Wyniki wyszukiwania

1

Esters of 2,4-dichlorophenoxy- and 4-chloro-2-methylphenoxyacetic acids - synthesis and infrared spectroscopy. Part II. sec-Alkyl esters

100%

Zelechowski K., Kielczewska A., Legocki J.

Pestycydy

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2005

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nr 3

7-20

2

Chirality and the nature of food authenticity of aroma

100%

Zawirska-Wojtasiak R.

Acta Scientiarum Polonorum. Technologia Alimentaria

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2006

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tom 05

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nr 1

The phenomenon of chirality, common in nature, pertains also to food components. The effect of the chiral structure of chemical compounds is the occurrence of optical isomers, i.e. enantiomers. The only source of optically active substances are living organisms, which produce most frequently mostly one of isomers. Proteins and carbohydrates are chiral: amino acids are found in proteins only in the L form, whereas carbohydrates are formed of D-saccharides. Enantiomers may exhibit diverse behaviour in reactions with biologically active compounds of living organisms. Chiral structure of proteins turned out to be significant in the perception of taste perceptions as well as the perception of aroma. The most characteristic phenomenon is chirality among odorants. Numerous compounds essential for aroma are found in nature in the form of two isomers, with considerable predominance of one of them, while the ratio of these isomers is specific and stable. Enantiomers of odorants may differ in the intensity and character of their smell. The phenomenon of chirality has been known since mid-1800; however, it then constituted a serious analytical problem. Only the development of methods facilitating the separation of optical isomers created a possibility to investigate its universality and importance in living organisms. The application of more and more advanced analytical techniques in the control of chiral nature of food ingredients may be used to detect adulterations and especially to determine authenticity of fragrances.

3

Enantiomers of 2-butyl esters of 2,4-dichlorophenoxy- and 4-chloro-2-methylphenoxyacetic acids

84%

Zelechowski K., Krawczyk M., Legocki J.

Pestycydy

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2006

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nr 3-4

9-16

4

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Chiral changes of cortical microtubule orientations in epidermis of sunflower hypocotyls. The effect of blue and red light

84%

Burian A.

Acta Societatis Botanicorum Poloniae

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2007

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tom 76

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nr 4

269-275

Light and developmental processes affect the cortical microtubule (cMT) orientation. The cMT orientation with a special regard to its chirality was analyzed under the outer epidermal cell walls in different regions of sunflower hypocotyls kept in darkness and after irradiation with blue and red light. The results show that the cMT orientation depends on the cell position along hypocotyl, but generally cMTs are oblique. The oblique orientation has defined chirality: either of Z-form (right-handed) or S-form (left-handed). In the lower region of hypocotyls the Z-form dominates. After irradiation of hypocotyls with blue light this domination has been maintained and appeared also in the upper region. In contrast, after irradiation with red light the Z-form domination has not been apparent. It is proposed that in darkness, variations of cMT orientations in the epidermis along the hypocotyl are due to developmental processes, while blue and red light affect the cMT orientation via "shifting" these processes backward and forward, respectively.

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Chromatograficzny rozdzial enancjomerow w analizie zywnosci i produktow naturalnych

67%

Bojarski J.

Żywność Nauka Technologia Jakość

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2000

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tom 07

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nr 2

120-127

W artykule podano podstawowe definicje chiralności oraz metodykę chromatograficznego rozdziału oznaczania enancjomerów w produktach żywnościowych i naturalnych. Zaprezentowano także odpowiednie przykłady oznaczania antypodów optycznych aminokwasów oraz związków zapachowych smakowych, zaczerpnięte z literatury.

6

From research on the use of chiral ionic liquids with a natural origin substituent for wood protection

67%

Zabielska-Matejuk J., Feder-Kubis J., Stangierska A.

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2014

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tom 88

From research on the use of chiral ionic liquids with a natural origin substituenl for wood proteclion. Antifungal activities of chiral ionic liquids - menthoxymethylimidazolium derivates against brown-rot decay fungus (Coniophora puteana), white-rot decay fungus (Trametes versicolor) and blue-stain fungus (Sclerophoma pithyophila) were determined using screening agar-plate and agar-block methods. Results from antifungal tests revealed that 1-hexyl-3-[(1R,2S,5R)-(-)menthoxymethyl]imidazolium chloride exhibited the strongest antifungal activity against wood decay fungi (basidiomycetes) compared with the commercial didecyldimethylammonium chloride. Whereas compound with twelve carbons alkyl substituent has a weak antifungal activity. The infrared spectral analysis (FTIR ATR) confirmed that chiral imidazolium ionic liquids were built into the structure of the treated wood.

Ograniczanie wyników

2 Pestycydy

1 Acta Scientiarum Polonorum. Technologia Alimentaria

1 Acta Societatis Botanicorum Poloniae

1 Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

1 Żywność Nauka Technologia Jakość

2 Legocki J.

2 Zelechowski K.

1 Bojarski J.

1 Burian A.

1 Feder-Kubis J.

1 Kielczewska A.

1 Krawczyk M.

1 Stangierska A.

1 Zabielska-Matejuk J.

1 Zawirska-Wojtasiak R.

1 2014

1 2007

2 2006