No full-text available
To read the full-text of this research,
you can request a copy directly from the author.
STRUCTURAL INVESTIGATION OF RAW AND MODIFIED GLYCANS BY MALDI-TOF MASS SPECTROMETRY
... Chromatography and mass spectrometry (MS) are orthogonal methods of analysis because they are based on different physicochemical processes. The coupling of chromatography with mass spectrometry has offered the possibility of analyzing complex mixtures of analytes [5]. In addition to the classical use of standards, they use new variants of data processing and interpretation, which have been effectively translated to computational molecular simulation approaches [6][7][8]. ...
... where ∆ f H (I i + ) is the formation enthalpy of the resulted fragmentation ion, Σ∆ f H (F i ) is the sum of the formation enthalpies of accompanying fragments, and ∆ f H (M) is the molecular enthalpy of candidate structure. The meanings are similar for ∆ f G [11] For ease of reference, they were also assigned the following acronyms: DAG (diacetone-D-glucose) (1), DAM (diacetone-D-mannose) (2), DAGal (diacetone-D-galactose) (3), DAF (diacetone-D-fructose) (4), and DAS (diacetone-L-sorbose) (5). Through the perspective of the "Lock and Key" concept, the calculated profiles represent the keys. ...
... For ease of reference, they were also assigned the following acronyms: (4), and DAS (diacetone-L-sorbose) (5). Through the perspective of the "Lock and Key" concept, the calculated profiles represent the keys. ...
Accurate modeling of small molecules substantially reduces the logistical effort and time consumption to discover and then obtain chemicals with various applications. Molecular stereochemistry is fundamentally involved in the intermolecular interactions that give rise to biological activity. Establishing the configuration of the asymmetric carbon in diastereomers can be decisive in drug design. In the presented analytical technique, on the basis of quantitative structure–fragmentation relationship (QSFR), mass–energy profiles obtained by electron ionization mass spectrometry (EI-MS) for analytes are used, along with some profiles for candidate structures calculated by quantum chemical (QC) methods. Our paper establishes the analytical conditions that lead to the best matching scores of such profiles corresponding to the actual structures for some isomers of acetalized monosaccharides. The optimization was achieved by group validation of five analytes, using four independent variables: the QC method, the descriptor of calculated energy, the impact energy of electrons, and the descriptor of experimental energy. The true structures were obtained using experimental profiles obtained at low electronic impact energies, and profiles were calculated using the DFT (B3LYP/6-31G) and RM1 QC methods. The double quantification of the ionic mass and the energy that generates it, for only a few primary ions of the mass spectrum, even allows the differentiation of acetalized diastereomers.
... Moreover, another caveat is the relatively small sample size (45 patients per each group). This can decrease the statistical power while also limiting the robustness of subgroup analyses [23,29,66,67]. While a small sample size limits generalizability, it offers certain advantages, such as costeffectiveness, faster patient turnaround, and focused data collection and analysis [29,68]. ...
Background: Although TRAIL is a potent propapoptotic factor, its role in cardiovascular disease (CVD) remains unclear. This pilot exploratory study investigated serum TRAIL changes along the CVD continuum. We focused on two successive phases of this spectrum (systemic arterial hypertension and heart failure), with emphasis on acute cardiac events due to their immediate clinical significance. Methods: The study population included 90 age- and sex-matched patients hospitalized with hypertensive urgencies (HTUs) or acute decompensation episodes (ADHF). Key echocardiographic, endothelial, cardiometabolic, renal, and liver markers were assessed alongside TRAIL levels. Results: ADHF patients showed significantly elevated TRAIL concentrations, suggesting a progressive rise in TRAIL levels along the CVD continuum. They exhibited worse cardiac, hematologic, and renal profiles, with longer hospital stays and the cachexic phenotype. TRAIL correlated directly with asymmetric dimethylarginine, C-reactive protein, and admission potassium in ADHF patients. In hypertensive subjects, it correlated directly with asymmetric dimethylarginine and inversely with erythrocyte size variability. TRAIL may, thus, serve as a compensatory mechanism in HF, with potential as a biomarker for acute cardiovascular events. Conclusions: TRAIL dynamics provide valuable insights into CVD pathophysiology, particularly in acute settings, warranting further investigation to clarify its role in the broader context of apoptosis and cardiovascular health.
Cosmetic products are chemical substances or mixtures used on the skin, hair, nails, teeth, and the mucous membranes of the oral cavity, whose use is intended to clean, protect, correct body odor, perfume, keep in good condition, or change appearance. The analysis of cosmetic ingredients is often challenging because of their huge complexity and their adulteration. Among various analytical tools, mass spectrometry (MS) has been largely used for compound detection, ingredient screening, quality control, detection of product authenticity, and health risk evaluation. This work is focused on the MS applications in detecting and quantification of some common cosmetic ingredients, i.e., preservatives, dyes, heavy metals, allergens, and bioconjugates in various matrices (leave-on or rinse-off cosmetic products). As a global view, MS-based analysis of bioconjugates is a narrow field, and LC- and GC/GC×GC-MS are widely used for the investigation of preservatives, dyes, and fragrances, while inductively coupled plasma (ICP)-MS is ideal for comprehensive analysis of heavy metals. Ambient ionization approaches and advanced separation methods (i.e., convergence chromatography (UPC²)) coupled to MS have been proven to be an excellent choice for the analysis of scented allergens. At the same time, the current paper explores the challenges of MS-based analysis for cosmetic safety studies.
This review is the tenth update of the original article published in 1999 on the application of matrix‐assisted laser desorption/ionization (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2020. Also included are papers that describe methods appropriate to analysis by MALDI, such as sample preparation techniques, even though the ionization method is not MALDI. The review is basically divided into three sections: (1) general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation, quantification and the use of arrays. (2) Applications to various structural types such as oligo‐ and polysaccharides, glycoproteins, glycolipids, glycosides and biopharmaceuticals, and (3) other areas such as medicine, industrial processes and glycan synthesis where MALDI is extensively used. Much of the material relating to applications is presented in tabular form. The reported work shows increasing use of incorporation of new techniques such as ion mobility and the enormous impact that MALDI imaging is having. MALDI, although invented nearly 40 years ago is still an ideal technique for carbohydrate analysis and advancements in the technique and range of applications show little sign of diminishing. This article is protected by copyright. All rights reserved.
The bile duct system has two distinct components: one intrahepatic and another extrahepatic. Both components are subject to large anatomical variability. Knowledge of intraparenchimatous bile duct system distribution is particularly useful for planning and performing major surgical resection and liver transplantation. For this reason, the training of students and medical residents must use liver corrosion casts. On the 130 pieces of hepatic corrosion casts, a percentage of 80.75% of cases have modal typology, homologated by Terminologia Anatomica (1998). On a percentage of 19.25% of the studied cases were found major variations of the intrahepatic bile duct system (classified into four morphological types). In 16.15% of cases, the posterior branch in his passage to the left hepatic duct intersects the main portal fissure. Medial and lateral branches showed no major variations on the studied material. Use of human intrahepatic bile duct system corrosion casts with major anatomical variations, can compensate for lack of clinical material in training of medical students and residents.
The five anti-complementary polysaccharides (MFKF-NP, MFKF-AP1, , and MFKF-AP2, ) were separated from hot water extracts of fruiting bodies of Fomes fomentarius by two subsequent column chromatography using DEAE-sepharose FF and Concanavalin A-sepharose 4B. The order of anti-complementary activity was MFKF-AP1 > MFKF-AP1 > MFKF-AP2 > MFKF-AP2 > MFKF-NP > Polysaccharide Krestine (PSK). Especially, MFKF-AP1 among those showed the most excellent anti-complementary activity (70% of ITCH50 value at ). The monosaccharide composition analysis by gas chromatography indicates that MFKF-AP1 and are a kind of homoxylan consisted mainly of xylose above 97%. Molecular weight of MFKF-AP1, major anti-complementary polysaccharide, was estimated to be about 12,000 by high performance liquid chromatography (HPLC). After the incubation of the serum with MFKF-AP1 in the presence or absence of and ions, its anti-complementary activity was investigated. This result indicated that MFKF-AP1 seems to be activator both on the classical and the alternative pathway of complement activation.
Metabolic therapy constitutes a relatively new therapeutic option for ischemic heart disease (IHD). Metabolic agents including Trimetazidine [1-(2,3,4-Trimethoxybenzyl) piperazine] (TMZ) are currently used as antiischemic cardiac drugs to alleviate this internal metabolic disturbance. The present study focused on the assessment of the beneficial effects of TMZ as additional medication to the conventional medical therapy in patients with myocardial infarction. The obtained results showed an increase of superoxide dismutase (SOD) activities and a faster normalization of total sialic acid (TSA) levels in patients with TMZ add-on therapy, in comparison to the control group, indicating a stabilization of the ischemic process under TMZ therapy, with decreased free radical production and restoration of the antioxidant capacity and of the membrane lesions. The present findings emphasize the importance of TMZ administration to prevent reperfusion-mediated cardiac injury and dysfunction and demonstrate that this promising therapeutic approach is worthy of further research.
Natural polysaccharides are renewable with a high degree of biocompatibility, biodegradability, and ability to mimic the natural extracellular matrix (ECM) microenvironment. Comprehensive investigations of polysaccharides are essential for our fundamental understanding of exploiting its potential as bio-composite, nano-conjugate and in pharmaceutical sectors. Polysaccharides are considered to be superior to other polymers, for its ease in tailoring, bio-compatibility, bio-activity, homogeneity and bio-adhesive properties. The main focus of this review is to spotlight the new advancements and challenges concerned with surface modification, binding domains, biological interaction with the conjugate including stability, polydispersity, and biodegradability. In this review, we have limited our survey to three essential polysaccharides including cellulose, starch, and glycogen that are sourced from plants, microbes, and animals respectively are reviewed. We also present the polysaccharides which have been extensively modified with the various types of conjugates for combating last-ditch pharmaceutical challenges.
The liver segmentation is determined by the distribution of the vascular and ductal hepatic elements; from this, the hepatic portal vein (HPV), the central element of liver afferent pedicle, is the most important. The posterior branch (PB) is serving right lateral division (RLD) of the liver and presents the lowest morphological variability. On a total of 125 pieces of liver corrosion casts, one examined the intraparenchymal distribution of portal PB and the segmentation of RLD. Regarding the intraparenchymal distribution of the branches in the RLD of the liver, we showed four distinct morphological types: Type I (77.6% of cases) in which the PB bifurcate symmetrically in branch of segments VI and branch of segment VII; Type II (8.8% of cases) in which the PB bifurcate in branch of segment VII and an inferior branch, that bifurcate branch of segment VI and branch of segment VIA; Type III 12.8% of cases) in which the PB bifurcate in branch of segment VI and a superior branch, that bifurcate in branch of segment VII and branch of segment VIIA; Type IV (0.8% of cases) in which the PB trifurcate in branch of segment VI, branch of posterior intermediate segments, and branch of segment VII. Knowledge of these morphological types of portal PB is important for clinical and surgical practice.
An original strategy was set-up in order to develop new azo compounds which incorporate in their structure 4,4'-diaminodiphenylmethane (DADFM) and low molecular weight maltodextrine. The synthesis of the model compounds involved the functionalisation of DADFM with the maltodextrine, the conversion of amino functionalized maltodextrine in a diazonium salt and the coupling of reaction with H and R acids. The compounds were characterized by UV-VIS, IR, mass spectroscopy and thermal analysis. This new design unreported in literature will confer to the synthesized compounds a greater solubility, on the entire pH range, which will result in an extended application field of these dyes, on various substrate types.
The structure of two very similar glucuronoglucans, isolated from the fruit bodies of Polyporus fomentarius and Polyporus igniarius, have been investigated. They both contain a backbone of a branched β-d-glucan, in which the d-glucose residues are connected by (1→3)- and (1→6)-linkages. Chains, containing an average of 4–5 β-(1→4)-linked d-glucuronic acid residues, are β-linked to the 3-position of some d-glucose residues in the backbone.G.l.c.-mass spectrometry was used for the qualitative and quantitative analysis of the methylated sugars obtained on hydrolyses of the methylated and the methylated-reduced polysaccharide. The reduction was performed with lithium aluminium deuteride, and the methyl ethers derived from d-glucuronic acid residues were distinguished from those derived from d-glucose residues by their mass spectra.
The Influence of the wavelength on laser desorptlon of Ions from organlc wilds is exemplified for various amino aclds and dlpeptldes: some absorblng and some nonabsorbing at 266 nm and all nonabsorbing at 355 nm. The presence of cias- slcai absorptlon lowers the threshold irradiance for the de- tectlon of sample-specific Ions and increases the ratlo of molecular-to-fragment Ions. These observations promlse to be of considerable value for future practlcal appllcatlon of laser desorptlon mass spectrometry of organics. The en- hanced ion yield of nonabsorblng molecules In an absorblng matrlx Is presented as an example. Two models for the wavelength influence are discussed, one assumlng a pre- domlnantly resonant one-photon energy transfer for hlghly absorblng samples and the other postulating an Increased Ion yield vla excited states.
A summary of the ion types observed in the Fast Atom Bombardment Mass Spectrometry (FAB-MS) and collision induced decomposition (CID) MS/MS spectra of glycoconjugates (glycosphingolipids, glycopeptides, glycosides and carbohydrates) is presented. The variety of product ion types that arise by cleavages within the carbohydrate moieties has prompted us to introduce a systematic nomenclature to designate these ions. The proposed nomenclature has been developed primarily for FAB-MS, but can be used as well for other ionization techniques [field desorption (FD), direct chemical ionization (DCI), laser desorption/Fourier transform (LD/FT), etc.], and is applicable to spectra recorded in either the positive or negative ion mode during both MS and MS/MS experiments.Ai, Bi and Ci labels are used to designate fragments containing a terminal (nonreducing end) sugar unit, whereas Xj, Yj and Zj represent ions still containing the aglycone (or the reducing sugar unit). Subscripts indicate the position relative to the termini analogous to the system used in peptides, and superscripts indicate cleavages within carbohydrate rings.FAB-MS/MS spectra of a native glycosphingolipid and glycopeptide, and a permethylated ganglioside are shown as illustrations.
The use of a matrix for pulsed ultraviolet laser desorption mass spectrometry is shown to extend its applicability into the range of larger, thermally labile biomolecules. The matrix compounds tested show strong resonance absorption at the laser wavelength of 266 nm and can be either solid or liquid. Characteristic features of the matrix-assisted LD mass spectra are high quasimolecular ion yield with little or no fragmentation and only a few signals in the low mass range. The matrix effect is discussed in the light of three possible mechanisms: an effective and controllable energy transfer of the laser energy to the condensed phase by predominantly one-photon absorption, the creation of a uniform and soft disintegration of the condensed phase at moderate irradiances independent of the analyte's individual properties, and an enhancement of ionization yield by protonation via excited state molecules.
In the following, the first results on ultraviolet laser desorption (UVLD) of bioorganic compounds in the mass range above 10000 daltons are reported. Strong molecular ion signals were registered by use of an organic matrix with strong absorption at the wavelength used for controlled energy deposition and soft desorption (7)
This review describes the application of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry to carbohydrate analysis and covers the period 1991-1998. The technique is particularly valuable for carbohydrates because it enables underivatised, as well as derivatised compounds to be examined. The various MALDI matrices that have been used for carbohydrate analysis are described, and the use of derivatization for improving mass spectral detection limits is also discussed. Methods for sample preparation and for extracting carbohydrates from biological media prior to mass spectrometric analysis are compared with emphasis on highly sensitive mass spectrometric methods. Quantitative aspects of MALDI are covered with respect to the relationship between signal strength and both mass and compound structure. The value of mass measurements by MALDI to provide a carbohydrate composition is stressed, together with the ability of the technique to provide fragmentation spectra. The use of in-source and post-source decay and collision-induced fragmentation in this context is described with emphasis on ions that provide information on the linkage and branching patterns of carbohydrates. The use of MALDI mass spectrometry, linked with exoglycosidase sequencing, is described for N-linked glycans derived from glycoproteins, and methods for the analysis of O-linked glycans are also covered. The review ends with a description of various applications of the technique to carbohydrates found as constituents of glycoproteins, bacterial glycolipids, sphingolipids, and glycolipid anchors.
A combined methodology for obtaining at the preparative scale and characterization by nanoelectrospray ionization (nanoESI) quadrupole time-of-flight (QTOF) mass spectrometry (MS) and tandem MS (MS/MS) of linear polysaccharides modified at the reducing end is presented. Two polydisperse maltodextrins (1000 and 3000 Da) and a high molecular weight polydisperse dextran (6000 Da) were coupled with hexamethylenediamine (HMD). The coupling products were analyzed by nanoESI-QTOF-MS in the positive ion mode and MS/MS using collision-induced dissociation (CID) at low energies. In the HMD-M1000 mixture, the polysaccharide chains containing from 2 to 8 Glc residues were detected, while in HMD-M3000 we identified a complete series of chains containing from 8 to 21 Glc moieties. The employed ESI conditions enhanced the detection of chains with up to 46 Glc residues in the HMD-D6000 sample. By optimized MS/MS, HMD-modified polysaccharides of 3, 4, 5, 12 and 46 degrees of polymerization yielded product ion spectra exhibiting the whole set of Y- and B-fragment ions. The MS structural data were obtained within a few minutes of signal acquisition, with a sample consumption situating the analysis sensitivity in the picomolar range.
Botanical polysaccharides exhibit a number of beneficial therapeutic properties, and it is thought that the mechanisms involved in these effects are due to the modulation of innate immunity and, more specifically, macrophage function. In this review, we summarize our current state of understanding of the macrophage modulatory effects of botanical polysaccharides isolated from a wide array of different species of flora, including higher plants, mushrooms, lichens and algae. Overall, the primary effect of botanical polysaccharides is to enhance and/or activate macrophage immune responses, leading to immunomodulation, anti-tumor activity, wound-healing and other therapeutic effects. Furthermore, botanical and microbial polysaccharides bind to common surface receptors and induce similar immunomodulatory responses in macrophages, suggesting that evolutionarily conserved polysaccharide structural features are shared between these organisms. Thus, the evaluation of botanical polysaccharides provides a unique opportunity for the discovery of novel therapeutic agents and adjuvants that exhibit beneficial immunomodulatory properties.
A novel strategy was developed to extend the application of electrospray ionization (ESI) Fourier transform ion cyclotron resonance (FTICR) mass spectrometry (MS) to the analysis of long-chain polysaccharides. High molecular weight polydisperse maltodextrins (poly-α(1-4) glucose) and dextrans (poly-α(1-6) glucose) were chosen as model compounds in the present study. Increased ionization efficiency of these mixtures in the positive ion mode was achieved upon modification of their reducing end with nitrogen-containing groups. The derivatization method is based on the formation of a new C-N bond between 1,6-hexamethylenediamine (HMD) and the reducing end of the polysaccharide, which exists in solution as an equilibrium between the hemiacetal and the open-ring aldehyde form. To achieve the chemical modification of the reducing end, two synthetic pathways were developed: (i) coupling of HMD by reductive amination and (ii) oxidation of the hemiacetal to lactone, followed by ring opening by HMD to yield the maltodextrin lactonamide of 1,6-hexanediamine (HMMD). Amino-functionalized polysaccharides were analyzed by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FTICR-MS) in the positive ion mode by direct flow injection. The hexamethylenediamine (HMD) and maltodextrin lactonamide of 1,6-hexanediamine (HMMD) moieties provide increased proton affinities which dramatically improve the detection of the long-chain polysaccharides by FTICR-MS. The present approach allowed for identification of single components in mixtures with prominent heterogeneity in the degree of polymerization (DP), without the need for chromatographic separation prior to MS. The high mass accuracy was essential for the unambiguous characterization of the species observed in the analyzed mixtures. Furthermore, molecular components containing up to 42 glucose residues were detected, representing the largest polysaccharide chains analyzed so far by ESI FTICR-MS.
Reductive aminations of carbonyl compounds with borohydride and borane reducing agents
- E W Baxter
- A B Reitz
Baxter EW, Reitz AB, Reductive aminations of
carbonyl compounds with borohydride and borane
reducing agents. Org React., 2001; 59: 1-714.
Investigation of neutral polysaccharides from Fomes fomentarius. A preliminary study
- L Bojin
- C Cojocaru
- M Georgescu
- M Puiu
- M C Pascariu
- A Serb
- D Puscasiu
- C Tatu
- E Sisu
Bojin L, Cojocaru C, Georgescu M, Puiu M,
Pascariu MC, Serb A, Puscasiu D, Tatu C, Sisu E,
Investigation of neutral polysaccharides from Fomes
fomentarius. A preliminary study. Fiziologia -Physiology, 2018; 28.2(96): 20-27.
Polysaccharides of wood-destroying fungus Fomes fomentarius extracted with water
- A Kardošová
- K Babor
- J Rosík
- J Kubala
Kardošová A, Babor K, Rosík J, Kubala J,
Polysaccharides of wood-destroying fungus Fomes
fomentarius extracted with water. Chemické Zvest.,
1969; 23(6): 454-461.
Synthesis and structural characterization of maltodextrins functionalized with hexamethylenediamine
- I Sisu
- V Udrescu
- C Flangea
- S Tudor
- N Dinca
- L Rusnac
- A Zamfir
- E Sisu
Sisu I, Udrescu V, Flangea C, Tudor S, Dinca N,
Rusnac L, Zamfir A, Sisu E, Synthesis and structural
characterization of maltodextrins functionalized with
hexamethylenediamine. Cent Eur J Chem., 2009;
7(1): 66-73.