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1

Olfactory properties of enantiomers of undecan-x-ols (x = 2, 3) and their acetates

Gibka J., Gliński M.

Biotechnology and Food Science

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2014

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Vol. 78, nr 2

121--128

EN

Racemic undecan-x-ols (x = 2,3) used as starting materials in a biocatalysed enzymatic acylation with vinyl acetate in the presence of Novozym 435®. As result enantiomerically pure alcohols and their acetates have been obtained. The odours of each of the enantiomers have been compared with those of the racemic mixtures. Enantiomerically pure undecan-2-ols as well as their acetates have intense odours which differ in type, since their intensity is similar, the odour of each racemate comprises the odours of both enantiomers. Racemic undecan-3-ol has the odour of the R enantiomer only, because the opposite enantiomer is almost odourless. The odour of the racemic undec-3-yl acetate is faint with a fatty-soapy note despite of the fact that both enantiomers exhibit pleasant floral odours.

2

Lavandulol – biological activity and synthesis

Ciołak K.

Biotechnology and Food Science

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2014

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Vol. 78, nr 2

91--100

EN

Lavandulol and its esters play a significant role in the perfume and cosmetics industry. Because of their biological activity they have recently become relevant in research on pheromones. Many natural sources of this important alcohol are known along with synthetic methods allowing to achieve either an optically pure product or a racemic mixture. The article presents a short overview on new natural resources of the alcohol, its sensory and pheromonal characteristics and synthesis of its racemic mixture and enantiomers.

3

Substrate inhibition in lipase-catalysed transesterification of mandelic acid with vinyl acetate

Dąbkowska K., Pilarek M., Szewczyk K. W.

Chemical and Process Engineering

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2012

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Vol. 33, nr 4

539--546

EN

Kinetic resolution of (R)- and (S)-mandelic acid by its transesterification with vinyl acetate catalysed by Burholderia cepacia lipase has been studied. The influence of the initial substrate concentration on the kinetics of process has been investigated. A modified ping-pong bi-bi model of enzymatic transesterification of (S)-mandelic acid including substrate inhibition has been developed. The values of kinetic parameters of the model have been estimated. We have shown that the inhibition effect revealed over a certain threshold limit value of the initial concentration of substrate.

4

Chemia i technologia chiralna w środkach ochrony roślin

Połeć I., Komorowska-Kulik J., Legocki J.

Przemysł Chemiczny

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2007

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T. 86, nr 6

530-533

5

Zastosowanie ekstrakcji i technik membranowych do rozdziału stereoizomerów aminokwasów i ich pochodnych

Dżygiel P., Wieczorek P. P.

Wiadomości Chemiczne

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2004

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[Z] 58, 11-12

941--962

EN

Derivatives of amino acids are known from their great biological relevance, for example can be used as pharmaceuticals, crop protection substances or food additives. In significant number of cases such substances show their biological potency only as single enantiomer. Therefore, one of the most important conditions during their production is to ensure their high optical purity. Generally, two routes to accomplish this goal are considered to be most effective. The first one is to synthesize enantiomers with the support of chiral catalyst introduced into the reaction mixture. The second approach involves the preparation of racemic mixture and in final step to separate it into single enantiomers. Considering the separation the most popular methods are enantiomers crystallization in the form of diastereoisomeric salts and chromatographic separation of racemates with application of chiral stationary phases. However, despite of their very extensive use, those methods possess several drawbacks and limitations. Among them, the most inconvenient are large use of solvents and expensive, chiral substances acting as agents responsible for the enantioseparation. Additionally, in case of chromatography some problems with non-linearity of the chromatographic process can take place. Therefore, the study on alternative ways of achieving the efficient separation of enantiomers is carried out in many laboratories. In this review, the very promising methods of the stereoisomers separation namely extraction and membrane techniques are presented and discussed. In case of extraction the examples of classical liquid - liquid extraction as well as aqueous - aqueous extraction and solid phase extraction application for amino acids enantiomers and their derivatives separation are described. The special attention is paid on the use of membrane techniques. The brief overview of applications of different membrane processes for the same purpose including the use of chiral polymer membranes, molecularly imprinted membranes, achiral membranes with chiral agents (solution free or immobilized) and liquid membranes is also presented. Finally, the examples of preparative scale processes, in which extraction and membrane techniques were used, are also discussed to show their applicability for the production of amino acids and their derivatives with high amounts and optical purity.

6

Chiralność w związkach biologicznie czynnych ze szczególnym uwzględnieniem agrochemikaliów

Legocki J.

Prace Naukowe Instytutu Technologii Organicznej i Tworzyw Sztucznych Politechniki Wrocławskiej. Konferencje

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2002

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Vol. 51, nr 24

31-44

PL

W referacie przedstawiono znaczenie chiralności (izomerii optycznej) w związkach biologicznie czynnych, ze szczególnym uwzględnieniem agrochemikaliów (pestycydów). Omówiono zależność oddziaływania biologicznego od rodzaju enancjomeru.

EN

Chirality - one of the fundamental concepts in structural chemistry - belongs to the terms, which started to be commonly used in science from the beginning of 60-ties of the XXth century. The quickest progress on the area of chiral chemistry has been observed within the last few decades of XXth century, which was closely connected with research on the relationship between stereostructure and biological activity of many compounds. As practically each organism constitutes a chiral enviroment, the existence of a great deal of examples of enantiomeric selectivy seems to be fully justified. There is of big importance for pharmaceutical chemistry, but also still growing interest is notified on this area for the industry of plant protection agents, food flavours enhancers, syntetic fragrances, and many others. According to the data, concerning agrochemicals (pesticides) manufacturing, and published in 1996, market of chiral products in a global scale has attained the value of 9 billions, whereas the value of sales for those separated onto a single, pure enantiomers was higher than 2,6 billions USD. Knowledge of the fact that a desired activity, in general, is placed in only one of an enantiomeric pair, connected with technological and analytical possibilities, has led to legislative, ethical, ecological and commercial pressures to produce and apply only the active isomers. A difference between biological activity of indywidual enantiomers is particulary and clearly visible in the case of organophosphorous inhibitors of acetylcholinesterase.

7

Separation of four racemic benzodiazepines by HPLC

Goldnik A., Marszałek D., Paruszewski R.

Chemia Analityczna

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2002

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Vol. 47, No. 5

769-773

EN

A method for the separation and the determination of enantiomers of four benzodiazepines: oxazepam, lorazepam, temazepam and lormetazepam by HPLC on the Chiralcel OD-R (Diacel-Chemical Industries) column is presented. When the Chiralcel OD (Diacel-Chemical Industries) column was used, only the resolution of oxazepam and lormetazepam could be successfully performed.

PL

Przedstawiono metodę rozdzielania i oznaczania enancjomerów czterech benzodiazepin: oksazepamu, lorazepamu, temazepamu i lormetazepamu metodą HPLC na kolumnie Chiralcel OD-R (Diacel-Chemical Industries). Na kolumnie Chiralcel OD (Diacel-Chemical Industries) udało się rozdzielić jedynie oksazepam i lormetazepam.

8

Specific Interactions of Cu2+ Ions with Enantiomers of Hepatitis B Virus Surface Antigen 140-146 Region

Świątek-Kozłowska J., Brasuń J., Maćkiewicz Z., Kupryszewski G.

Polish Journal of Chemistry

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2001

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Vol. 75, nr 6

813-822

EN

Potentiometric and spectroscopic studies on Cu(II) interactions with 140-146 fragment of the hepatitis B virus antigen have shown that the basic binding sites of metal ion are centered at a peptide N-terminal donor system and the side chain donor atoms are not competing in the metal ion coordination.

9

Rationalization of enantioselective chromatography of 2-thioprominal by means of semiempirical AM1 calculations

Żuchowski G., Zborowski K., Bojarski J.

Chemia Analityczna

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2000

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Vol. 45, No. 6

767-779

EN

The inclusion complexes of p-cyclodextrin with neutral and anionic forms of enantio-mers of 5-ethyl-l-methyl-5-phenyl-2-thiobarbituric acid (2-thioprominal) have been modeled and energetically optimised by the application of AMI method. The resulting difference in minimised energies of complexes of enantiomeric forms of 5-ethyl-l-methyl-5-phenyl-2-thiobarbituric acid with p-cyclodextrin confirm the ability of p-cyclodextrin to act as a mobile phase additive in reversed-phase HPLC, to separate en-antiomers of 5-ethyl-l-methyl-5-phenyl-2-thiobarbituric acid during chromatography and rationalize their order of elution.

PL

Kompleksy inkluzyjne p-cyklodekstryny z obojętnymi i anionowymi formami enan-cjomerów kwasu 5-etylo-l-metylo-5-fenylo-2-tiobarbiturowego (2-tioprominalu) były modelowane przy zastosowaniu metody AM1. Wyznaczona za pomocą tej metody różnica zminimalizowanych energii kompleksów potwierdza przydatność P-cyklodekstryny, jako dodatku do fazy ruchomej w systemach z odwróconymi fazami HPLC, do rozdziału enancej omerów kwasu 5-etylo-l-metylo-5-fenylo-2-tiobarbiturowego podczas rozdziału chromatograficznego oraz tłumaczy porządek ich wymywania z kolumny.

10

Enantiomers of Hepatitis B Virus (HBV) Surface Antigen (140-146) S Region Fragment : Synthesis and Studies on Immunological Properties

Kunikowska D., Dera-Tomaszewska B., Dziadziuszko H., Wysocki J., Wolańska I., Maćkiewicz A., Głosnicka R., Kupryszewski G.

Polish Journal of Chemistry

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1999

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Vol. 73, nr 11

1803-1809

11

Alicja po drugiej stronie lustra

Wojciechowski P., Gancarz R.

Wiadomości Chemiczne

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1998

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[Z] 52, 9-10

699--711

EN

It is well known that living organisms show strong enantiometric selectivity on their molecular level. The enantiomorphic discrimination is sometimes manifested in the shape of an animal or plant. It was Pasteur who in 1857 discovered that the chemistry of life had a preferred handedness. 'Life is manifested to us as a function of the dyssymmetry of the universe' he wrote. Pasteur's work was carried out before the recognition of the quadrivalence of the carbon by Kekuléand Couper (1858). He did far more than simply discover the underlying theory of molecular asymmetry, he foresaw most of the consequences of that theory, he understood the principle of a transference of the asymmetric property from one set of molecules to another. Finally he clearly understood the biological implications of the discovery of asymmetry. The theory of organic stereochemistry has been established independently by Van't Hoff and Le Bell in 1874. Now, very frequently we have the question why there is no 'mirror life'. Would not biochemistry like ours with every configuration inverted be just as good? Was our way better or lucky? In 1957 it was found that mirror symmetry is broken on the subatomic level. Some elementary particles, like neutrino, exist only as left-handed objects. Thus, in fact, there are no exact enantiomers in our world. They are rather diastereoisomers of different energy. Thus, our mirror images friends living on the other side of the looking glass, with all the biological molecules with opposite configurations would not be as perfect as we are.