- Brasilane sesquiterpenoids and alkane derivatives from cultures of the basidiomycete Coltricia sideroides
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Three new brasilane-type sesquiterpenoids, brasilanes A-C (1-3), together with two new alkane derivatives, colisiderin A (4) and 7(E),9(E)-undecandiene-2,4,5-triol (5), were isolated from cultures of the basidiomycete Coltricia sideroides. Their structures were elucidated by NMR and MS data analyses. The absolute configuration of 4 was determined by TDDFT ECD calculations while brasilane-type sesquiterpenoids were isolated from cultures of mushroom for the first time. Compounds 2 and 4 showed weak cytotoxicities against HL-60 and SW480, respectively.
- Hu, Dong-Bao,Zhang, Shen,He, Jiang-Bo,Dong, Ze-Jun,Li, Zheng-Hui,Feng, Tao,Liu, Ji-Kai
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- Structural studies and biosynthetic aspects of the O-antigen polysaccharide from Escherichia coli O42
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The structure of the O-antigen polysaccharide (PS) from Escherichia coli O42 has been investigated by NMR spectroscopy as the main method, which was complemented with sugar analysis, mass spectrometry, and analysis of biosynthetic information. The O-specific chain of the O-deacylated lipopolysaccharide (LPS-OH) consists of branched tetrasaccharide-glycerol repeating units joined by phosphodiester linkages. The lipid-free polysaccharide contains 0.8 equiv of O-acetyl groups per repeating unit and has the following teichoic acid-like structure: Based on biosynthetic aspects, this should also be the biological repeating unit. This O-antigen structure is remarkably similar to that of E. coli O28ac, differing only in the presence or absence, respectively, of a glucose residue at the branching point. The structural similarity explains the serological cross-reactivity observed between strains of these two serogroups, and also their almost identical O-antigen gene cluster sequences. → 2)-(R)-Gro-(1-P-4)-β-D-GlcpNAc-(1→3)-β-D-Galf2Ac-(1→3)-α-D-GlcpNAc-(1→α-D-Glcp-(1→3).
- Fontana, Carolina,Weintraub, Andrej,Widmalm, G?ran
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- The structure of the O-antigen of Cronobacter sakazakii HPB 2855 isolate involved in a neonatal infection
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Strains of Cronobacter sakazakii (previously known as Enterobacter sakazakii) are medically recognized important Gram-negative bacterial pathogens that cause enterocolitis, septicemia, and meningitis, with a high mortality rate in neonates. The structure of their O-antigens, that form part of their somatic lipopolysaccharide (LPS) components, is of interest for their chemical and serological identification and their relationship to virulence. The O-polysaccharide (O-PS) of C. sakazakii HPB 2855 (SK 81), a strain isolated from an infant at the Hospital for Sick Children in Toronto in 1981, was shown to be a polymer of a partially O-acetylated-repeating hexasaccharide unit composed of d-glucose, d-galacturonic acid, 2-acetamido-2-deoxy-d-galactose, and l-rhamnose (1:1:1:3). From composition and methylation analysis, and the application of 1D and 2D 1H and 13C NMR spectroscopy, the O-PS was determined to be a polymer of a repeating oligosaccharide unit having the structure: [figure persented]
- MacLean, Leann L.,Vinogradov, Evgeny,Pagotto, Franco,Farber, Jeffrey M.,Perry, Malcolm B.
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- Structural studies of the O-antigen polysaccharide from Escherichia coli TD2158 having O18 serogroup specificity and aspects of its interaction with the tailspike endoglycosidase of the infecting bacteriophage HK620
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We have analyzed the O-antigen polysaccharide of the previously uncharacterized Escherichia coli strain TD2158 which is a host of bacteriophage HK620. This bacteriophage recognizes and cleaves the polysaccharide with its tailspike protein (TSP). The polysaccharide preparation as well as oligosaccharides obtained from HK620TSP endoglycosidase digests were analyzed with NMR spectroscopy. Additionally, sugar analysis was performed on the O-antigen polysaccharide and MALDI-TOF MS was used in oligosaccharide analysis. The present study revealed a heterogeneous polysaccharide with a hexasaccharide repeating unit of the following structure: A repeating unit with a d-GlcNAc substitution of d-Gal has been described earlier as characteristic for serogroup O18A1. Accordingly, we termed repeating units with d-Glc substitution at d-Gal as O18A2. NMR analyses of the polysaccharide confirmed that O18A1- and O18A2-type repeats were present in a 1:1 ratio. However, HK620TSP preferentially bound the d-GlcNAc-substituted O18A1-type repeating units in its high affinity binding pocket with a dissociation constant of 140 μM and disfavored the O18A2-type having a β-d-Glcp-(1→3)-linked group. As a result, in hexasaccharide preparations, O18A1 and O18A2 repeats were present in a 9:1 ratio stressing the clear preference of O18A1-type repeats to be cleaved by HK620TSP.
- Zaccheus, Mona V.,Broeker, Nina K.,Lundborg, Magnus,Uetrecht, Charlotte,Barbirz, Stefanie,Widmalm, Goeran
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- Triterpenoid saponins from Piptadeniastrum africanum (Hook. f.) Brenan
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One new triterpenoid saponin, named piptadeniaoside (1), along with two known saponins (2-3) have been isolated from the stem bark of Piptadeniastrum africanum. After previous isolation of flavone derivatives from this plant, new phytochemical investigati
- Noté, Olivier Placide,Tapondjou, Azefack Léon,Mitaine-Offer, Anne-Claire,Miyamoto, Tomofumi,Pegnyemb, Dieudonné Emmanuel,Lacaille-Dubois, Marie-Aleth
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- Polystachyasaponin with adjuvant activity from entada polystachya
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A new complex triterpenoid saponin, polystachyasaponin, was isolated from leaves of Entada polystachya (L.) DC. (Leguminosae) by using chromatographic methods. Its structure was established as 15,16-dihydroxy-3-[[O-β -D-xylopyranosyl-(1→2)-O-a-L-arabinopyranosyl-(1→6)-2- (acetylamino)-2-deoxy-β -D-glucopyranosyl]oxy]-(3β ,15α,16α)-olean-12-en-28-oic acid O-D-apio-β -D-furanosyl-(1→3)-O-β -D-xylopyranosyl-(1→2)-O-[β -D-glucopyranosyl-(1→4)]-6-O-[(2E,6R)- 6-hydroxy-2,6-dimethyl-1-oxo-2,7- octadienyl]-β -D-glucopyranosyl ester. Structural elucidation was performed using detailed analyses of 1H and 13C NMR spectra including 2D NMR spectroscopic techniques and chemical conversions. The hemolytic activity of the saponin was evaluated using in vitro assays, and its adjuvant potential on the cellular immune response against ovalbumin antigen was investigated using in vivo assays.
- Da Silva, Bernadete P.,Parente, Jose P.
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- Simplified determination of the content and average degree of acetylation of chitin in crude black soldier fly larvae samples
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Insects are considered a promising alternative protein source for food and feed, but contain significant amounts of chitin, often undesirable due to indigestibility, disagreeable texture and negative effect on nutrients intake. Fractionation strategies are thus increasingly being applied to isolate and valorize chitin separately. The analysis of chitin generally requires an intensive pretreatment to remove impurities, and derivatization to generate sufficient detector response. In this work, a liquid chromatography method, without pretreatment nor derivatization, was developed for the simultaneous determination of chitin content and degree of acetylation in non-purified samples of black soldier fly (BSF) larvae. The method is found to be more suitable, compared to traditional methods, for assessing high degrees of acetylation. For the first time, the degree of acetylation of BSF chitin (81 ± 2%) is reported. Additionally, the chitin content of BSF soft tissues is estimated at approximately 20% of the total chitin content (8.5 ± 0.1%).
- D'Hondt, Els,Soetemans, Lise,Bastiaens, Leen,Maesen, Miranda,Jespers, Vincent,Van den Bosch, Bert,Voorspoels, Stefan,Elst, Kathy
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supporting information
(2020/01/25)
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- Synthesis and AChE inhibitory activity of N-glycosyl benzofuran derivatives
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Six N-glycosyl benzofuran derivatives were synthesized by the catalysis of organic bases and condensation agents. The benzofuran derivatives were obtained by the reaction of various salicylaldehydes in acetone, and then hydrolyzed to the corresponding carboxylic acids. Finally, the target compounds were synthesized by acylation and the reaction conditions were optimized. The acetylcholinesterase (AChE) inhibitory activity of the desired compounds was tested using Ellman's method. Most of the compounds showed acetylcholinesterase-inhibition activity; N-(2,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-3-yl)benzofuran-2-carbxamide (5a) showed the best acetylcholinesterase inhibition, with an inhibitory rate of 84%.
- Cao, Zhi-Ling,Liu, Shu-Hao,Liu, Wei-Wei,Liu, Xiu-Jian,Ren, Shu-Ting,Shi, Da-Hua,Wang, Lei,Wang, You-Xian,Wu, Yu-Ran
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p. 162 - 166
(2020/01/28)
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- Enzymatic production of fully deacetylated chitooligosaccharides and their neuroprotective and anti-inflammatory properties
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Among several commercial enzymes screened for chitosanolytic activity, Neutrase 0.8L (a protease from Bacillus amyloliquefaciens) was selected in order to obtain a product enriched in deacetylated chitooligosaccharides (COS). The hydrolysis of different chitosans with this enzyme was followed by size exclusion chromatography (SEC-ELSD), mass spectrometry (ESI-Q-TOF), and high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). Neutrase 0.8L converted 10?g/L of various chitosans into mostly deacetylated oligosaccharides, yielding approximately 2.5?g/L of chitobiose, 4.5?g/L of chitotriose, and 3?g/L of chitotetraose. We found out that the neutral protease was not responsible for the chitosanolytic activity in the extract, while it could participate in the deacetylating process. The synthesized COS were tested in vitro for their neuroprotective (toward human SH-S5Y5 neurons) and anti-inflammatory (in RAW macrophages) activities, and compared with other functional ingredients, namely fructooligosaccharides.
- Santos-Moriano,Fernandez-Arrojo,Mengibar,Belmonte-Reche,Pe?alver,Acosta,Ballesteros,Morales,Kidibule,Fernandez-Lobato,Plou, Francisco J.
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- Scope and limitations of carbohydrate hydrolysis for de novo glycan sequencing using a hydrogen peroxide/metallopeptide-based glycosidase mimetic
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Acidic hydrolysis is commonly used as a first step to break down oligo- and polysaccharides into monosaccharide units for structural analysis. While easy to set up and amenable to mass spectrometry detection, acid hydrolysis is not without its drawbacks. For example, ring-destruction side reactions and degradation products, along with difficulties in optimizing conditions from analyte to analyte, greatly limits its broad utility. Herein we report studies on a hydrogen peroxide/CuGGH metallopeptide-based glycosidase mimetic design for a more efficient and controllable carbohydrate hydrolysis. A library of methyl glycosides consisting of ten common monosaccharide substrates, along with oligosaccharide substrates, was screened with the artificial glycosidase for hydrolytic activity in a high-throughput format with a robotic liquid handling system. The artificial glycosidase was found to be active towards most screened linkages, including alpha- and beta-anomers, thus serving as a potential alternative method for traditional acidic hydrolysis approaches of oligosaccharides.
- Peng, Tianyuan,Wooke, Zachary,Pohl, Nicola L.B.
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- Structure and gene cluster of the O-antigen of Escherichia coli O102
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The O-polysaccharide (O-antigen) of Escherichia coli O102 was studied by sugar analysis along with one- and two-dimensional 1H and 13C NMR spectroscopy. The following structure of the branched pentasaccharide repeating unit was estab
- Perepelov, Andrei V.,Senchenkova, Sof'Ya N.,Shashkov, Alexander S.,Knirel, Yuriy A.,Wang, Quan,Gong, Yanping,Wang, Lei
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p. 73 - 77,5
(2012/12/13)
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- Structure and gene cluster of the O-antigen of Escherichia coli O41
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The acidic O-polysaccharide (O-antigen) of Escherichia coli O41 was studied by sugar analysis along with 1D and 2D 1H and 13C NMR spectroscopy, and the following structure of the branched hexasaccharide repeating unit was established: This structure is unique among the known structures of bacterial polysaccharides. The O-antigen gene cluster of E. coli O41 was sequenced. The gene functions were tentatively assigned by a comparison with sequences in the available databases and found to be in full agreement with the E. coli O41 O-polysaccharide structure.
- Zhu, Hongfei,Perepelov, Andrei V.,Senchenkova, Sof'Ya N.,Shashkov, Alexander S.,Wang, Lei,Knirel, Yuriy A.
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experimental part
p. 86 - 89
(2012/03/22)
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- High-throughput determination of urinary hexosamines for diagnosis of mucopolysaccharidoses by capillary electrophoresis and high-performance liquid chromatography
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Mucopolysaccharidoses (MPS) diagnosis is often delayed and irreversible organ damage can occur, making possible therapies less effective. This highlights the importance of early and accurate diagnosis. A high-throughput procedure for the simultaneous determination of glucosamine and galactosamine produced from urinary galactosaminoglycans and glucosaminoglycans by capillary electrophoresis (CE) and HPLC has been performed and validated in subjects affected by various MPS including their mild and severe forms, Hurler and Hurler-Scheie, Hunter, Sanfilippo, Morquio, and Maroteaux-Lamy. Contrary to other analytical approaches, the present single analytical procedure, which is able to measure total abnormal amounts of urinary GAGs, high molecular mass, and related fragments, as well as specific hexosamines belonging to a group of GAGs, would be useful for possible application in their early diagnosis. After a rapid urine pretreatment, free hexosamines are generated by acidic hydrolysis, derivatized with 2-aminobenzoic acid and separated by CE/UV in ～10 min and reverse-phase (RP)-HPLC in fluorescence in ～21 min. The total content of hexosamines was found to be indicative of abnormal urinary excretion of GAGs in patients compared to the controls, and the galactosamine/glucosamine ratio was observed to be related to specific MPS syndromes in regard to both their mild and severe forms. As a consequence, important correlations between analytical response and clinical diagnosis and the severity of the disorders were observed. Furthermore, we can assume that the severity of the syndrome may be ascribed to the quantity of total GAGs, as high-molecular-mass polymers and fragments, accumulated in cells and directly excreted in the urine. Finally, due to the high-throughput nature of this approach and to the equipment commonly available in laboratories, this method is suitable for newborn screening in preventive public health programs for early detection of MPS disorders, diagnosis, and their treatment.
- Coppa, Giovanni V.,Galeotti, Fabio,Zampini, Lucia,MacCari, Francesca,Galeazzi, Tiziana,Padelia, Lucia,Santoro, Lucia,Gabrielli, Orazio,Volpi, Nicola
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scheme or table
p. 32 - 42
(2012/01/13)
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- Elucidation of the structure and characterization of the gene cluster of the O-antigen of Cronobacter sakazakii G2592, the reference strain of C. sakazakii O7 serotype
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The O-specific polysaccharide from the lipopolysaccharide of Cronobacter sakazakii G2592 was studied by sugar analysis along with 1D and 2D 1H and 13C NMR spectroscopy, and the following structure of the pentasaccharide repeating unit was established: β-D-GlcpNAc 1 ↓ 2 →3)-α-L-FucpNAc-(1→4)-α-D-GalpA-(1→3) -α-L-FucpNAc-(1→3)-β-D-GlcpNAc-(1→ This structure is unique among the known bacterial polysaccharide structures, which is in accord with classification of strain G2592 into a new C. sakazakii serotype, O7. It is in agreement with the O-antigen gene cluster of this strain, which was found between the housekeeping genes JUMPStart and gnd and characterized by sequencing and tentative assignment of the gene functions.
- Arbatsky, Nikolay P.,Wang, Min,Daeva, Elena D.,Shashkov, Alexander S.,Feng, Lu,Knirel, Yuriy A.,Wang, Lei
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experimental part
p. 1169 - 1172
(2011/06/19)
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- Heterogeneous structure of O-antigenic part of lipopolysaccharide of Salmonella telaviv (Serogroup O:28) containing 3-acetamido-3,6-dideoxy-D- glucopyranose
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The O-polysaccharide of Salmonella Telaviv was obtained by mild acid degradation of the lipopolysaccharide and studied by chemical methods (sugar and methylation analyses, Smith degradation, de-O-acetylation) and NMR spectroscopy. The structure of the O-polysaccharide was established. The repeating units that are proximal to the lipopolysaccharide core region mostly have a digalactose side chain and lack glucose, whereas those at the other end of the chain mostly do bear glucose but are devoid of the disaccharide side chain. This is the first structure established for the O-polysaccharide of a Salmonella serogroup O:28 (formerly M) strain characterized by subfactors O281 and O282. Knowledge of this structure and the structure of the O-polysaccharide of Salmonella Dakar (O281, O28 3) established earlier is crucial for determination of the exact structures associated with subfactors O281, O282, and O283 and elucidation of the genetic basis of the close relationship between Escherichia coli O71 and S. enterica O:28 O-antigens.
- Kumirska,Dziadziuszko,Czerwicka,Lubecka,Kunikowska,Siedlecka,Stepnowski
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experimental part
p. 780 - 790
(2012/01/19)
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- Structure of the O-antigen of Acinetobacter lwoffii EK30A; Identification of d-homoserine, a novel non-sugar component of bacterial polysaccharides
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We established a peculiar structure of the O-specific polysaccharide (O-antigen) of a psychrotrophic strain of Acinetobacter lwoffii, EK30A, isolated from a 1.6-1.8 million-year-old Siberian permafrost subsoil sediment sample. The polysaccharide was released by mild acid degradation of the lipopolysaccharide and studied using chemical analyses, Smith degradation, 1H and 13C NMR spectroscopy and mass spectrometry. It was found to contain d-homoserine, which is N-linked to 4-amino-4,6-dideoxy-d- glucose (Qui4N) and is N-acylated itself with acetyl in about half of the repeating units or (S)-3-hydroxybutanoyl group in the other half. The following is the structure of the tetrasaccharide repeating unit of the polysaccharide: →3)-β-d-Quip4NAcyl-(1→6)-α-d-Galp-(1→4) -α-d-GalpNAc-(1→3)-α-d-FucpNAc-(1→ where Acyl stands for either N-acetyl- or N-[(S)-3-hydroxybutanoyl]-d-homoseryl. The Royal Society of Chemistry 2010.
- Arbatsky, Nikolay P.,Kondakova, Anna N.,Shashkov, Alexander S.,Drutskaya, Marina S.,Belousov, Pavel V.,Nedospasov, Sergei A.,Petrova, Mayya A.,Knirel, Yuriy A.
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experimental part
p. 3571 - 3577
(2010/08/21)
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- Structure and gene cluster of the O-antigen of Salmonella enterica O60 containing 3-formamido-3,6-dideoxy-d-galactose
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An O-polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of Salmonella enterica O60 strain G1462, and the following unique structure of the O-unit was determined by chemical analyses along with 2D 1H and 13C NMR spectroscopy:{A figure is presented}. where Fuc3NFo stands for 3-formamido-3,6-dideoxygalactose. The structure established is in agreement with the O-antigen gene cluster of S. enterica O60, which contains putative genes for the synthesis of GDP-d-Man and dTDP-d-Fuc3NFo, three glycosyltransferase genes, and two O-unit-processing genes (wzx and wzy).
- Perepelov, Andrei V.,Liu, Bin,Senchenkova, Sof'ya N.,Shashkov, Alexander S.,Feng, Lu,Knirel, Yuriy A.,Wang, Lei
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experimental part
p. 1632 - 1634
(2010/08/22)
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- High yield production of monomer-free chitosan oligosaccharides by pepsin catalyzed hydrolysis of a high deacetylation degree chitosan
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The high molecular weight of chitosan, which results in a poor solubility at neutral pH values and high viscosity aqueous solutions, limits its potential uses in the fields of food, health and agriculture. However, most of these limitations are overcome by chitosan oligosaccharides obtained by enzymatic hydrolysis of the polymer. Several commercial enzymes with different original specificities were assayed for their ability to hydrolyze a 93% deacetylation degree chitosan and compared with a chitosanase. According to the patterns of viscosity decrease and reducing end formation, three enzymes-cellulase, pepsin and lipase A-were found to be particularly suitable for hydrolyzing chitosan at a level comparable to that achieved by chitosanase. Unlike the appreciable levels of both 2-amino-2-deoxy-d-glucose and 2-acetamido-2-deoxy-d-glucose monomers released from chitosan by the other enzymes after a 20 h-hydrolysis (4.6-9.1% of the total product weight), no monomer could be detected following pepsin cleavage. As a result, pepsin produced a higher yield of chitosan oligosaccharides than the other enzymes: 52% versus as much as 46%, respectively. Low molecular weight chitosans accounted for the remaining 48% of hydrolysis products. The calculated average polymerization degree of the products released by pepsin was around 16 units after 20 h of hydrolysis. This product pattern and yield are proposed to be related to the bond cleavage specificity of pepsin and the high deacetylation degree of chitosan used as substrate. The optimal reaction conditions for hydrolysis of chitosan by pepsin were 40 °C and pH 4.5, and an enzyme/substrate ratio of 1:100 (w/w) for reactions longer than 1 h.
- Roncal, Tomas,Oviedo, Alberto,de Armentia, Iratxe Lopez,Fernandez, Laura,Villaran, M. Carmen
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p. 2750 - 2756
(2008/04/06)
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- USE OF ORGANIC GLUCOSAMINE SALTS
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The present invention relates to the use of an organic glucosamine salt selected from glucosamine glucuronate, glucosamine ascorbate, glucosamine malate, glucosamine hydrogen malate, glucosamine citrate, glucosamine hydrogen citrate, and glucosamine dihydrogen citrate for the preparation of a medicament for the treatment of arthrosis and inflammation and pain associated with arthrosis. The present invention also relates to the use of an organic glucosamine salt, selected from the ones mentioned above, for the preparation of a nutritional supplement acting as a chondroprotector, to nourish the cartilage, protect the joints, prevent water deficit in the tissues that form the joint, improve the joints’ functional capacity, elasticity, and flexibility, and prevent and revert the physical overexertion syndrome in athletes, and the effects associated therewith.
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Page/Page column 7-8
(2008/06/13)
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- NEW GLYCOSPHINGOLIPIDS FROM MARINE ORGANISM
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The structure of several ceramides and cerebrosides, from three marine sponges and a soft coral collected in the Red Sea, are reported.Specifically, the structure detemination of ptiloceramide, halicerebroside A and amphicerebrosides B-F was achieved folloving suitable degradations and NMR measurements.
- Hirsch, S.,Kashman, Y.
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p. 3897 - 3906
(2007/10/02)
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- Platinum complexes of polyhydroxylated alkylamines and 2-polyhydroxylated alkyl-1,2-diaminoethanes
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Platinum complexes of polyhydroxylated alkylamines and 2-polyhydroxylated alkyl-1,2-diaminoethanes useful for inducing regression and/or palliation of cancer diseases in mammals.
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- Process for the preparation of cyclopropane carboxylic acid esters
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3-(Halogenovinyl- or propenyl-)-2,2-dimethyl cyclopropane-1-carboxylic acid esters, which are precursors of, or may themselves be, pyrethroid insecticides, are prepared by the reaction of certain halogenopentadienes with an alkyl diazoacetate in the presence of a catalyst which is a transition metal complex of certain chiral Schiff bases, which catalysts tend to increase the yield of preferred cis IR isomer relative to the other possible isomers.
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