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Nowe formy lizozymu możliwości produkcji i wykorzystania

Leśnierowski G., Cegielska-Radziejewska R.

Przemysł Spożywczy

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2016

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T. 70, nr 4

27--29

PL

Lizozym to białko enzymatyczne, powszechnie występujące w przyrodzie, charakteryzujące się wieloma użytecznymi właściwościami, które umożliwiają wszechstronne jego wykorzystanie. Obecnie praktyczne zastosowanie enzymu dotyczy monomeru, a już wkrótce zapewne także jego zmodyfikowanej postaci. W porównaniu z monomerem zmodyfikowany lizozym wykazuje bowiem zdecydowanie większe możliwości przeciwdrobnoustrojowego działania. Dzieje się tak dzięki pojawieniu się w nim nowej, specyficznej, antybakteryjnej aktywności wobec drobnoustrojów Gram-ujemnych. Wykazuje wiele nowych właściwości, istotnych z punktu widzenia medycznego, farmaceutycznego i weterynaryjnego. Można się zatem spodziewać, że zmodyfikowany enzym będzie praktycznie wykorzystywany nie tylko w przemyśle spożywczym, ale także w medycynie, weterynarii i farmakologii. Obecnie prowadzone badania pozwoliły na opracowanie oryginalnych sposobów modyfikacji lizozymu, umożliwiających wytworzenie produktu wysokiej jakości. Niektóre z tych metod, np. metodę termiczną, termiczno-chemiczną, chemiczną czy membranową, w prosty sposób można przenieść z warunków laboratoryjnych do skali półtechnicznej czy nawet przemysłowej.

EN

Lysozyme is an enzyme protein, commonly found in nature, characterized by many useful properties that allow its versatile use. The current practical application of the enzyme concerns monomer, and soon, also its modified forms. Wider use should be linked just with the possibility of using the modified enzyme and not only in the food industry but also in medicine, veterinary medicine and pharmacology. Current research allowed developing original methods to modify lysozyme, enabling manufacture of a high quality product. Some of them, like thermal, thermalwidzenia -chemical, and chemical or membrane method are easy to be transferred from the laboratory conditions to the pilot or even industrial scale. The aim of this study was to present the methods of obtaining and modifying lysozyme causing its oligomerization, the methods of assessment of physicochemical properties of the modified lysozyme and its antibacterial action and the possibility of its practical application.

2

Crystal Structure, Infrared Spectra and Density Functional Theory Study on 2,3-Diketo-benzopiperazine Dimer

Zhao P., Jian F. F., Xiao H., Sun P.

Polish Journal of Chemistry

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2004

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Vol. 78 / nr 10

1935-1944

EN

2,3-Diketo-benzopiperazine, which exists as dimeric form in its crystal structure has been synthesized. The calculated results on the dimer at B3LYP/6-31G* level show that the average strength of the double hydrogen bonds is of medium-grade. Natural bond orbital analyses have been performed. The predicted harmonic vibration frequencies support the experimental values. The thermodynamic properties of the dimer at different temperatures have been calculated and the change of Gibbs free energy for the aggregation from the monomer to the dimerDelta GT = -30.86 kJ/mol at 298.15 K, which implies the spontaneous process of the dimer formation.

3

Density functional studies of the cobaltous acid dimer : preliminary results

Gajewski G., Latajka Z., Ratajczak H.

Bulletin of the Polish Academy of Sciences. Chemistry

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2002

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Vol. 50, No. 2

131-137

EN

The structure, interaction energy and vibrational frequencies of the hydrogen bonded cobaltous acid monomer and dimer were investigated at the B3LYP level with the CEP-31G** basis set. The cobaltous acid forms stable cyclic dimer with the dimerization energy of about -14 kcal/mol. The structural parameters of monomers are strongly perturbed upon dimerization, and the vibrational spectra are predicted to show large vibrational shifts compared with the monomer spectra.

4

Conformational analysis of 1,2,4,5-tetroxane

Jorge N., Gomez-Vara M., Romero J. R., Castro E. A.

Bulletin of the Polish Academy of Sciences. Chemistry

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2002

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Vol. 50, No. 3

387-395

EN

Different theoretical procedures are applied to make a conformational study of the 1,2,4,5-tetroxane molecule: AMI semi-empirical method, ab initio RHF method at the 3-21+G and 6-311+G(d,p) basis set levels and B3LYP density functional method at the same basis set levels. The molecular stability is analyzed on the basis of different stereo-electronic and symmetry features. There is a general agreement between these methods and all of them predict the chair conformation to be the most stable conformer.

5

Synteza dimerów i estolidów nienasyconych kwasów tłuszczowych oraz ich adduktów z bezwodnikiem maleinowym

Wasilewicz-Niedbalska W., Chmielarz B., Kosmacińska B., Dyczewski M., Wiślicki B., Zdrodowska B.

Przemysł Chemiczny

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2001

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T. 80, nr 2

52-55

6

Mechanizm i kinetyka procesów tworzenia oraz zaniku ekscymerów XeCl* w układach Xe-RCl

Wojciechowski K.

Wiadomości Chemiczne

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1998

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[Z] 52, 5-6

405-429

EN

The mechanism and kinetics of decay of excited Xe(6s[3/2]1,2) atoms formed by irradiation of pure Xe by xenon resonance light (l = 147 nm) is presented basing on Moutard et al. [9] reaction scheme (r.(2)-(8)). The mechanism of the decay of higher xenon excited states (6p, 6d, ...) produced by the electron beam is also presented (r.(9)-(14)). On this basis the mechanism and kinetics of energy transfer processes to RCl molecules in Xe-RCl system leading to XeCl(B,C) excimers is discussed. In particular the mechanism and kinetics of two-and three-body reactions of the lowest Xe(6s[3/2]1) state with chlorine donor molecules is presented. It has been shown that the two-body energy transfer reactions (19) occur with the rate constants in the range (3.5-7)ˇ10-10 cm3 ˇs-1 [10, 11, 32, 33] (Tabs.1,2). The yield of XeCl* excimers in these reactions is in the range from 0.02 for HCl up to 1.0 for Cl2 molecule (Tabs 1,2). It has been shown also that at higher xenon pressures (above 20-50 Torr) with reaction (19) competes the fast three-body reaction (23), which also is a source of XeCl* excimers [10, 11]. The rate constants of reaction (23) for a few molecules are shown in Tab. 2. They are in the range (1-2)ˇ10-28 cm6 ˇs-1 and the yields of XeCl* excimers produced in these reactions are from 0.19 for CCl4 up to 0.5 for PCl3. It seems to be important in the construction of excimer lasers that in the case of HCl molecule, often used as a source of XeCl* excimers, the rate constant of three-body energy transfer reaction (23) is extremely high, k23 = 2.2ˇ10-27 cm6ˇs-1 [10] and the yield of XeCl* excimersin this process is equal to zero [10]. The XeCl* excimers decay via fluorescence with the maximum at l =308 nm, for B-X transition and l = 340 nm for C-A transition. The typical spectrum of XeCl* excimers fluorescence is shown in Fig. 5. The fluorescence lifetime (r. (31), (32)) of XeCl* excimers is equal to 11 and 120-130 ns, for B-X and C-A transitions, respectively [46, 58]. There is shown that the above values of XeCl* excimers lifetimes concern excimers at the lowest vibrational level (v = 0) and they increase with v number (see Fig. 7)[43]. The mechanism and kinetics of collisional decay of highly vibrational XeCl(B,C) excimers with buffer gases (He, Ne, Ar, Kr) is also presented (r.(27)-(30)) [43]. The relaxed XeCl(B,C) excimers decay also in the two-and three-body quenching with Xe and RCl molecules. The mechanism and kinetics of above processes is shown (see reaction (35)-(37) and Tab. 4).

7

Isoelectronic dimers [(XH3)2, (YH2)2, (ZH)2, and (Rg)2] in the groups of the periodic system: ab initio quantum chemical calculations

Hobza P., Burda J.V., Zahradnik R.

Polish Journal of Chemistry

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1998

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Vol. 72, nr 7S

1497-1504

EN

The (ZH)2, (YH2)2, (XH3)2 and (Rg)2 dimers [Z=F-At; Y=O.Po; X=N, Bi; Rg=rare gas] were studied ab initio using the CCSD(T) and MP2 procedures. Average relativistic effective potentials were used for all the halogens, while Stuttgart effective core potentials were used for the remaining non-hydrogen atoms. All the (HX)2 structure are H-bonded. All the stabilization energies mutually approach when passing down the group of the periodic system.