Fast atom bombardment mass characterized

The treatment of sucrose with anhydrous HF89 results in the formation of a complex mixture of pseudooligo- and poly-saccharides up to dp 14, which were detected by fast-atom-bombardment mass spectrometry (FABMS). Some of the smaller products were isolated and identified by comparison with the known compounds prepared86 88 a-D-Fru/-1,2 2,1 -p-D-Fru/j (1), either free or variously glucosylated, was a major product, and this is in accord with the known stability of the compound. The mechanism of formation of the products in the case of sucrose involves preliminary condensation of two fructose residues. The resultant dianhydride is then glucosylated by glucopyranosyl cation.89 The characterization of this type of compound was an important step because it has permitted an increased understanding of the chemical nature of caramels. 

While the molecular masses of expanded [n]pericyclines 82,83,122 can easily be determined by GC-MS analysis, higher dehydrocyclooligomers fail to vaporize sufficiently [7]. Fast atom bombardment mass spectometry (FAB-MS) had to be applied for the characterization of the acetal-protected expanded pericyclinones 123-126 and 176 [39]. Attempts to determine the molecular masses of the... 

Reports of depolymerization studies carried out by Semiyen and co-workers at the University of York, UK, typically used much longer reaction times (24-72 h) for the depolymerization of PET [27], This group also reported that the titanates were ineffective catalysts for depolymerization, but it is not known whether measures to prevent titanate hydrolysis were taken. The York group also reported that the relative proportions of cyclic oligomers (trimer, tetramer, etc.) altered as the dilution ratio was changed. Similar results were seen with PBT. They have also reported fast-atom bombardment mass spectrometry (FAB-MS), LC-MS, GPC and X-ray crystallography data. The most recent work reports characterization of the cyclic oligomers from six ester and ether ester systems [29],... 

The average DS as determined by these methods provides only the simplest characterization of these derivatives, and further analysis was necessary to characterize the mixture of SBE bands of different levels of substitution. Due to the presence of the anionic sulfonate substituent, it is possible to use capillary electrophoresis (23), to separate the SBE-CD substitution bands and to characterize the fingerprint of the composition (Fig. 10). Anion exchange chromatography (24) was utilized to isolate separate substitution bands (mono- to deca-derivatives) that were subsequently identified by NMR and fast atom bombardment mass spectroscopy (FAB-MS). 

V. Kovacik, J. Hirsch, P. Kovac, W. Heerma, J. Thomas-Oates, and J. Haverkamp, Oligosaccharide characterization using collision-induced dissociation fast atom bombardment mass spectrometry Evidence for internal monosaccharide residue loss, J. Mass Spectrom., 30 (1995) 949-958. 

Single-crystal X-ray crystallography remains the only definitive technique for the structural characterization of heteronuclear gold cluster compounds, although other techniques, in particular Mossbauer, NMR, IR, and fast atom bombardment mass spectroscopies (FABMS), have yielded valuable information, especially concerning the nature of these species in solution. Electron spectroscopy, which has proved to be of great value in the identification of homonuclear gold cluster compounds (210) has received little attention by workers in this area,... 

The following sections summarize the applications of fast atom bombardment mass spectrometry, Mossbauer and NMR spectroscopies, and single-crystal X-ray diffraction studies in the characterization of het-eronuclear gold cluster compounds. 

Fast atom bombardment mass spectroscopy has proved to be most useful when applied to the characterization of heteronuclear gold cluster compounds containing hydride ligands (137,149,155). Characterization is aided by the observation that peaks are invariably present in the spectrum corresponding to ions that contain all of the hydride... 

Fast atom bombardment-mass spectrometry has been used to a limited extent in characterizing sphingomyelin. In a thioglycerol matrix, the following major ions were detected MH+, 731 M-28, 703 m/z 239, CH3(CH2)12CH=CH—CH+ m/z 184, Ophosphocholine (Dr. S. Weintraub, personal communication). 

In conclusion, I hope that I have shown that fast-atom bombardment mass spectrometry is a potentially useful tool for the synthetic chemist working in many areas of inorganic, organometallic, and coordination chemistry. In addition, as further fundamental research is done in the field with these applications in mind, the technique should become as routine as IR or NMR. Combined with developments in high-resolution NMR of solids, FAB should provide particularly useful data on supported catalytic reactions. Certainly FAB and the other complementary mass spectrometric techniques, mentioned in less detail, constitute a major way of quickly characterizing new compounds. 

Several non-volatile ionic complexes of As and Sb have been characterized by fast atom bombardment mass spectrometry (Table 12). The mass spectrum of 53 (a mixture of 3-nitrobenzyl alcohol with CH2CI2 was used as the matrix) exhibits (M -I- BF2), M, (M - 2CO)- -, CpFe(CO)2 +, Cp2Fe+ and Bi-" ions ... 

W. L. Roberts, S. Santikam, V. N. Reinhold, and T. L. Rosenberry, Structural characterization of the glycoinositol phospholipid membrane anchor of human erythrocyte acetylcholinesterase by fast atom bombardment mass spectrometry,./. Biol. Chem., 263 (1988) 18776—18784. 

Mass spectrometry can give valuable information on the structural details of Sn(II) heterometallic derivatives, subject to stability with respect to the disproportionation reaction in the vapor phase. The mass spectral results demonstrate that fast atom bombardment mass spectrometry (FARMS) could find immense applications in the characterization of heterometallic derivatives, particularly of non-volatile, high molecular weight compounds, such as those of tin. 

Mass Spectrom 8 169, 1994 (b) AM Bradford, RJ Waugh, JH Bowie. Characterization of underivatized tetrapeptides by negative-ion fast-atom bombardment mass spectrometry. Rapid Commun Mass Spectrom 9 677-685,1995 (c) ST Steinbomer, JH Bowie. A comparison of the positive- and negative-ion mass spectra of bio-active peptides from the dorsal secretion of the Australian Red Tree frog Iitoria rubella. Rapid Commun Mass Spectrom 10 1243—1247,1996. 

K McMellop, W Davidson, G Hansen, D Freeman, N Pallai. The characterization of crude products from solid-phase peptide synthesis by v-HPLC/fast atom bombardment mass spectrometry. Peptide research 4 40-46, 1991. 

Hudson, H.R., Matthews, R.W., McPartlin, M., Pryce, M.A., and Shode, O.O.. Quasiphosphonium intermediates. Part 7. The preparation of trinorborn-l-yl phosphite and its reactions with halogeno compounds. Stable intermediates of the Arbuzov and Perkow reactions and then sU uctural characterization by X-ray diffraction, NMR spectroscopy, and fast-atom-bombardment mass spectrometry, J. Chem. Soc., Perkin Trans. 2, 1433, 1993. 

Ganong, B. R., Loomis, C. R., Hannun, Y. A., Bell, R. M. (1986). Specificity and mechanism of protein kinase C activation by sn-l,2-diacylglycerols. Proc. Natl. Acad. Sci. USA 83,1184-1188. Gross, R. W. (1984). High plasmalogen and arachidonic acid content of canine myocardial sarcolemma a fast atom bombardment mass spectroscc ic and gas chromatography-mass spectroscopic characterization. Biochemistry 23,158-165. 

LBI Martin, AF Schreiner, RB van Breemen. Characterization of cisplatin adducts of oligonucleotides by fast atom bombardment mass spectrometry. Anal Biochem 193 6, 1991. 

All of these complexes were characterized by multinuclear NMR ( H, C, "B, Hg) and fast atom bombardment mass spectrometry (FAB/MS). Monoanion complexes (8) and (9) form dianion complexes (11) and (12), respectively, on further treatment with the respective halides <92JA380>. Both monoanion and dianion complexes can undergo metathesis with [As(QH4)4]Cl to form products (13) and (14), respectively <91AG(E)1507,92JA380>. Uncomplexed cyclotetramer (1) was extracted from its iodide ion complexes (8) and (11) by Ag(OAc) in ethanol. The same reaction from bromide and iodide complexes resulted in incomplete extraction of host tetramer <92AG(E)893>. Uncomplexed host macrocycles (1) and (3) were characterized by H, C, and B NMR <92AG(E)893,93JAI93). 

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