Biomedical subjects

Andrzej Temeriusz

Publications and source records attributed to Andrzej Temeriusz.

6 recordsLinked to original sources

PubMed2006

Crystal structure and solid-state 13C NMR analysis of N-o-, N-m- and N-p-nitrophenyl-2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosylamines, and their N-acetyl derivatives.

The X-ray diffraction analysis of N-o-nitrophenyl-2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosylamine (1), N-m-nitrophenyl-2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosylamines, N-p-nitrophenyl-2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosylamines, and their N-acetyl derivatives was performed. The sugar moieties always adopt (4)C1 conformations, however, due to crystal packing forces they are always slightly distorted. It was found that except N-acetyl, N-m-nitrophenyl-2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosylamine (5), none of the glucopyranosylamines studied in this paper form strong hydrogen bonds in the crystal lattice. Additionally, (5) crystallizes with a molecule of water, which occupies a special crystallographic position (on the twofold axis) and links two sugar molecules by hydrogen bonds. The CP MAS NMR spectra confirmed the presence of the intermolecular hydrogen bond involving the molecule of water in (5). Moreover, it was proved that in (1) an intramolecular hydrogen bond is formed between the glycosidic linkage and the nitro group.

Acetylation↗

PubMed2005

Crystal structure and solid-state 13C NMR analysis of N-p-nitrophenyl-alpha-D-ribopyranosylamine, N-p-nitrophenyl-alpha-D-xylopyranosylamine, and solid-state 13C NMR analysis of N-p-nitrophenyl-2,3,4-tri-O-acetyl-beta-D-lyxopyranosylamine and N-p-nitrophenyl-2,3,4-tri-O-acetyl-alpha-L-arabinopyranosylamine.

The X-ray diffraction analysis of N-p-nitrophenyl-alpha-D-ribopyranosylamine (1) and N-p-nitrophenyl-alpha-D-xylopyranosylamine (2) was performed. It was found that an independent part of the unit cell of compound 1 is formed by three molecules of sugar whereas the crystals of compound 2 have one molecule in the independent part of the crystal unit cell. Additionally, 1 crystallizes with one molecule of water. The solvent molecule forms an extensive hydrogen bond network with the hydroxyl groups of the sugar, and this efficiently stabilizes the crystal lattice. Contrary to 2, the sugar moieties of 1 adopt the 1C4 conformation. In the spectra of 2, N-p-nitrophenyl-2,3,4-tri-O-acetyl-beta-D-lyxopyranosylamine and N-p-nitrophenyl-2,3,4-tri-O-acetyl-alpha-L-arabinopyranosylamine the number of resonances does not exceed the number of carbon atoms in the molecules, thus indicating no polymorphism. In the spectrum of (1) the signals are split, confirming the presence of three independent molecules in the crystal unit cell.

Arabinose↗

PubMed2005

Synthesis of bis-(methyl 3,4,6-tri-O-acetyl-D-glucopyranosid-2-yl)-oxamides.

The synthesis of a new bis-(D-glucopyranosid-2-yl)oxamides via the key intermediate, N-acetyl N-(methyl 3,4,6-tri-O-acetyl-alpha-D-glucopyranosid-2-yl) oxamic acid chloride (2alpha) is described. Treatment of compound 2alpha with methyl 3,4,6-tri-O-acetyl-2-amino-2-deoxy-beta-D-glucopyranoside afforded N-(methyl 3,4,6-tri-O-acetyl-alpha-D-glucopyranosid-2-yl)-N'-(methyl 3,4,6-tri-O-acetyl-beta-D-glucopyranosid-2-yl)-oxamide. Reaction of 2alpha with 1,2-diaminoethane afforded 1,2-bis-[N,N'-(methyl 3',4',6'-tri-O-acetyl-alpha-D-glucopyranosid-2'-yl)]ethyloxamide as a main product, while 2-N-[N'-(methyl 3',4',6'-tri-O-acetyl-alpha-D-glucopyranosid-2'-yl)oxamide]-ethyl acetamide was formed as a side product. Reaction of 2alpha with 1,3-diamino-2-hydroxypropane gave only 1,3-bis-N,N-[N'-(methyl 3',4',6'-tri-O-acetyl-2'-deoxy-alpha-D-glucopyranosid-2'-yl)-oxamido]-2-propanol.

Carbohydrate Sequence↗

PubMed2005

Crystal structure and solid state 13C NMR analysis of nitrophenyl 2,3,4,6-tetra-O-acetyl-beta-D-gluco- and D-galactopyranosides.

The X-ray diffraction analysis of o-nitrophenyl 2,3,4,6-tetra-O-acetyl-beta-D-galactopyranoside (1), m-nitrophenyl 2,3,4,6-tetra-O-acetyl-beta-D-galactopyranoside, p-nitrophenyl 2,3,4,6-tetra-O-acetyl-beta-D-galactopyranoside and o-nitrophenyl 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranoside was performed. It was found that except in the case of 1, all other crystals have one molecule in the independent part of the crystal unit cell. The results support the opinion that the nitro group does not conjugate effectively with the phenyl ring. In the 13C CP MAS spectrum of 1 the signals are split, confirming the presence of two independent molecules. Similarly, the 13C CP MAS NMR spectrum of p-nitrophenyl-2,3,4,6-tetra-O-acetyl-beta-D-glucopyranoside indicated the presence of two non-equivalent molecules in the crystal unit. One of these molecules has more conformational freedom enabling rotation of the phenyl ring.

Acetylation↗

PubMed2003

Beta-cyclodextrin-based ferrocene-imprinted gold electrodes.

A new stepwise self-assembly procedure is described for the preparation of functional cyclodextrin-modified electrodes. The approach is based on the formation of alkanethiol/lipoylamide-beta-cyclodextrin monolayers with the thiol component responsible for blocking of the electrode surface and lipoylamide-beta-cyclodextrin molecules-for controlled opening of the access of the electroactive probe to the electrode. Functionalization of the electrode is achieved by means of a new cyclodextrin derivative-mono(6-deoxy-6-lipoylamide)-per-2,3,6-O-acetyl-beta-cyclodextrin-prepared in the peracetyl form and deacetylated directly on the electrode surface following the cyclodextrin self-assembly. The progress of deacetylation was monitored by the MALDI MS technique. Deacetylation caused opening of the active sites toward solution probes. The response toward ferrocene was found to be highly improved when ferrocene was added to the solution following self-assembly of cyclodextrin but prior to the thiol self-assembly step (imprinting method). The proposed synthesis and sequential monolayer formation scheme lead to well-organized and stable modified electrode surfaces with improved sensitivity toward solution species compared to other procedures of electrode modification with the cyclodextrin derivatives.

Algorithms↗

PubMed2003

Synthesis and solid state 13C and 1H NMR analysis of new oxamide derivatives of methyl 2-amino-2-deoxy-alpha-D-glucopyranoside and ester of amino acids or dipeptides.

The syntheses of new oxamide derivatives of methyl 2-amino-2-deoxy-alpha-D-glucopyranoside and amino acid or peptide esters are presented. The reaction of methyl 3,4,6-tri-O-acetyl-2-acetamido-2-deoxy-alpha-D-glucopyranoside and oxalyl chloride gave N-(methyl 3,4,6-tri-O-acetyl-2-deoxy-alpha-D-glucopyranosid-2-yl) oxamic acid chloride which on reaction with the ester of Gly, L-Ala, L-Phe, GlyGly, Gly-L-Phe and Gly-L-Ala afforded N-(methyl 3,4,6-tri-O-acetyl-2-deoxy-alpha-D-glucopyranosid-2-yl), N'-oxalyl-amino acid or dipeptide esters. The structure of the oxamides was studied using 1H, 13C NMR in solution and solid state.

Amino Acids↗