Oxolane Ammonium Salts (Muscarine-Like)-Synthesis and Microbiological Activity.

Commercially available 2-deoxy-D-ribose was used to synthesize the appropriate oxolane derivative-(2,3)-2-(hydroxymethyl)oxolan-3-ol-by reduction and dehydration/cyclization in an acidic aqueous solution. Its monotosyl derivative, as a result of the quaternization reaction, allowed us to obtain eight new muscarine-type derivatives containing a quaternary nitrogen atom and a hydroxyl group linked to the oxolane ring. Their structure was fully confirmed by the results of NMR, MS and IR analyses.

Hydrazinolysis Products of Selected Sugar Lactones-Crystal Structure and Microbiological Activity.

Commercially available lactones, as well as those synthesized by us, turned out to be good substrates for the synthesis of sugar hydrazides. The exception was L-ascorbic acid, whose hydrazinolysis led to the formation of a hydrazinium salt, not the hydrazide as expected. The structure of all compounds was confirmed by NMR and X-ray analyses.

Synthesis, Antimicrobial and Mutagenic Activity of a New Class of d-Xylopyranosides.

Eight -[2-(2',3',4'-tri--acetyl-α/β-d-xylopyranosyloxy)ethyl]ammonium bromides, a new class of d-xylopyranosides containing a quaternary ammonium aglycone, were obtained. Their complete structure was confirmed using NMR spectroscopy (H, C, COSY and HSQC) and high-resolution mass spectrometry (HRMS). An antimicrobial activity against fungi (, ) and bacteria (, ) and a mutagenic Ames test with TA 98 strain were performed for the obtained compounds.

Different Schiff Bases-Structure, Importance and Classification.

Schiff bases are a vast group of compounds characterized by the presence of a double bond linking carbon and nitrogen atoms, the versatility of which is generated in the many ways to combine a variety of alkyl or aryl substituents. Compounds of this type are both found in nature and synthesized in the laboratory. For years, Schiff bases have been greatly inspiring to many chemists and biochemists.

NMR and MD Analysis of the Bonding Interaction of Vancomycin with Muramyl Pentapeptide.

The article describes an NMR spectroscopy study of interactions between vancomycin and a muramyl pentapeptide in two complexes: vancomycin and a native muramyl pentapeptide ended with D-alanine (MPP-D-Ala), and vancomycin and a modified muramyl pentapeptide ended with D-serine (MPP-D-Ser). The measurements were made in a 9:1 mixture of HO and DO. The obtained results confirmed the presence of hydrogen bonds previously described in the literature.

The Quaternization Reaction of 5--Sulfonates of Methyl 2,3--Isopropylidene--D-Ribofuranoside With Selected Heterocyclic and Aliphatic Amines.

The synthesis of -((methyl 5-deoxy-2,3--isopropylidene--D-ribofuranoside)-5-yl)ammonium salts are presented. To determine the effect of the nucleophile type and outgoing group on the quaternization reaction, selected aliphatic and heterocyclic aromatic amines reacted with: methyl 2,3--isopropylidene-5--tosyl--D-ribofuranoside or methyl 2,3--isopropylidene-5--mesyl--D-ribofuranoside or methyl 2,3--isopropylidene-5--triflyl--D-ribofuranoside were performed on a micro scale. High-resolution H- and C-NMR spectral data for all new compounds were recorded.

Molecular modeling of Gram-positive bacteria peptidoglycan layer, selected glycopeptide antibiotics and vancomycin derivatives modified with sugar moieties.

Proper understanding of the mechanisms of binding to Gram-positive bacteria cell wall layers-especially to the peptidoglycan (PG) layer, seems to be crucial for proper development of new drug candidates which are effective against these bacteria. In this work we have constructed two different models of the Gram-positive bacteria PG layer: the layered and the scaffold models. PG conformational changes during geometry optimization, models relaxation, and molecular dynamics were described and discussed.

Structure and properties of the exopolysaccharides produced by Pseudomonas mutabilis T6 and P. mutabilis ATCC 31014.

This paper presents a study on the purification, primary structure, and rheological properties of exopolysaccharides isolated from cultures of Pseudomonas mutabilis T6 and P. mutabilis ATCC 31014. Both polymers are exopolysaccharides of D-mannose.

Glycosylation of allyl 2-acetamido-4,6-O-benzylidene-2-deoxy-alpha-D-glucopyranoside with bulky substituted glycosyl donors.

Glycosylation of allyl 2-acetamido-4,6-O-benzylidene-2-deoxy-alpha-D-glucopyranoside with bulky substituted glycosyl donors leads to the formation of derivatives of the disaccharide alpha-D-Glc-(1-->3)-d-GlcNAc with different yields.

Synthesis of cis-(1-->3)-glycosides of allyl 2-acetamido-4,6-O-benzylidene-2-deoxy-alpha-D-glucopyranoside.

Syntheses of allyl 2,3,4-tri-O-benzyl-alpha-D-gluco- and D-galactopyranosyluronate-(1-->3)-2-acetamido-4,6-O-benzylidene-2-deoxy-alpha-D-glucopyranoside via oxidation of the hydroxymethyl group of allyl 2,3,4-tri-O-benzyl-alpha-D-gluco- and D-galactopyranosyl-(1-->3)-2-acetamido-4,6-O-benzylidene-2-deoxy-alpha-D-glucopyranoside under Jones conditions are described. Structures of the title compounds were confirmed by (1)H and (13)C NMR spectroscopy.

Vitamin C metabolomic mapping in experimental diabetes with 6-deoxy-6-fluoro-ascorbic acid and high resolution 19F-nuclear magnetic resonance spectroscopy.

Metabolomic mapping is an emerging discipline geared at providing information on a large number of metabolites as a complement to genomics and proteomics. Here we have probed ascorbic acid homeostasis and degradation in diabetes using 6-deoxy-6-fluoro ascorbic acid (F-ASA) and 750 MHz (19)F-nuclear magnetic resonance (NMR) spectroscopy with proton decoupling In vitro, Cu(2+)-mediated degradation of F-ASA revealed the formation of 4 major stable degradation products at 24 hours. However, when normal or diabetics rats were injected with F-ASA intraperitoneally (IP) for 4 days, up to 20 fluorine-labeled compounds were observed in the urine.

Vitamin C metabolomic mapping in the lens with 6-deoxy-6-fluoro-ascorbic acid and high-resolution 19F-NMR spectroscopy.

Purpose: Metabolomics, or metabolic profiling, is an emerging discipline geared to providing information on a large number of metabolites, as a complement to genomics and proteomics. In the current study, a fluorine-labeled derivative of ascorbic acid (F-ASA), a major antioxidant- and UV-trapping molecule in the aqueous humor and the lens, was used to investigate the extent to which the lens accumulates potentially toxic degradation products of vitamin C.

Methods: Human lens epithelial cells (HLE-B3) and rat lenses were exposed to hyperglycemic or oxidative stress in vitro or in vivo and probed for accumulation of F-ASA, fluoro-dehydroascorbate (F-DHA), fluoro-2,3-diketogulonate (F-DKG), and their degradation products in protein-free extracts, by proton-decoupled 750-MHz (19)F-nuclear magnetic resonance (NMR) spectroscopy.

Side products of glycosidation with selected 2-acetamido-2-deoxy-D-glucopyranosides.

Allyl 2-acetamido-4,6-O-benzylidene-2-deoxy-3-O-formyl-alpha-D-glucopyranoside, N-acetyl-2,3,4-tri-O-acetyl-L-fucopyranosylamine and products of O-acetyl group migration were found as side products during glycosidation of selected 2-acetamido-2-deoxy-D-glucopyranosides.

The solvent-free thermal dehydration of hexitols on zeolites.

Dehydration of galactitol, D-glucitol and D-mannitol at high temperature in the presence of molecular sieves without solvent under an argon atmosphere is described. Cyclodehydration products with retention or inversion of the configuration at asymmetric carbon atoms, were observed. Reaction of galactitol yielded racemic 1,4-anhydrogalactitol in a first step and then racemic 1,4:3,6-dianhydroiditol.

The Transformation Mechanism of 3,4,6-Tri-O-acetyl-1,5-anhydro-2-deoxy-D-arabino-hex-1-enitol in Water.

Heating of 3,4,6-tri-O-acetyl-1,5-anhydro-2-deoxy-D-arabino-hex-1-enitol (per-O-acetyl-D-glucal) in water leads to a mixture of unsaturated compounds with cyclic as well as open-chain structures. The mixture obtained was analyzed by the CGC method. The experimental findings were employed to model the mechanism of the transformation studied.