A conformational analysis with the semiempirical PM3 method was performed for the (3S,5R,6R)-6-acetylamidopenicillanic acid. 47 distinct conformers were found within 11.36 kcal/mol. Dependence of some electronic properties of these conformers (HOMO and LUMO energies, dipole moment, νmin frequence of the minimum vibration, νMAX frequence of the maximum vibration, zero point vibration energy (ZPVE) and charge densities on atoms S1, N4, N14, O8, O12,

Polymers become more important in everyday life. Although extremely useful in their life cycle, polymers become long-term pollutants. Worldwide, along the increased research in the environmental field, one can obviously observe a keen interest into new biodegradable and biocompatible plastic materials. This paper presents the synthesis and characterization of a new class of biodegradable copolymers based on carbohydrates. An oligomer was synthesized

Thioglycosides of mercaptotriazoles in the piranose and furanose series were oxidized to sulfones by a mild and efficient oxidation method, using KMnO4/CuSO4 in acetonitrile. The structural assignement of the newly synthesized compounds was based on their 1H, 13C-NMR, I.R. and mass spectra.

The synthesis of a new symmetric disazo direct dye containing the non{carcinogenic 4,4 0 -diaminobenzanilide as the middle component and salicylic acid as the coupling component is presented. The synthesized dye is an analog of the benzidine based dye C. I. Direct Yellow 1 (C. I. 22,250) and was analyzed by thin layer chromatography (TLC), electronic spectra (VIS) and mass spectroscopy (FAB-MS). The coloristic and fastness properties of the synthesized

In this paper the authors present the experimental results of the thermal analysis of heteropolynuclear coordination compound [Co2NiL3(OH)3(H2O)3]n, where L is lactate anion, obtained by a new method, through the reaction of 1,2-propanediol with M(NO3)2·6H2O (M: Co, Ni). The reaction between 1,2-propanediol and M(NO3)2·6H2O (M: Co, Ni) occurs with the oxidation of 1,2-propanediol to the lactate anion (L), coordinated to M(II). The thermal properties

We report on a novel strategy for identification of specific sulfation motifs in chondroitin/ dermatan sulfate (CS/DS) chain derived from decorin (Dcn), based on enzyme cleavage and multistage MS (MSn). Released CS/DS chains were digested with chondroitin B and in parallel with AC I lyases to obtain oligosaccharides of known hexuronic acid (HexA) epimerization. The depolymerized chains were separated by gel filtration, and collected di- and hexasaccharides

Gangliosides (GGs), a large group of sialylated glycosphingolipids, are considered biomarkers of human brain development, aging, and certain diseases. Determination of individual GG components in complex mixtures extracted from human brain represents a fundamental prerequisite for correlating their specificity with the specialized function of each brain area. In context of modern glycomics, detailed investigation of GG expression and structure in

We developed a straightforward approach for high-throughput top-down glycolipidomics based on fully automated chipnanoelectrospray (nanoESI) high-capacity ion trap (HCT) multistage mass spectrometry (MSn) by collision-induced dissociation (CID) in the negative ion mode. The method was optimized and tested on a polysialylated ganglioside fraction (GT1b), which was profiled by MS1 and sequenced in tandem MS up to MS6 in the same experiment. Screening

Chondroitin sulfate (CS) and dermatan sulfate (DS) glycosaminoglycans display variability of sulfation in their constituent disaccharide repeats during chain elongation. Since a large proportion of the extracellular matrix of the central nervous system (CNS) is composed of proteoglycans, CS/DS disaccharide degree and profile of sulfation play important roles in the functional diversity of neurons, brain development, and some of its pathological states.

We report here on a preliminary investigation of ganglioside composition and structure in human hemangioma, a benign tumor in the frontal cortex (HFC) in comparison to normal frontal cortex (NFC) tissue using for the first time advanced mass spectrometric methods based on fully automated chip-nanoelectrospray (nanoESI) high-capacity ion trap (HCT) and collision-induced dissociation (CID). The high ionization efficiency, sensitivity and reproducibility