coefficient of variation of less than 10% and a relative error of ca. 10% (n = 11).

Anti-Inflammatory Agents↗

PubMed1994

Regulation of neutrophil-derived chemokine expression by IL-10.

In this study, we examined IL-10 regulation of polymorphonuclear leukocyte (PMN)-derived chemokine expression. Studies demonstrated that IL-10 dose dependently suppressed the expression and production of PMN-derived macrophage inflammatory protein-1 alpha (MIP-1 alpha), MIP-1 beta, IL-8 mRNA, and protein. Although inhibition of protein synthesis was found to superinduce the expression of PMN-derived chemokine steady-state mRNA, the inhibitory activity of IL-10 was completely abrogated in the presence of either cycloheximide or puromycin. These data suggest that the effect of IL-10 on PMN-derived chemokine expression was through the production of de novo repressor protein(s). Next, we examined the half-life (t1/2) of chemokine mRNA by LPS-treated PMNs in the presence or absence of IL-10. The t1/2 of MIP-1 alpha, MIP-1 beta, and IL-8 mRNA from PMNs treated for 4 h with LPS before actinomycin-D (Ac-D) addition were approximately 40 min, 1.7 h, and 2 h, respectively, whereas the t1/2 from PMNs stimulated for 8 h before Ac-D were 2, 2, and > 9 h, respectively. Interestingly, IL-10 significantly accelerated the decay of all three of the above chemokine mRNA. The t1/2 of MIP-1 alpha, MIP-1 beta, and IL-8 mRNA from PMNs treated with LPS plus IL-10 compared with LPS alone was reduced by 62, 50, and 40%, respectively, at the 4-h time point and by 50, 25, and 70%, respectively, at the 8-h time point. These findings support the notion that PMNs are an important cellular source of both C-X-C and C-C chemokines, and that IL-10 regulates both inflammatory/immune responses by not only modulating the activities of T cell, B cell, and mononuclear phagocyte function, but also by inhibiting PMN-derived chemokine expression.

Base Sequence↗

PubMed1994

Glycolipid composition of human cataractous lenses. Characterization of Lewisx glycolipids.

We have studied the glycolipid composition of human cataractous lenses. Neutral and acidic lipid fractions were isolated by column chromatographies on DEAE-Sephadex and Iatrobeads. The neutral glycolipid fraction and acidic glycolipid fraction contained 0.6-0.9 micrograms of lipid-bound glucose (Glc) per mg of protein and 0.8-1.3 micrograms of lipid-bound sialic acid (NeuAc) per mg of protein, respectively. The neutral glycolipid fraction was found to contain LacCer (39.0% of total neutral glycolipids), Gb3 (16.2%), Gb4 (1.1%), nLc4 (5.0%), X (29.0%), and Y (9.2%). The acidic lipid fraction was found to contain mainly GM3 (33.1% of the total ganglioside fraction), GM1 (8.3%), LM1 (7.3%), GD1a (16.0%), and G (30.1%). The structures of neutral glycolipids X and Y and ganglioside G were elucidated by high performance thin-layer chromatography overlay method of glycolipids, gas-liquid chromatography, proton NMR spectrometry, and liquid secondary ion mass spectrometry as follows: 1) X, Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1'Cer, III3FucnLc4 (Lex); 2) Y, Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3Gal beta 1-4(Fuc alpha 1- 3)GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1'Cer, V3FucIII3FucnLc6; and 3) G, NeuAc alpha 2-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3 Gal-beta 1-4Glc beta 1-1'Cer, IV3NeuAcIII3FucnLc4 (sialosyl-Le(x)). A minor neutral glycolipid Z was isolated and tentatively characterized as GlcNAc beta 1-3?Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1'Cer (GlcNAc-Le(x)), suggesting that it may be the precursor of glycolipid Y. The major long-chain base of these human cataract glycolipids was C18:0 sphingosine (sphinganine). The major fatty acids were C16:0, C24:1 and C24:0, and monounsaturated fatty acids accounted for 40-55% of the total fatty acids.

Aged↗

PubMed1994

A simple and quantitative purification of glycosphingolipids and phospholipids by thin-layer chromatography blotting.

A new and simple method for purifying glycosphingolipids and phospholipids by using "TLC blotting" was established. Glycosphingolipids separated by two-dimensional thin-layer chromatography (TLC) were made visible with primuline reagent, and then bands were marked with a drawing colored pencil. The glycosphingolipids that separated on the HPTLC plate were transferred by TLC blotting to a polyvinylidene difluoride membrane together with the color marks. The marked areas were excised after which their glycosphingolipids were extracted and monitored by TLC. By this method, 20 glycosphingolipids showing homogeneous bands on a HPTLC plate were isolated from the neutral glycosphingolipid fraction of human meconium. Moreover, 10 kinds of acidic glycosphingolipids were purified as homogeneous bands from the bovine acidic glycosphingolipid fraction. The yields of glycosphingolipids (13 different ones) ranged from 68 to 92%, the mean value being 82.3%. The glycosphingolipids were confirmed to be purified as intact forms by mass spectrometric analysis and chromatographic mobilities on a HPTLC plate. The same procedure could also be used to purify phospholipids.

Animals↗

PubMed1994

[A case of rheumatoid arthritis associated with agranulocytosis during bucillamine treatment].

Bucillamine has been reported to have beneficial effects in rheumatoid arthritis. This report concerns a case of RA in which agranulocytosis developed while on a course of bucillamine. A 52-year-old female with RA developed a rapid fall in white blood cell count after 4 weeks of bucillamine treatment at daily dose of 50 mg. Agranulocytosis was diagnosed (WBC 1300/mm3, granulocytes 5%). The administration of bucillamine was halted and she was treated with only prophylactic antibiotic regime. The peripheral granulocyte count result rapidly reversed within 3 days after discontinuation of the bucilamine treatment. Anti-leukocyte antibody was detected by the leukocyte lysis phenomenon method during the period of agranulocytosis. And high intrinsic G-CSF activities were detected in the patient serum before the recovery period of agranulocytosis. Agranulocytosis is a rare side effect of bucillamine but it is potentially more harmful than other side effects. In treatment with bucillamine, therefore, the drug should be carefully administered and regular blood examinations carried out to prevent the occurrence of this side effect.

Agranulocytosis↗

PubMed1993

A bacterium lipopolysaccharide that elicits Guillain-Barré syndrome has a GM1 ganglioside-like structure.

There is a strong association between Guillain-Barré syndrome (GBS) and Penner's serotype 19 (PEN 19) of Campylobacter jejuni. Sera from patients with GBS after C. jejuni infection have autoantibodies to GM1 ganglioside in the acute phase of the illness. Our previous work has suggested that GBS results from an immune response to cross-reactive antigen between lipopolysaccharide (LPS) of the Gram-negative bacterium and membrane components of peripheral nerves. To clarify the pathogenesis of GBS, we have investigated whether GM1-oligosaccharide structure is present in the LPS of C. jejuni (PEN 19) that was isolated from a GBS patient. After extraction of the LPS, the LPS showing the binding activity of cholera toxin, that specifically recognizes the GM1-oligosaccharide was purified by a silica bead column chromatography. Gas-liquid chromatography-mass spectrometric analysis has shown that the purified LPS contained Gal, GalNAc, and NeuAc, which are sugar components of GM1 ganglioside. 1H NMR methods [Carr-Purcell-Meiboom-Gill (CPMG), total correlation spectroscopy (TOCSY), and nuclear Overhauser effect spectroscopy (NOESY)] have revealed that the oligosaccharide structure [Gal beta 1-3 GalNAc beta 1-4(NeuAc alpha 2-3)Gal beta] protrude from the LPS core. This terminal structure [Gal beta 1-3GalNAc beta 1-4(NeuAc alpha 2-3)Gal beta] is identical to the terminal tetrasaccharide of the GM1 ganglioside. This is the first study to demonstrate the existence of molecular mimicry between nerve tissue and the infectious agent that elicits GBS.

Adult↗

PubMed1993

Structure of novel gangliosides, deaminated neuraminic acid (KDN)-containing glycosphingolipids, isolated from rainbow trout ovarian fluid.

Two acidic glycosphingolipids were isolated and purified from rainbow trout ovarian fluid. They were designated as ovarian fluid gangliosides ofg-2a and ofg-2b. Both of these glycolipids were found to contain glucose, galactose, and N-acetylgalactosamine in a molar ratio of 1:2:1, but they differ by the presence of 2 mol of deaminated neuraminic acid (KDN; 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid) in ofg-2a and 1 mol each of KDN and 9-O-acetyl-KDN in ofg-2b. On the basis of composition analysis, methylation analysis, mild acid hydrolysis, fast atom bombardment mass spectrometry (FABMS), 400-MHz 1H nuclear magnetic resonance spectroscopy, and immunochemical analysis using a monoclonal antibody (mAb.kdn3G), the complete structures of these gangliosides were determined to be KDN alpha 2-->3Gal beta 1-->3GalNAc beta 1-->4(KDN alpha 2-->3)Gal beta 1-->4Glc beta 1-->Cer for ofg-2a [(KDN)GD1a] and 9-O-AcKDN alpha 2-->3Gal beta 1-->3GalNAc beta 1-->4(KDN alpha 2-->3)Gal beta 1-->4Glc beta 1-->Cer for ofg-2b [(KDN)GD1a(OAc+)]. The ceramide moieties (Cer) in both ofg-2a [(KDN)GD1a] and ofg-2b [(KDN)GD1a(OAc+)] were found by combining of the results from fatty acid analysis and FABMS measurements to be made up of 4-sphingenine and mainly a C24:1 fatty acyl chain (nervonate). The structures of ofg-2a and ofg-2b are novel, and they represent the second example of naturally occurring KDN-gangliosides. Mild acid hydrolysis of both ofg-2a and ofg-2b resulted in formation of (KDN)GM1a.

Animals↗