Urinary metabolite biomarkers of pregnancy complications associated with maternal exposure to particulate matter.

Particulate matter 2.5 (PM2.5) is associated with reproductive health and adverse pregnancy outcomes. However, studies evaluating biological markers of PM2.5 are lacking, and identifying biomarkers for estimating prenatal exposure to prevent pregnancy complications is essential. Therefore, we aimed to explore urine metabolites that are easy to measure as biomarkers of exposure. In this matched case-control study based on the PM2.5 exposure, 30 high PM2.5 group (>15 µg/m3) and 30 low PM2.5 group (<15 µg/m3) were selected from air pollution on pregnancy outcome (APPO) cohort study. We used a time-weighted average model to estimate individual PM exposure, which used indoor PM2.5 and outdoor PM2.5 concentrations by atmospheric measurement network based on residential addresses. Clinical characteristics and urine samples were collected from participants during the second trimester of pregnancy. Urine metabolites were quantitatively measured using gas chromatography-mass spectrometry following multistep chemical derivatization. Statistical analyses were conducted using SPSS version 21 and MetaboAnalyst 5.0. Small for gestational age and gestational diabetes (GDM) were significantly increased in the high PM2.5 group, respectively (P = 0.042, and 0.022). Fifteen metabolites showed significant differences between the two groups (P < 0.05). Subsequent pathway enrichment revealed that four pathways, including pentose and glucuronate interconversion with three pentose sugars (ribose, arabinose, and xylose; P < 0.05). The concentration of ribose increased preterm births (PTB) and GDM (P = 0.044 and 0.049, respectively), and the arabinose concentration showed a tendency to increase in PTB (P = 0.044). Therefore, we identified urinary pentose metabolites as biomarkers of PM2.5 and confirmed the possibility of their relationship with pregnancy complications.

Metabolomic profile of seminal plasma from Guzerá bulls (Bos indicus) with contrasting sperm freezability phenotypes.

The present study evaluated the seminal plasma metabolome of Bos indicus Guzerá bulls with good (n = 4) and poor (n = 5) sperm freezability. Animals were raised in natural pasture of a 'Caatinga' ecosystem, in the semi-arid region of Brazil. Seminal plasma samples were subjected to gas chromatography coupled to mass spectrometry and data, analysed using bioinformatics tools (Cytoscape with the MetScape plug-in). Sixty-two metabolites were identified in the bovine seminal plasma. Fatty acids and conjugates and organic compounds were the predominant seminal fluid metabolites, followed by carboxylic acids and derivatives, amino acids, benzenes and steroids and derivatives, carbohydrates and carbohydrate conjugates and prenol lipids. Multivariate analysis indicated a distinct separation of seminal plasma metabolomes from bulls with contrasting sperm freezability. Abundances of propanoic acid, d-ribose and glycine were greater in the seminal plasma of bulls with good sperm freezability. Heptadecanoic acid and undecanoic acid were the predominant in bulls of poor sperm freezability. Propanoic acid is an energy source for spermatozoa and may act as an antimicrobial component in semen. Glycine acts against oxidizing and denaturing reactions. d-ribose is also an energy source and reduces apoptosis and oxidative stress. Undecanoic acid may protect sperm against fungal damage. This study provides fundamental information approximately the seminal plasma metabolome of tropically adapted bulls and its association with sperm freezability. However, further studies with larger groups of animals are needed to validate those metabolites as markers of sperm freezability. This strategy could support the selection of sires with superior sperm cryoresistance.

Metabolite profiles and mass balance of fuzuloparib, a novel poly (ADP-ribose) polymerase inhibitor, in subjects with advanced solid cancers.

AIM: This trial (NCT04013048) investigated the metabolite profiles, mass balance and pharmacokinetics of fuzuloparib, a novel poly (ADP-ribose) polymerase inhibitor, in subjects with advanced solid cancers. METHODS: A single dose of 150 mg [14 C]fuzuloparib was administered to five subjects with advanced solid cancers. Blood, urine and faecal samples were collected, analysed for radioactivity and unchanged fuzuloparib, and profiled for metabolites. The safety of the medicine was assessed during the study. RESULTS: The maximum concentrations (Cmax ) of the total radioactivity (TRA) and unchanged fuzuloparib in plasma were 5.39 µg eq./mL and 4.19 µg/mL, respectively, at approximately 4 hours post dose. The exposure (AUC0-t ) of fuzuloparib accounted for 70.7% of the TRA in plasma, and no single metabolite was observed accounting for more than 10% of the plasma TRA. The recovery of TRA in excreta was 103.3 ± 3.8% in 288 hours, including 59.1 ± 9.9% in urine and 44.2 ± 10.8% in faeces. Sixteen metabolites of fuzuloparib were identified, including mono-oxidation (M1), hydrogenation (M2), di-oxidation (M3), trioxidation (M4), glucuronidation (M5, M7, M8) and de-ethylation (M6) products, and there was no specific binding between these metabolites and blood cells. Aliphatic hydroxylated fuzuloparib (M1-1) was the primary metabolite in the excreta, accounting for more than 40% of the dose for subjects. There were no serious adverse events observed in the study. CONCLUSION: Fuzuloparib was widely metabolized and excreted completely through urine and faeces in subjects with advanced solid cancer. Unchanged fuzuloparib was indicated to be the primary drug-related compound in circulation. [14 C]fuzuloparib was well-tolerated at the study dose.

96-Well Microtiter Plate Made of Paper: A Printed Chemosensor Array for Quantitative Detection of Saccharides.

Simple, rapid, and accurate detection methods for saccharides are potentially applicable to various fields such as clinical and food chemistry. However, the practical applications of on-site analytical methods are still limited. To this end, herein, we propose a 96-well microtiter plate made of paper as a paper-based chemosensor array device (PCSAD) for the simultaneous classification of 12 saccharides and the quantification of fructose and glucose among 12 saccharides. The mechanism of the saccharide detection relied on an indicator displacement assay (IDA) on the PCSAD using four types of catechol dyes, 3-nitrophenylboronic acid, and the saccharides. The design of the PCSAD and the experimental conditions for the IDA were optimized using a central composite design. The chemosensors exhibited clear color changes upon the addition of saccharides on the paper because of the competitive boronate esterification. The color changes were employed for the subsequent qualitative, semiquantitative, and quantitative analyses using an automated algorithm combined with pattern recognition for digital images. A qualitative linear discrimination analysis offered discrimination of 12 saccharides with a 100% classification rate. The semiquantitative analysis of fructose in the presence of glucose was carried out from the viewpoint of food analysis utilizing a support vector machine, resulting in clear discrimination of the various concentrations of fructose. Most importantly, the quantitative detection of fructose in two types of commercial soft drinks was also successfully carried out without sample pretreatments. Thus, the proposed PCSAD can be a powerful method for on-site food analyses that can meet the increasing demand from consumers for sensors of saccharides.

129Xe NMR-Protein Sensor Reveals Cellular Ribose Concentration.

Dysregulation of cellular ribose uptake can be indicative of metabolic abnormalities or tumorigenesis. However, analytical methods are currently limited for quantifying ribose concentration in complex biological samples. Here, we utilize the highly specific recognition of ribose by ribose-binding protein (RBP) to develop a single-protein ribose sensor detectable via a sensitive NMR technique known as hyperpolarized 129Xe chemical exchange saturation transfer (hyper-CEST). We demonstrate that RBP, with a tunable ribose-binding site and further engineered to bind xenon, enables the quantitation of ribose over a wide concentration range (nM to mM). Ribose binding induces the RBP "closed" conformation, which slows Xe exchange to a rate detectable by hyper-CEST. Such detection is remarkably specific for ribose, with the minimal background signal from endogenous sugars of similar size and structure, for example, glucose or ribose-6-phosphate. Ribose concentration was measured for mammalian cell lysate and serum, which led to estimates of low-mM ribose in a HeLa cell line. This highlights the potential for using genetically encoded periplasmic binding proteins such as RBP to measure metabolites in different biological fluids, tissues, and physiologic states.

Structure, antioxidant and immunomodulatory activity of a polysaccharide extracted from Sacha inchi seeds.

In this study, a novel water-soluble polysaccharide (PVLP-1) was extracted and purified from Sacha inchi (Plukenetia volubilis L.) seeds and the structure, antioxidant and immunomodulatory activity of PVLP-1 were investigated. PVLP-1 (144 kDa) consisted of glucose (69.76%), mannose (14.86%), arabinose (10.53%), galactose (2.42%), ribose (1.23%), rhamnose (0.27%) and xylose (0.93%). PVLP-1 displayed characteristic polysaccharide bands in Fourier transform NMR spectra and infrared. The primary structure of PVLP-1 was a heteropolysaccharide with a backbone of (1 â†’ 6)-linked glucose, sidechains of (1 â†’ 4)-linked mannose, (1 â†’ 4)-linked glucose and (1 â†’ 3, 6)-linked mannose and a residue unit of →1)-linked arabinose as revealed the methylation analysis. PVLP-1 possessed good water-holding capacity (WHC), oil-holding capacity (OHC) and antioxidant capacities. Besides, PVLP-1 induced the proliferation of RAW264.7 cell and enhanced the expression of inflammatory cytokines IL-6, TNF-alpha(TNF-α) and IL-1 beta (IL-1ß). The present study indicated that PVLP-1 possessed immune-enhancing bioactivities and could be functional food or adjuvant drug to improve biological immunity of immunodeficiency diseases and hypoimmunity.

Gallic acid as main product in the water extractives of Quercus frainetto ten.

The autoclave extraction of Hungarian oak (Quercus frainetto Ten.) wood gave 5.3% extractives. The chloroform soluble fraction obtained from the extracts of Q. frainetto allows to identify sesamin. The insoluble fraction contains mainly ribose and mannose. Water extraction in autoclave of thermo-treated Q. frainetto wood gave a lower amount of extractives (3.31%). The main product of the insoluble fraction was, on the basis of its mass spectrum, the monoacetyl derivative of gallic acid.

Streptomyces sediminis sp. nov. isolated from crater lake sediment.

A novel actinobacterial strain, MKSP12T, was isolated from coastal sediment of a crater lake in central Anatolia, Turkey. The taxonomic position of the strain was clarified using a polyphasic approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain MKSP12T is closely related to Streptomyces specialis GW 41-1564T with 97.1% sequence similarity. The strain produces aerial hyphae that differentiate into spiral chains of smooth surfaced spores and grows over a temperature range of 20-37 °C, at pH 7-11 and in the presence of 3% (w/v) sodium chloride. The cell wall amino acid is LL-diaminopimelic acid and the whole cell sugars are glucose and ribose. The polar lipids profile consists of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, an unidentified aminophospholipid, two unidentified phospholipids, an unidentified glycophospholipid and eight unidentified glycolipids; iso-C16:0, iso-C16:1 G, anteiso-C17:0 and anteiso-C17:1 ω9c were identified as the predominant cellular fatty acids (> 10%). Based on morphological and chemotaxonomic characteristics, and phylogenetic analyses, the strain is considered to represent a novel species in the genus Streptomyces, for which the name Streptomyces sediminis sp. nov. is proposed with the type strain MKSP12T (= DSM 100692T = KCTC 39613T).

Fluorescent Organic Nanoaggregates for Selective Recognition of d-(-)-Ribose in Biological Fluids and Oral Supplements.

Easily synthesizable, fluorescent, organic nanoaggregates have been utilized, for the first time, in the selective recognition of d-(-)-ribose at pH 5.5 in water. In the self-assembled form, the reactive sites of the monomer units can be properly organized to form an effective "recognition cleft" for ribose (limit of detection ≈23 µm), in which binding mainly occurs through a combination of hydrogen-bonding and CH⋅⋅⋅π interactions. The degree of agglomeration shows a profound influence on the extent of ribose sensing. A reduction in the optical response (≈1.8-fold) is observed when ribose is allowed to interact with nanoaggregates of smaller dimensions (a decrease in the hydrodynamic diameter from (≈212.7±10.2) to (≈44.6±3.5) nm). The protocol is also utilized for the estimation of ribose in human urine samples and oral supplements. Low-cost paper strips have also been developed for rapid, on-site detection of ribose without involving any sophisticated instruments or skilled personnel.

Overexpression and characterization of a recombinant l-ribose isomerase from Actinotalea fermentans ATCC 43279.

A putative l-ribose isomerase (EC 5.3.1.B3, l-RI) gene of Actinotalea fermentans ATCC 43279 was chemically synthesized, subcloned into pET-21b vector, and then overexpressed in Escherichia coli. After 0.5mM IPTG induction at 20°C for 20h, the recombinant l-RI was highly expressed with up to 50% of the total proteins. About 70% of the expressed l-RI appeared in the cell-free extract as a soluble form, and a high yield of active l-RI, 23,800U/L or 952U/g of wet cells, was achieved. The purified recombinant l-RI demonstrated its optimal activity at 45°C and pH 8 (in tricine-NaOH buffer). Metal ions are not required for l-RI activity, but Hg2+ inhibits its activity completely. The enzyme has a half-life of 74min at 50°C and an equilibrium ratio of 30:70 between l-ribulose and l-ribose at 45°C. The Vmax, kcat, KM, and catalytic efficiency (kcat/KM) of the recombinant l-RI against l-ribose are 232U/mg, 6700min-1, 31.3mM, and 214min-1mM-1, respectively. The high expression yield of the active recombinant A. fermentansl-RI and its highest Vmax, kcat, and catalytic efficiency among the characterized recombinant l-RIs suggest that this recombinant enzyme shows a potential application to produce l-ribose in industry.

Metal oxide-based dispersive solid-phase extraction coupled with mass spectrometry analysis for determination of ribose conjugates in human follicular fluid.

Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility. The pathogenesis of PCOS remains unclear and early diagnosis of PCOS is challenging. Follicular fluid provides a unique window in the critical processes during oocyte and follicular maturation, and the metabolic level of follicular fluid has important impact on the developmental potential of oocytes and subsequent embryos. Previous studies demonstrated some modified ribonucleosides in biological fluids were diseases related metabolites. In this respect, analysis of endogenous modified ribonucleosides in follicular fluids will facilitate the investigation of follicular development. Here, we developed a strategy for determination of ribose conjugates from follicular fluid using metal oxide-based dispersive solid-phase extraction (DSPE) coupled with liquid chromatography-multiple reaction monitoring-mass spectrometry analysis (DSPE-LC-MRM-MS/MS). Cerium dioxide (CeO2) was used to selectively recognize and capture cis-diol containing ribose conjugates from complex biological samples under basic environment. The trapped ribose conjugates were then easily released under acidic environment. The results showed that 50 potential ribose conjugates were detected in follicular fluid by the developed DSPE-LC-MRM-MS/MS method. We then further investigated the contents change of the detected ribose conjugates in follicular fluid from PCOS patients. The results indicated that the follicular fluid from healthy controls and PCOS patients can be clearly differentiated with the partial least squares-discriminate analysis (PLS-DA) based on the detected ribose conjugates. In addition, the contents of 8 ribose conjugates were significantly different between PCOS patients and healthy controls, which could potentially serve as the indicator of PCOS.

Enantioresolution and quantification of monosaccharides by comprehensive two-dimensional gas chromatography.

This work presents the development of a simple and efficient analytical protocol for the direct enantioselective resolution of sugars. A racemic mixture of the C3 sugar d,l-glyceraldehyde and the C5 monosaccharides d,l-arabinose, d,l-ribose, d,l-xylose, and d,l-lyxose was subjected to derivatization with trifluoroacetic anhydride, and corresponding derivatives were separated on a ß-cyclodextrin column with excellent resolution factors. Even though each aldopentose shows beside the linear form four predominant cyclic hemiacetals being the α- and ß-furanose along with the α- and ß-pyranose, we show that the overall enantiomeric excess of each compound can be precisely determined. Moreover, the measured detection limit for derivatized aldopentoses ranges from 0.015 to 0.019pmol on the column, while the quantification limit varies from 0.5 to 0.64pmol on the column.

Immunoassays of chemically modified polysaccharides, glycans in glycoproteins and ribose in nucleic acids.

Glycosylation of proteins plays an important role in health and diseases. At present new simple and inexpensive methods of glycoprotein analysis are sought. We developed a monoclonal antibody Manost 2.1 in mice after immunization with the adduct of mannan with Os(VI)temed complex (temed is N,N,N',N'-tetramethylethylenediamine). The specificity of this antibody to different biomolecules treated with Os(VI)temed was tested using dot blot immunoassay. Manost 2.1 showed specificity toward Os(VI)temed-modified polysaccharides, glycoproteins and ribonucleotide at the 3'-end in DNA. The antibody recognized neither the unmodified compounds nor the non-glycosylated proteins treated with Os(VI)temed. We also performed western blotting and Coomassie silver blue staining of mixtures of biomacromolecules treated with Os(VI)temed and identified specifically the modified glycoproteins. The immunochemical method using Manost 2.1 was compared with electrochemical analyses based on redox signals of the Os(VI)temed adducts, with similar results in terms of sensitivity. This new antibody-based approach opens the door for rapid and inexpensive analysis of glycans and glycoproteins in various scientific and medical fields, including cancer research and the future application of glycoprotein detection in clinical practice.

Faecal and Serum Metabolomics in Paediatric Inflammatory Bowel Disease.

BACKGROUND: Inflammatory bowel disease [IBD] is considered to result from the interplay between host and intestinal microbiota but its pathogenesis is incompletely understood. While IBD in adults has shown to be associated with marked changes in body fluid metabolomics, there are only few studies in children. Hence, this prospective study addressed the faecal and serum metabolomics in newly diagnosed paediatric IBD. METHODS: Paediatric patients with IBD undergoing diagnostic endoscopies and controls also with endoscopy but no signs of inflammation provided blood and stool samples in a tertiary care hospital. Blood inflammatory markers and faecal calprotectin levels were determined. The serum and faecal metabolomics were determined using ultra-high pressure liquid chromatography coupled to a mass spectrometer. RESULTS: Serum and faecal metabolite profiles in newly diagnosed paediatric IBD patients were different from healthy controls and categorized Crohn's disease and ulcerative colitis [UC] patients into separate groups. In serum, amino acid metabolism, folate biosynthesis and signalling pathways were perturbed in Crohn's disease; in UC also sphingolipid metabolic pathways were perturbed when compared to controls. In faecal samples, there was an increased level of several metabolites in UC in contrast to low or intermediate levels in Crohn's disease. There was a clear correlation with the level of inflammation, i.e. faecal calprotectin levels and the profile of various biologically important metabolites [carnosine, ribose and, most significantly, choline]. CONCLUSION: Characterization of inflammatory pattern using metabolomics analysis is a promising tool for better understanding disease pathogenesis of paediatric IBD.

International collaborative study for establishment of the 2nd WHO International Standard for Haemophilus influenzae type b polysaccharide.

In this report we present the results of a collaborative study for the preparation and calibration of a replacement International Standard (IS) for Haemophilus influenzae type b polysaccharide (polyribosyl ribitol phosphate; 5-d-ribitol-(1 â†’ 1)-ß-d-ribose-3-phosphate; PRP). Two candidate preparations were evaluated. Thirteen laboratories from 9 different countries participated in the collaborative study to assess the suitability and determine the PRP content of two candidate standards. On the basis of the results from this study, Candidate 2 (NIBSC code 12/306) has been established as the 2nd WHO IS for PRP by the Expert Committee of Biological Standards of the World Health Organisation with a content of 4.904 ± 0.185mg/ampoule, as determined by the ribose assays carried out by 11 of the participating laboratories.

Kribbella qitaiheensis sp. nov., a novel actinomycete isolated from soil.

A novel nocardioform actinomycete, designated strain NEAU-GQTH2-3(T), was isolated from muddy soil collected from a stream in Qitaihe, Heilongjiang Province, northeast China and characterized using a polyphasic approach. Phylogenetic analysis based on the 16S rRNA gene sequence demonstrated that the organism should be assigned to the genus Kribbella and forms a clade with Kribbella catacumbae JCM 14968(T) (99.2 % sequence similarity), Kribbella koreensis JCM 10977(T) (99.1 %), Kribbella ginsengisoli JCM 16928(T) (98.6 %) and Kribbella sancticallisti JCM 14969(T) (98.4 %), although with low bootstrap support. Morphological and chemotaxonomic properties of the isolate are in agreement with the description of the genus Kribbella. Chemotaxonomic characteristics include LL-diaminopimelic acid in the cell-wall peptidoglycan; glucose and ribose as the characteristic whole-cell hydrolysates; diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylinositol, a glycerolipid and an unidentified phospholipid as the predominant polar lipids; the major menaquinones MK-9(H4) and MK-9(H2); as well as iso-C15:0, iso-C16:0 and C17:1 ω7c being the predominant fatty acid components. Mycolic acids were not detected. Furthermore, the strain could be clearly distinguished by the combination of DNA-DNA hybridization results and some phenotypic characteristics from the closest phylogenetic relatives. Therefore, it is proposed that strain NEAU-GQTH2-3(T) represents a novel species of the genus Kribbella, for which the name Kribbella qitaiheensis sp. nov. is proposed. The type strain is NEAU-GQTH2-3(T) (=CGMCC 4.7215(T)  =JCM 30343(T)).

The effect of chilled conditioning at 4°C on selected water and lipid-soluble flavor precursors in Bison bison longissimus dorsi muscle and their impact on sensory characteristics.

Water and lipid-soluble flavor precursors were monitored using chromatography methods in the longissimus dorsi (LD) muscle of six grain-fed Bison bison, stored at 4°C for 2, 4, 8, 15 and 21 days in order to investigate their potential impact on sensory attributes of cooked bison meat. While pH and lipid-soluble compounds remained mostly unchanged, several changes in water-soluble compounds were observed. The breakdown of inosine-5'-monophosphate (IMP) led to increases in inosine, hypoxanthine and ribose (7-fold). Non-polar amino acids including valine, leucine and phenylalanine showed the most significant increases over 21 days. Trained panelists (n=8) found a significant increase at day 15 in vinegary/sour aroma, tenderness and juiciness, while chewiness and connective tissue significantly decreased. Although, most flavor attributes were undetectable, partial least squares (PLS) analysis revealed most water-soluble precursors were positively correlated with extended conditioning as well as beef and oily/fatty flavors. Quantitative changes observed in flavor precursors may be responsible for some sensory attributes developed during the heating process.

Analytical method development for directed enzyme evolution research: a high throughput high-performance liquid chromatography method for analysis of ribose and ribitol and a capillary electrophoresis method for the separation of ribose enantiomers.

Analytical methods were developed for a directed enzyme evolution research programme, which pursued high performance enzymes to produce high quality L-ribose using large scale biocatalytic reaction. A high throughput HPLC method with evaporative light-scattering detection was developed to test ribose and ribitol in the enzymatic reaction, a ß-cyclobond 2000 analytical column separated ribose and ribitol in 2.3 min, a C(18) guard column was used as an on-line filter to clean up the enzyme sample matrix and a short gradient was applied to wash the column, the enzymatic reaction solution can be directly injected after quenching. Total run time of each sample was approx. 4 min which provided capability of screening 4×96-well plates/day/instrument. Meanwhile, a capillary electrophoresis method was developed for the separation of ribose enantiomers, while 7-aminonaphthalene-1,3-disulfonic acid was used as derivatisation reagent and 25 mM tetraborate with 5 mM ß-cyclodextrin was used as electrolyte. 0.35%of D-ribose in L-ribose can be detected which can be translated into 99.3% ee of L-ribose. Derivatisation reagent and sample matrix did not interfere with the measurement.

Laceyella sediminis sp. nov., a thermophilic bacterium isolated from a hot spring.

A thermophilic bacterium, designated strain RHA1(T), was isolated from a sediment sample collected from a hot spring in Tengchong county, Yunnan province, south-west China, and was characterized by using a polyphasic approach. Based on its phenotypic and phylogenetic characteristics, strain RHA1(T) was affiliated to the genus Laceyella. The strain formed white aerial and yellow-white substrate mycelia, bearing single endospores on short sporophores. The cell-wall peptidoglycan contained meso-diaminopimelic acid. Whole-cell hydrolysates contained ribose and glucose. The major fatty acids were iso-C(15:0) (62.39%) and anteiso-C(15:0) (17.55%)(.) The predominant menaquinone was MK-9. The G+C content of the genomic DNA of strain RHA1(T) was 47.9 mol%. Based on DNA-DNA hybridization data, chemotaxonomic characteristics and differential physiological properties, strain RHA1(T) is considered to represent a novel species of the genus Laceyella, for which the name Laceyella sediminis sp. nov. is proposed; the type strain is RHA1(T) (=DSM 45263(T)=CCTCC AA 208058(T)).

A reinvestigation of the lipopolysaccharide structure of Helicobacter pylori strain Sydney (SS1).

In this study, we describe a reinvestigation of the lipopolysaccharide (LPS) structure of Helicobacter pylori strain Sydney (SS1) based on the NMR analysis of oligosaccharides obtained through the use of various degradations of the LPS as well as capillary electrophoresis-MS data. The results of the analysis indicated that the core region of a major H. pylori SS1 LPS glycoform consists of a backbone core oligosaccharide substituted at the D-glycero-D-manno-heptose (DD-Hep) residue by a linear chain composed of a trisaccharide fragment α-ddHep-3-α-L-Fuc-3-ß-GlcNAc, as previously demonstrated for H. pylori strain 26695, further elongated by consecutively added α-Glc and ß-Gal residues, and terminating in a novel linear chain consisting of 1,2-linked ß-ribofuranosyl residues, where the last ß-ribofuranosyl residue provides a point of attachment for the O-chain polysaccharide: [Formula: see text] where [2-ß-Ribf-](n) is a short (three to five residues) oligomer of 1,2-linked ß-ribofuranose (riban), and PS is a polysaccharide chain consisting of N-acetyllactosamine, substituted with α-Fuc to form Lewis (Le)-type structures. In addition to the previously identified LacNAc, Le(y) and Le(x) components, the O-chain polysaccharide of H. pylori SS1 LPS was found to contain a novel LacNAc unit carrying a phosphoethanolamine substituent at the O-6 position of ß-GlcNAc residues.