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International Conference on Molecular Spectroscopy, Białka Tatrzańska 2017
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T6: P–9
Synthesis and spectroscopic properties of γ,δ-unsaturated lactones
Angelika Kamizela
1
, and Barbara Gawdzik
1
1
Institute of Chemistry, Jan Kochanowski University in Kielce, Świętokrzyska st. 15 G, 25-406 Kielce,
Poland, e-mail: angelikakamizela@o2.pl
Lactone compounds are of great interest of many research groups due to their sensory
properties [1] and the wide range of biological activities. They possess antimicrobial, antiviral,
anti-inflammatory and anti-cancer activities [2]. Since ancient times, plant extracts containing
lactones have been used as medicinal substances to treat many diseases in folk medicine.
Currently, many of them are active compounds in proven drugs. Lactones have been used in the
pharmaceutical industry as active ingredients in medicines, as well as in the cosmetic and food
industries, as flavors [1, 2]. Literary data gives the information about synthetic and
biotechnological [3] methods for the synthesis of these cyclic esters.
Continuing our research on synthesis of this group of compounds, we present a new five-
step synthetic pathway for γ,δ-unsaturated lactones. The first step was the Grignard reaction of
α-naphthylmagnesium bromide with trans-crotonaldehyde or 3-methylcrotonaldehyde.
Secondary allyl alcohols obtained were subjected to [3] – sigmatropic rearrangement affording
corresponding δ-unsaturated ethyl esters. Their subsequent hydrolysis with ethanolic KOH
solution yielded corresponding carboxylic acids. The fourth step in the lactone synthesis was the
iodolactonization carried out in the presence of I2 in KI. The final step was a dehalogenation
reaction with DBU
The structures of all of γ,δ-unsaturated lactones products have been confirmed by IR and
NMR spectral spectroscopy. In addition, X-ray analysis was performed for crystalline lactones.
Keywords: lactone; halolactone; cyclic esters; unsaturated lactones
References
[1] B.
Gawdzik, A. Kamizela, A. Szyszkowska, Chemik 69 (2015) 342.
[2] K. Libiszewska, Biotechnol Food Sci. 75 (2011) 45.
[3] J. Krzaczkowska, E. Białecka-Florjańczyk, I. Stolarzewicz 2009, Biotechnological methods
of odor preparation
, Food. Science. Technology. Quality, 3, 64, pp. 5–18.
XIV
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International Conference on Molecular Spectroscopy, Białka Tatrzańska 2017
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T6: P–10
SERS and DFT investigations of 99mTc-labeled radiopharmaceuticals
Krzysztof Żamojć
1
, Magdalena Zdrowowicz
1
,
Paweł Błażej Rudnicki-Velasquez
1
, and Lech Chmurzyński
1
1
Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, 80-308 Gdansk, Poland,
e-mail: krzysztof.zamojc@ug.edu.pl
TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) and its derivatives are stable membrane
permeable nitroxide radicals, which effectively protect cells and tissues from damages due to the
presence of oxidative and nitrosative stress conditions. Profluorescent nitroxides have been
reported previously as probes for a detection of free radicals as well as damages mediated by
these species [1, 2]. On the other hand there is no literature data on fluorescent sensors (which
display the fluorescence enhancement) used for the detection of nitroxides. We report herein
dihydroxycoumarins as highly selective fluorescent probes for the fast detection of TEMPO and
its derivatives.
A series of chosen dihydroxy-substituted coumarin derivatives has been studied with the use
of different analytical techniques as fluorescent sensors for TEMPO radical and its derivatives.
The UV absorption and fluorescence emission spectra of these coumarins were recorded in
aqueous solutions at the room temperature in the absence and presence of the increasing
amounts of TEMPO and its derivatives (4-amino-TEMPO, 4-acetamido-TEMPO,
4-oxo-TEMPO, 4-hydroxy-TEMPO, 4-methoxy-TEMPO). In the case of strictly physical
interactions – the fluorescence quenching – the mechanism of the quenching and Stern-Volmer
quenching constants were determined. In the case of some coumarins, the fluorescence intensity
under the action of the TEMPO radical (namely 4-amino-TEMPO) increased significantly. We
have stated that the unique fluorescence enhancement attributes to the formation of each
coumarin dimer (Figure below). The products were determined with the use of HPLC coupled
with mass spectrometry as well as NMR spectroscopy. Additionally, limits of the detection
(LOD) and quantitation (LOQ) of appropriate nitroxides with the use of dihydroxycoumarins
were determined.
Keywords: dihydroxy-substituted coumarins; TEMPO derivatives; fluorescence spectroscopy
Acknowledgment
This work was supported by the National Science Centre (Poland) under the Grant No.
2016/23/D/ST4/01576.
References
[1] Blinco J.P., Keddie D.J., Wade T., Barker P.J., George G.A., Bottle S.E., Polym. Degrad. Stab. 93
(2008) 1613.
[2] Aspée A., Maretti L., Scaiano J.C., Photochem. Photobiol. Sci. 2 (2003) 1125.
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