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Otrzymywanie i właściwości biologiczne racemicznych i optycznie czynnych laktonów z pierścieniem aromatycznym w pozycji β

Gładkowski Witold

Wiadomości Chemiczne

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2023

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[Z] 77, 5-6

509--531

EN

Natural and synthetic lactones containing an aromatic ring exhibit a number of biological properties, e.g. antiproliferative, antifeedant or antimicrobial activity. This review deals with the synthesis and biological properties of lactones containing an aromatic substituent in the β-position of the lactone ring. The described group of compounds includes halolactones, hydroxylactones, unsaturated lactones and products of reductive dehalogenation of iodolactones. In addition to chemical transformations, biotechnological methods for obtaining optically active lactones have also been described, including the use of lipases in the chemoenzymatic pathway leading to the production of halolactones, kinetic separation of hydroxylactones in the process of enzymatic transesterification, microbial hydrolytic dehalogenation of iodolactones and enantioselective hydrolysis of the lactone ring. The biological activity of the obtained β-aryllactones was also briefly characterized.

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Określanie konfiguracji absolutnej za pomocą magnetycznego rezonansu jądrowego

Kołodziejska R., Jasińska L., Karczmarska A., Dramiński M.

Wiadomości Chemiczne

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2008

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[Z] 62, 7-8

709-732

EN

In relation to a very limited scale of tolerance of organisms to different geometrical isomers it has been imperative to invent a method which would enable a precise and fast evaluation of a spatial structure of optically active compounds. Using a spectroscopic method of nuclear magnetic resonance (NMR) proved to be an excellent solution. In order to define an absolute configuration by means of NMR, the enantiomeric mixture must be transformed into diastereoisomeric one by adding chiral auxiliary substituents. We distinguish three types of chiral auxiliary reagents: CDAs (chiral derivatizing agents), CSAs (chiral solvating agents), CLSRs (chiral lanthanide shift reagents). Chiral derivatizing agents are the most frequently used in analyses. The condensation reaction of an auxiliary compound with enantiomer may be single or double derivatization. In case of a double derivatization, 1H NMR spectra of two diastereoisomers obtained as a result of condensation of (R)- and (S)-CDAs with the substrates are compared. The changes in the chemical shifts of the substituents L_1 (the most bulky substituent) and L_2 (the least bulky substituent) asymmetric carbon of the substrate in the two derivatives (R)- and (S)-CDAs is defined as ?[delta delta]^RS. The [delta]^RS value is the difference between the chemical shift in the (R)-CDAs derivative ([delta](R)) and (S)-CDAs derivative ([delta](S)) for the substituents L_1 ([delta delta]^RSL_1) and L_2 ([delta delta]^RSL2) (Figure 2). In case of a single derivatization, the tested enantiomer is combined with only one enantiomer ((R)- or (S)-CDA). In the single derivatization [delta delta]^AR ([delta delta]^AR = [delta](A)-[delta](R)) is the difference in the chemical shifts of the substituents L_1 and L_2 of a derivative and a free substrate (Figure 3) [1]. Among these auxiliary reagents are MPA (methoxyphenylacetic acid), MTPA (methoxytrifluoromethylphenylacetic acid), 9-AMA (9-anthrylmethoxyacetic acid), BPG (boc-phenylglycine), 9-AHA (ethyl 2-(9-anthryl)-2-hydroxyacetate), PGME (phenylglycine methyl ester), and PGDA (phenylglycine dimethyl amide). These reagents are currently being used to determine the absolute configuration of primary alcohols (Figure 4), secondary alcohols (Figure 5), tertiary alcohols, diols [2-5], triols [6], primary amines (Figure 6, 7), secondary amines (Figure 8), and carboxylic acids (Figure 9). Other methods of determining absolute configuration such as HPLC-NMR or "mix and shake" method are currently investigated - HPLC-NMR method allows determining the absolute configuration of enantiomeric mixture as well as a pure enantiomer, the use of semipreparative column allows to precisely distinguish the obtained derivatives, which undergo the spectroscopic analysis (Figure 11) [1]. The "mix and shake" method allows determining the absolute configuration in a few minutes and without any additional separation methods. The derivative/s is/are prepared by simply mixing a solid matrix-bond auxiliary reagent with a chiral substrate and NMR spectra of the resulting derivatives are obtained without any further manipulation (Figure 12) [7].

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Dimolybdenum Method for Determination of the Absolute Configuration of vic-Diols - Foundations and Developments

Górecki M., Kamińska A., Ruśkowska P., Suszczyńska A., Frelek J.

Polish Journal of Chemistry

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2006

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Vol. 80, nr 4

523-534

EN

A straightforward and versatile method for the determination of the absolute configuration of vic-diols is presented. The proposed method involves the in situ formation of chiral complexes of optically active vic-diols with the achiral dimolybdenum tetraacetate [Mo2(OAc)4] acting as an auxiliary chromophore. The resulting CD spectra are suitable for the assignment of absolute configuration, since the observed sign of Cotton effects arising within the d-d absorption bands of the metal cluster depends solely upon the chirality of the 1,2-diol ligands.An empirically based rule correlating a positive/negative helicity expressed by the O-C-C-O torsional angle with the sign of Cotton effects occurring in the 400-280 nm spectral range has been presented. The applicability of the rule is extended to sterically hindered sec/tert vic-diols.

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Determination of the Absolute Configuration of 2-Hydroxyglutaric Acid, 5-Oxoproline and Vigabatrin in Urine by Chiral Derivatization and 13C or 19F NMR

Bal D., Gryff-Keller A.

Polish Journal of Chemistry

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2006

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Vol. 80, nr 7

1021-1030

EN

Procedures for enantiomeric recognition of 2-hydroxyglutaric acid and 5-oxoproline - markers ofmetabolic diseases, and of vigabatrin - an antiepileptic drug, suitable for urine samples, have been elaborated. They rely upon derivatization of the metabolites with a chiral reagent; this is made without separation of these compounds from a biological sample. The diastereotopic metabolite derivatives are then distinguished using 13C or 19F NMR spectroscopy. This procedure is not so simple as one proposed previously, but, as opposite to the latter method, it seems to be unfailing and still not too complicated.

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Chrality Probing of Chlorotetrabutyratodiruthenium (II,III) Complexes with vic-amino Alcohols by Circular Dichroism Spectroscopy

Frelek J., Kamińska A., Pakulski Z., Szmigielski R., Priebe W.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 2

387-399

EN

The circular dichroism (CD) spectra of a variety of vic-amino alcohols in the presence of chlorotetrabutyratodiruthenium(II,III) as an auxiliary chromophore were measured in acetonitrile and chloroform. The method was tested in several model compounds containing acyclic and cyclic amino alcohols, and among them biologically important adrenergic drugs and amino sugars. The study demonstrated that the sign of the Cotton effects obtained is determined by the preferred helicity of the O-C-C-N unit in the chiral complex formed in situ. On this basis, a rule was formulated that correlates a positive (negative) sign of the O-C-C-N torsional angle with a positive (negative) Cotton effect arising around 350 nm and/or with negative (positive) signs of CD spectra bands occurring around 300 and 400 nm.

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Crystal and Molecular Structure of (-)-(S)- and (+)-(R)-Bromofosfamide

Karolak-Wojciechowska J., Wieczorek M., Grynkiewicz G., Kutner A.

Polish Journal of Chemistry

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1999

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Vol. 73, nr 11

1877-1885

EN

The crystal and molecular structures of (-)-(S)- and (+)-(R)-bromofosfamide were determined as a part of our research on therapeutically useful oxazaphosphorines. Both compounds crystallized in strictly enantiotropic crystals. Both sompound undergo partial decomposition during diffractometric exposition with emission of free bromine.