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Ibuprofen-tyrosine (Val-Tyr, Val-Tyr-Val) interactions. Theoretical and experimental studies

Kowalska-Baron A., Brychtova M., Petrovic I., Passos Sene I., Quinones P., Sogorkova J.

Biotechnology and Food Science

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2011

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Vol. 75, nr 2

15-26

EN

In this work, the interactions between ibuprofen and tyrosine as well selected tyrosine-containing oligopeptides (Val-Tyr, Val-Tyr-Val) have been studied using both experimental (absorption and fluorescence spectroscopy) and theoretical (the PM3 method) techniques. The experimentally obtained values of association constant together with free Gibbs energy of association for the studied tyrosine-ibuprofen and Val- Tyr-; Val-Tyr-Val-ibuprofen complexes have been determined. The obtained results indicated that the mechanism of action of ibuprofen is most probably based on the hydrogen bonding interaction which involves hydroxyl group of tyrosine.

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Two Independent Hydrogen Bonded Complexes of Bis(1-piperidiniumacetate) Hydrochloride in the Crystal and in the PM3 Optimized Structure

Dega-Szafran Z., Petryna M., Dutkiewicz G., Kosturkiewicz Z.

Polish Journal of Chemistry

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2003

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Vol. 77 / nr 11

1501-1512

EN

Bis(1-piperidiniumacetate) hydrochloride, (PAA)2H+źCl-, has been synthesized and its structure solved by X-ray diffraction. The crystals belong to the triclinic system with two symmetrically independent hydrogen bonded complexes, denoted A and B, at two different inversion centers. The compound crystallizes in the space group P1 with a = 8.559(1), b = 9.625(1), c = 11.441(1) A, _ = 74.85(1)°, _= 68.22(1)°, _ = 84.10(1)°, Z = 2, R = 0.036. Each complex consists of two 1-piperidiniumacetate moieties. Four 1-piperidiniumacetates, as zwitterions, are held together by a network of hydrogen bonds of the types OźźźHźźźO (2.462(3) and 2.463(3) A), N-HźźźO (2.755(2) A) and N-HźźźCl (3.167(2)A). Both N-H atoms in complex A interact with chlorine anions. A number of week C-HźźźCl contacts stabilize the three-dimensional crystal structure. In the isolated molecule of (PAA)2H+źCl- optimized by the PM3 method, there also are two independent hydrogen bonded complexes. In complex A the neutral form of 1-piperidineacetic acid interacts with its anionic form, while in complex B the 1-piperidiniumacetic acid, as a cation, forms a hydrogen bond with its zwitterionic form. FTIR spectrum of bis(1-piperidiniumacetate) hydrochloride has been analyzed and discussed.

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Experimental and Theoretical Studies on Pyrolysis of O-Acetyl Derivatives of beta-phenylcinnamaldehyde and Benzaldehyde Oximes

Mohamed M., Siedlecka M., Suwiński J.

Polish Journal of Chemistry

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2003

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Vol. 77 / nr 5

577-590

EN

[ReBr3(py)3]0.42[ReBr2(NO)(py)3]0.58 (1), trans-[ReBr4(OPPh3)2] (2), [ReBr(NO)(dppe)2]Br (3) and orthorhombic polymorph of mer-cis- [Re(NO)Br3(OPPh3)2] (4) complexes have been synthesized by reactions of monoclinic polymorph of mer-cis-[Re(NO)Br3(OPPh3)2] with pyridine, bis(diphenylophosphino) ethane, 2,2_-bipyridine, 1,10-phenanthroline. The NO group in 1 and 4 is coordinated in a linear way. Due to nitrosyl/bromine compositional disorder, the shortening of Re-NO distance [1.68(5) A] and the elongation of N-O bond length [1.38(10) A] are observed in1. The N-O bond length in 4 is extremely short [0.94(1) A], which results probably from steric interactions of two mutually cis OPPh3 molecules and a large discrepancy of Re-O-P angle values.

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Excited State Intramolecular Proton Transfer in 9-Oxo-9,10-dihydro-acridine-4-carboxylic Acid. photophysical and Computational studies

Sobczyk M., Szymańska A., Wiczk W., Łankiewicz L., Karolczak J., Rak J.

Polish Journal of Chemistry

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2002

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Vol. 76 / nr 9

1263-1269

EN

9-Oxo-9,10-dihydro-acridine-4-carboxylic acid in both methanol and acetonitrile possesses a dual fluorescence and complex fluorescence intensity decay, whereas 9-oxo- 9,10-dihydro-acridine-2-carboxylic acid shows only one emission band and monoexponential fluorescence intensity decay. Theoretical calculations, using a semiempirical PM3 method, confirm, in the case of 9-oxo-9,10-dihydro-acridine-4-carboxylic acid, the excited state intramolecular proton transfer process from nitrogen atom to the oxygen of carbonyl of the carboxylic group.