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101.
Le Roy RJ 《Journal of Molecular Spectroscopy》1999,194(2):189-196
A new way of representing vibration-rotation term values for multiple isotopomers of a given electronic state of a diatomic molecule is presented which resolves problems associated with the way the conventional combined isotopomer expansion represents the atomic mass-dependent JWKB and Born-Oppenheimer breakdown correction terms. Its application to infrared and microwave data for HF and DF yields new Dunham expansion coefficients and Born-Oppenheimer breakdown correction terms for this species. This procedure is implemented in a generally available computer program for fitting to various types of data involving one or several electronic states of multiple isotopomers of a diatomic molecule. Copyright 1999 Academic Press. 相似文献
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Chaidedgumjorn A Suzuki A Toyoda H Toida T Imanari T Linhardt RJ 《Journal of chromatography. A》2002,959(1-2):95-102
Chemically per-O-sulfonated polysaccharides, including glycosaminoglycans (GAGs) and hyaluronan oligosaccharides were analyzed using high-performance size-exclusion chromatography (HPSEC) with suppressed conductivity detection. The results were compared to those obtained by gel filtration HPLC using UV detection or fluorescence detection after the post-column reaction with 2-cyanoacetamide in strong alkaline solution. Analysis was performed on a TSKgel G3000SWXL HPSEC column in 5 mM boric acid (pH 7.0 adjusted by 10 mM NaOH). The use of conductivity detection, in the absence of any derivatization and under isocratic conditions gave a limit of detection in the picogram range. Preliminary studies suggest that this approach may be particularly useful in examining sulfonated polysaccharides and oligosaccharides having no UV chromophore, such as those prepared from O-sulfonated fucans and galactans isolated from algae. 相似文献
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Ultraviolet matrix-assisted laser desorption/ionization mass spectrometric (UV-MALDI-MS) analysis of highly acidic, thermally labile species such as glycosaminoglycan-derived oligosaccharides is complicated by their poor ionization efficiency and tendency to fragment through the loss of sulfo groups. We have utilized a systematic approach to evaluate the effect of alkali metal counterions on the degree of fragmentation through SO3 loss from a highly sulfated model compound, sucrose octasulfate (SOS). The lithium, sodium, potassium, rubidium, and cesium salts of SOS were analyzed by UV-MALDI-time-of-flight (TOF)MS using an ionic liquid matrix, bis-1,1,3,3-tetramethylguanidinium alpha-cyano-4-hydroxycinnamate. The positive-ion and negative-ion MALDI mass spectra of five alkali metal salts of SOS were compared in terms of the degree of analyte fragmentation through the SO3 loss and the absolute intensity of a molecular ion signal. Experimental results demonstrate that the lithium, sodium, and potassium salts of SOS undergo some degree of fragmentation through the loss of SO3, whereas the fragmentation through the loss of SO3 in the rubidium and cesium salts of SOS is suppressed. A high detection sensitivity associated with the stability of sulfate half-esters was achieved for the cesium salt of SOS using positive-ion detection. Finally, the cesium salt of chondroitin sulfate A disaccharide was successfully analyzed using UV-MALDI-TOFMS. 相似文献
107.
Wolff JJ Amster IJ Chi L Linhardt RJ 《Journal of the American Society for Mass Spectrometry》2007,18(2):234-244
The first application of electron detachment dissociation (EDD) to carbohydrates is presented. The structural characterization
of glycosaminoglycan (GAG) oligosaccharides by mass spectrometry is a longstanding problem because of the lability of these
acidic, polysulfated carbohydrates. Doubly-charged negative ions of four GAG tetrasaccharides are examined by EDD, collisionally
activated dissociation (CAD), and infrared multiphoton dissociation (IRMPD). EDD is found to produce information-rich mass
spectra with both cross ring and glycosidic cleavage product ions. In contrast, most of the product ions produced by CAD and
IRMPD result from glycosidic cleavage. EDD shows great potential as a tool for locating the sites of sulfation and other modifications
in glycosaminoglycan oligosaccharides. 相似文献
108.
Wolff JJ Laremore TN Busch AM Linhardt RJ Amster IJ 《Journal of the American Society for Mass Spectrometry》2008,19(2):294-304
The structural characterization of glycosaminoglycans (GAG) oligosaccharides has been a long-standing challenge in the field of mass spectrometry. In this work, we present the application of electron detachment dissociation (EDD) Fourier transform mass spectrometry to the analysis of dermatan sulfate (DS) oligosaccharides up to 10 residues long. The EDD mass spectra of DS oligosaccharides were compared with their infrared multiphoton dissociation (IRMPD) mass spectra. EDD produces more abundant fragmentation than IRMPD with far less loss of SO3 from labile sulfate modifications. EDD cleaves all glycosidic bonds, yielding both conventional glycosidic bond fragmentation as well as satellite peaks resulting from the additional loss of 1 or 2 hydrogen atoms. EDD also yields more cross-ring fragmentation than IRMPD. For EDD, abundant cross-ring fragmentation in the form of A- and X-ions is observed, with 1,5Xn cleavages occurring for all IdoA residues and many of the GalNAc4S residues, except at the reducing and nonreducing ends. In contrast, IRMPD produces only A-type cross-ring fragmentation for long oligosaccharides (dp6-dp10). As all the structurally informative fragment ions observed by IRMPD appear as a subset of the peaks found in the EDD mass spectrum, EDD shows great potential for the characterization of GAG oligosaccharides using a single tandem mass spectrometry experiment. 相似文献
109.
Deling Shi Peng He Yuefan Song Shuihong Cheng Robert J. Linhardt Jonathan S. Dordick Lianli Chi Fuming Zhang 《Molecules (Basel, Switzerland)》2022,27(18)
Monkeypox virus (MPXV), a member of the Orthopoxvirus genus, has begun to spread into many countries worldwide. While the prevalence of monkeypox in Central and Western Africa is well-known, the recent rise in the number of cases spread through intimate personal contact, particularly in the United States, poses a grave international threat. Previous studies have shown that cell-surface heparan sulfate (HS) is important for vaccinia virus (VACV) infection, particularly the binding of VACV A27, which appears to mediate the binding of virus to cellular HS. Some other glycosaminoglycans (GAGs) also bind to proteins on Orthopoxviruses. In this study, by using surface plasmon resonance, we demonstrated that MPXV A29 protein (a homolog of VACV A27) binds to GAGs including heparin and chondroitin sulfate/dermatan sulfate. The negative charges on GAGs are important for GAG–MPXV A29 interaction. GAG analogs, pentosan polysulfate and mucopolysaccharide polysulfate, show strong inhibition of MPXV A29–heparin interaction. A detailed understanding on the molecular interactions involved in this disease should accelerate the development of therapeutics and drugs for the treatment of MPXV. 相似文献
110.