MALDI-TOF MS analysis of a library of polymerizable cyclodextrin derivatives

CD Oxyanions as a Tool for Synthesis of Highly Anionic Cyclodextrin Polymers

Water soluble highly anionic β-cyclodextrin-based polymers were synthesized by reaction between cyclodextrin oxyanion and pyromellitic anhydride. The synthesis method utilizes activation hydroxyl groups in anhydrous glucopyranosyl units (AGU) in the DMF solution with the use of NaH. In these conditions, like in the case of the cyclodextrin reactions in the highly alkaline media, there is a nucleophilic substitution of difunctional compounds, which develops a polymer network with various cyclodextrin substitution. Different molar ratios of the reagents were investigated in terms of molecular size, chemical structure and water solubility of the polymers. The separation of the polymer due to particle size by ultrafiltration process and HPSEC-MALLS-RI and MALDI-TOF MS measurements for molecular mass analysis were employed. The IR, H NMR, SEM, DSC and TG measurements were taken for the structural characterization of the polymers. Additionally, the solubility test and metal ion complexation processes were also investigated in a wide range of pH. These polymers could be used in several areas such as: improving the aqueous solubility of poor water-soluble molecules, removing heavy metals from waste water, protecting degradable substances or synthesizing new drug delivery systems.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update covering the period 1999-2000

This review describes the use of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry for the analysis of carbohydrates and glycoconjugates and continues coverage of the field from the previous review published in 1999 (D. J. Harvey, Matrix-assisted laser desorption/ionization mass spectrometry of carbohydrates, 1999, Mass Spectrom Rev, 18:349-451) for the period 1999-2000. As MALDI mass spectrometry is acquiring the status of a mature technique in this field, there has been a greater emphasis on applications rather than to method development as opposed to the previous review. The present review covers applications to plant-derived carbohydrates, N- and O-linked glycans from glycoproteins, glycated proteins, mucins, glycosaminoglycans, bacterial glycolipids, glycosphingolipids, glycoglycerolipids and related compounds, and glycosides. Applications of MALDI mass spectrometry to the study of enzymes acting on carbohydrates (glycosyltransferases and glycosidases) and to the synthesis of carbohydrates, are also covered.

Effects of polymerization initiator complexation in methacrylated β-cyclodextrin formulations

OBJECTIVES

Methacrylated beta-cyclodextrin (MCD) is a candidate dental monomer that can complex molecules within its hydrophobic cavity. This study determined the effects of complexation of polymerization initiators such as camphorquinone (CQ) and ethyl-4-dimethylaminobenzoate (4E) with MCD on the flexural strength (FS) and degree of conversion (DC) of resulting dental composite formulations.

METHODS

Complexation of CQ and 4E with MCD was studied by thin layer chromatography. A mass fraction of 44% 2-hydroxyethylmethacrylate or triethyleneglycoldimethacrylate was mixed separately with a mass fraction of 56% MCD to produce a workable formulation. The mixture was activated with varied amounts of CQ and 4E. One part by mass of the activated resin formulation was mixed with three parts by mass of glass filler. Specimens for FS were prepared by filling molds with composites and curing for 2 min. The cured specimens were immersed in 37 degrees C water for 24 h and FS was measured with an Instron machine at a crosshead speed of 0.5 mm/min. DC in MCD-based resin formulations was measured with a differential photocalorimeter under nitrogen.

RESULTS

MCD appears to form inclusion complexes with CQ and 4E. As a result, FS and DC of MCD-based composites vary significantly as a function of the concentration of polymerization initiators used in the formulations.

SIGNIFICANCE

Complexation of polymerization initiators with MCD can influence the FS and DC in MCD-based dental formulations and should be taken into consideration when evaluating MCD as a dental monomer.

Current literature in mass spectrometry

In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of mass spectrometry. Each bibliography is divided into 11 sections: 1 Books, Reviews & Symposia; 2 Instrumental Techniques & Methods; 3 Gas Phase Ion Chemistry; 4 Biology/Biochemistry: Amino Acids, Peptides & Proteins; Carbohydrates; Lipids; Nucleic Acids; 5 Pharmacology/Toxicology; 6 Natural Products; 7 Analysis of Organic Compounds; 8 Analysis of Inorganics/Organometallics; 9 Surface Analysis; 10 Environmental Analysis; 11 Elemental Analysis. Within each section, articles are listed in alphabetical order with respect to author (3 Weeks journals - Search completed at 28th. June 2000)