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1.

001-es BibID:BIBFORM106867
035-os BibID:(Wos)000825749700001 (Scopus)85133129093
Első szerző:Dékány-Adamoczky Anita (anyagmérnök)
Cím:Isocyanonaphthol Derivatives: Excited-State Proton Transfer and Solvatochromic Properties / Anita Adamoczky, Tibor Nagy, Péter Pál Fehér, Veronika Pardi-Tóth, Ákos Kuki, Lajos Nagy, Miklos Zsuga, Sándor Kéki
Dátum:2022
ISSN:1422-0067
Megjegyzések:Fluorescent probes that exhibit solvatochromic or excited-state proton-transfer (ESPT) prop- erties are essential tools for the study of complex biological or chemical systems. Herein, the synthesis and characterization of a novel fluorophore that reveals both features, 5-isocyanonaphthalene-1-ol (ICOL), are reported. Various solvatochromic methods, such as Lippert?Mataga and Bilot?Kawski, together with time-dependent density functional theory (TD-DFT) and time-resolved emission spec- troscopy (TRES), were applied to gain insights into its excited-state behavior. To make comparisons, the octyloxy derivative of ICOL, 5-isocyano-1-(octyloxy)naphthalene (ICON), was also prepared. We found that internal charge transfer (ICT) takes place between the isocyano and ?OH groups of ICOL, and we determined the values of the dipole moments for the ground and excited states of both ICOL and ICON. Furthermore, in the emission spectra of ICOL, a second band at higher wavelengths (green emission) in solvents of higher polarities (dual emission), in addition to the band present at lower wavelengths (blue emission), were observed. The extent of this dual emission increases in the order of 2-propanol < methanol < N,N-dimethylformamide (DMF) < dimethyl sulfoxide (DMSO). The presence of the dual fluorescence of ICOL in these solvents can be ascribed to ESPT. For ICOL, we also determined ground- and excited-state pKa values of 8.4 ? 0.3 and 0.9 ? 0.7, respectively, which indicates a considerable increase in acidity upon excitation. The TRES experiments showed that the excited-state lifetimes of the ICOL and ICON spanned from 10.1 ns to 5.0 ns and from 5.7 ns to 3.8 ns, respectively. In addition, we demonstrated that ICOL can be used as an effective indicator of not only the critical micelle concentration (cmc) of ionic (sodium lauryl sulfate (SLS)) and nonionic surfactants (Tween 80), but also other micellar parameters, such as partition coefficients, as well as to map the microenvironments in the cavities of biomacromolecules (e.g., BSA). It is also pointed out that fluorescence quenching by pyridine can effectively be utilized for the determination of the fractions of ICOL molecules that reside at the water?micelle interface and in the interior spaces of micelles.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:International Journal Of Molecular Sciences. - 23 : 13 (2022), p. 7250-7272. -
További szerzők:Nagy Tibor (1988-) (vegyész) Fehér Péter Pál (1991-) (vegyész) Pardi-Tóth Veronika Csilla Kuki Ákos (1966-) (villamosmérnök) Nagy Lajos (1979-) (vegyész) Zsuga Miklós (1944-) (polimer kémikus) Kéki Sándor (1964-) (polimer kémikus)
Pályázati támogatás:K-132685
OTKA
K-132236
OTKA
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Intézményi repozitóriumban (DEA) tárolt változat
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2.

001-es BibID:BIBFORM089662
035-os BibID:(cikkazonosító)5588 (scopus)85089170694 (wos)000558993700001
Első szerző:Dékány-Adamoczky Anita (anyagmérnök)
Cím:Conversion of Isocyanide to Amine in The Presence of Water and Hg(II) Ions: Kinetics and Mechanism as Detected by Fluorescence Spectroscopy and Mass Spectrometry / Anita Adamoczky, Lajos Nagy, Miklós Nagy, Miklós Zsuga, Sándor Kéki
Dátum:2020
ISSN:1661-6596 1422-0067
Megjegyzések:Aromatic isocyanides including isocyanonaphthalene derivatives have been proven to be very effective fluorescent sensors for the quantification of Hg(II) ions in water. Thus, the reaction of 1,5-isocyanoaminonaphthalene (1,5-ICAN), which is one of the most important members of this family, with water and HgCl2 as the oxidation agents, was studied by fluorescence spectroscopy and mass spectrometry in order to get deeper insight into the kinetics and mechanistic details of this complex reaction. The reactions of 1,5-ICAN with water and HgCl2 were performed in various water/co-solvent mixtures of different compositions. The co-solvents used in this study were both aprotic solvents including tetrahydrofuran, acetonitrile and N,N-dimethylformamide and protic solvents, such as ethanol and 2-propanol. It was found that in aprotic solvents the conversion of the isocyano group to amino moiety takes place, while in protic solvents the corresponding carbamate (urethane) group is formed in addition to the amino moiety. The variation of the resulting fluorescence intensities versus time curves were described using an irreversible, consecutive reaction model, in which the formation of isocyanate and carbamic acid intermediates, as well as diamino and carbamate (in the case of protic solvents) products were assumed. The formation of these intermediates and products was unambiguously confirmed by mass spectrometric measurements. Furthermore, by fitting the model to the experimental fluorescence versus time curves, the corresponding rate coefficients were determined. It was observed that the overall rate of transformation of the isocyano group to amino moiety increased with the water concentration and the polarity of the co-solvent. It was also supported that formation of diamino and carbamate derivatives in protic solvents takes place simultaneously and that the ratio of the amino to the carbamate function increased with the increasing water concentration. In addition, with an extension, the model presented herein proved to be capable of describing the kinetics of the transformation of 1,5-diisocyanonaphthalene (1,5-DIN) into 1,5-diaminonaphthalene (1,5-DAN) in the mixtures of water/aprotic solvents.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
steady-state fluorescence
kinetics
isocyanoaminonaphthalenes
HgCl2
carbamic acid
carbamate
isocyanate
Megjelenés:International Journal of Molecular Sciences. - 21 : 15 (2020), p. 1-14. -
További szerzők:Nagy Lajos (1979-) (vegyész) Nagy Miklós (1976-) (vegyész) Zsuga Miklós (1944-) (polimer kémikus) Kéki Sándor (1964-) (polimer kémikus)
Pályázati támogatás:NKFIH K-132685
egyéb
GINOP-2.3.2-15-2016-00041
GINOP
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Intézményi repozitóriumban (DEA) tárolt változat
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3.

001-es BibID:BIBFORM102834
035-os BibID:(WOS)000833649300001 (Scopus)85135127957
Első szerző:Kordován Marcell Árpád (okleveles vegyészmérnök)
Cím:Novel Polyurethane Scaffolds Containing Sucrose Crosslinker for Dental Application / Marcell Árpád Kordován, Csaba Hegedűs, Katalin Czifrák, Csilla Lakatos, Ibolya Kálmán-Szabó, Lajos Daróczi, Miklós Zsuga, Sándor Kéki
Dátum:2022
ISSN:1661-6596 1422-0067
Megjegyzések:: In this paper, the synthesis, characterization, and properties of crosslinked poly(?-caprolactone)- based polyurethanes as potential tissue replacement materials are reported. The polyurethane prepolymers were prepared from poly(?-caprolactone)diol (PCD), polyethylene glycol (PEG)/polylactic acid diol (PLAD), and 1,6-hexamethylene diisocyanate (HDI). In these segmented polyurethanes, the role of PEG/PLAD was to tune the hydrophobic/hydrophilic character of the resulting polymer while sucrose served as a crosslinking agent. PLAD was synthesized by the polycondensation reaction of D,L-lactic acid and investigated by matrix-assisted laser desorption/ionization time-offlight mass spectrometry (MALDI-TOF MS) and nuclear magnetic resonance spectroscopy (NMR). The crosslinked polyurethane samples (SUPURs) obtained were characterized by attenuated total reflectance Fourier-transform infrared spectroscopy (AT-FT-IR), swelling, and mechanical (uniaxial tensile tests) experiments. The thermo and thermomechanical behavior were studied by differential scanning calorimetry (DSC) and dynamical mechanical analysis (DMA). The viability of dental pulp stem cells was investigated in the case of polyurethanes composed of fully biocompatible elements. In our studies, none of our polymers showed toxicity to stem cells (DPSCs).
Tárgyszavak:Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
poly(e-caprolactone)
polyethylene glycol
polylactic acid diol
sucrose
mechanical testing
biological testing
Megjelenés:International Journal Of Molecular Sciences. - 23 : 14 (2022), p. 1-18. -
További szerzők:Hegedűs Csaba (1953-) (fogszakorvos) Czifrák Katalin (1978-) (vegyész) Lakatos Csilla (1990-) (környezetmérnök) Kálmán-Szabó Ibolya (1980-) (molekuláris biológus) Daróczi Lajos (1965-) (fizikus) Zsuga Miklós (1944-) (polimer kémikus) Kéki Sándor (1964-) (polimer kémikus)
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Intézményi repozitóriumban (DEA) tárolt változat
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4.

001-es BibID:BIBFORM100548
035-os BibID:(cikkazonosító)1444 (scopus)85123624843 (wos)000755083500001
Első szerző:Lakatos Csilla (környezetmérnök)
Cím:Synthesis of Sucrose-HDI Cooligomers : new Polyols for Novel Polyurethane Networks / Lakatos Csilla, Kordován Marcell Árpád, Czifrák Katalin, Nagy Lajos, Vadkerti Bence, Daróczi Lajos, Zsuga Miklós, Kéki Sándor
Dátum:2022
ISSN:1661-6596 1422-0067
Tárgyszavak:Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
sucrose
1,6-hexamethylene diisocyanate
cooligomer
polyol
Poly (E-caprolactone)
chemical and physical characterization
Megjelenés:International Journal Of Molecular Sciences. - 23 : 3 (2022), p. 1-13. -
További szerzők:Kordován Marcell Árpád (1994-) (okleveles vegyészmérnök) Czifrák Katalin (1978-) (vegyész) Nagy Lajos (1979-) (vegyész) Vadkerti Bence (1994-) (okleveles vegyészmérnök) Daróczi Lajos (1965-) (fizikus) Zsuga Miklós (1944-) (polimer kémikus) Kéki Sándor (1964-) (polimer kémikus)
Pályázati támogatás:GINOP-2.3.3-15-2016-00021
GINOP
FK-128783
Egyéb
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Intézményi repozitóriumban (DEA) tárolt változat
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5.

001-es BibID:BIBFORM098751
035-os BibID:(cikkazonosító)4059 (Scopus)85103999565 (Wos)000644301700001
Első szerző:Nagy Lajos (vegyész)
Cím:Kinetically Equivalent Functionality and Reactivity of Commonly Used Biocompatible Polyurethane Crosslinking Agents / Nagy Lajos, Vadkerti Bence, Lakatos Csilla, Fehér Péter Pál, Zsuga Miklós, Kéki Sándor
Dátum:2021
ISSN:1661-6596 1422-0067
Megjegyzések:In this paper, the kinetics of the reaction of phenyl isocyanate with crosslinking agents such as sucrose, sorbitol, and glycerol are reported. Crosslinking agents were used in high molar excess to isocyanate to obtain pseudo-first-order rate dependencies, and the reaction products were separated by high-performance liquid chromatography and detected by UV spectroscopy and mass spectrometry. It was found that the glycerol's primary hydroxyl groups were approximately four times reactive than the secondary ones. However, in the case of sorbitol, the two primary OH groups were found to be the most reactive, and the reactivity of hydroxyl groups decreased in the order of kOH(6)(8.43) > kOH(1)(6.91) > kOH(5)(1.19) > kOH(2)(0.98) > kOH(3)(0.93) > kOH(4)(0.64), where the numbers in the subscript and in the brackets denote the position of OH groups and the pseudo-first-order rate constants, respectively. The Atomic Polar Tenzor (APT) charges of OH groups and dipole moments of monosubstituted sorbitol derivatives calculated by density functional theory (DFT) also confirmed the experimental results. On the other hand, the reactions of phenyl isocyanate with crosslinking agents were also performed using high excess isocyanate in order to determine the number of OH-groups participating effectively in the crosslinking process. However, due to the huge number of derivatives likely formed in these latter reactions, a simplified reaction scheme was introduced to describe the resulting product versus reaction time distributions detected by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS). Based on the results, the kinetically equivalent functionality (fk) of each crosslinking agent was determined and found to be 2.26, 2.6, and 2.96 for glycerol, sorbitol, and sucrose, respectively.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
glycerol
sorbitol
sucrose
phenyl-isocyanate
reactivity
kinetics
Megjelenés:International Journal Of Molecular Sciences. - 22 : 8 (2021), p. 1-19. -
További szerzők:Vadkerti Bence (1994-) (okleveles vegyészmérnök) Lakatos Csilla (1990-) (környezetmérnök) Fehér Péter Pál (1991-) (vegyész) Zsuga Miklós (1944-) (polimer kémikus) Kéki Sándor (1964-) (polimer kémikus)
Pályázati támogatás:GINOP-2.3.3-15-2016-00021
GINOP
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Intézményi repozitóriumban (DEA) tárolt változat
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6.

001-es BibID:BIBFORM083939
035-os BibID:(cikkazonosító)1318 (scopus)85079681968 (wos)000522524400145
Első szerző:Nagy Lajos (vegyész)
Cím:Encoding Information into Polyethylene Glycol Using an Alcohol-Isocyanate "Click" Reaction / Nagy Lajos, Kuki Ákos, Nagy Tibor, Vadkerti Bence, Erdélyi Zoltán, Kárpáti Levente, Zsuga Miklós, Kéki Sándor
Dátum:2020
ISSN:1661-6596 1422-0067
Tárgyszavak:Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
monomethoxypolyethylene glycol (mpeg)
alipatic isocyanates
encoding and decoding binary information
maldi-tof ms
Megjelenés:International Journal Of Molecular Sciences. - 21 : 4 (2020), p. 1-9. -
További szerzők:Kuki Ákos (1966-) (villamosmérnök) Nagy Tibor (1988-) (vegyész) Vadkerti Bence (1994-) (okleveles vegyészmérnök) Erdélyi Zoltán (1974-) (fizikus) Kárpáti Levente (1968-) (okleveles vegyész) Zsuga Miklós (1944-) (polimer kémikus) Kéki Sándor (1964-) (polimer kémikus)
Pályázati támogatás:GINOP-2.3.3-15-2016-00021
GINOP
NKFIH-1150-6/2019
Egyéb
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Intézményi repozitóriumban (DEA) tárolt változat
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7.

001-es BibID:BIBFORM098735
035-os BibID:(cikkazonosító)864 (Scopus)85099577001 (Wos)000611325700001
Első szerző:Nagy Tibor (vegyész)
Cím:Mass Spectral Filtering by Mass-Remainder Analysis (MARA) at High Resolution and Its Application to Metabolite Profiling of Flavonoids / Nagy Tibor, Róth Gergő, Kuki Ákos, Zsuga Miklós, Kéki Sándor
Dátum:2021
ISSN:1661-6596 1422-0067
Megjegyzések:Flavonoids represent an important class of secondary metabolites because of their potential health benefits and functions in plants. We propose a novel method for the comprehensive flavonoid filtering and screening based on direct infusion mass spectrometry (DIMS) analysis. The recently invented data mining procedure, the multi-step mass-remainder analysis (M-MARA) technique is applied for the effective mass spectral filtering of the peak rich spectra of natural herb extracts. In addition, our flavonoid-filtering algorithm facilitates the determination of the elemental composition. M-MARA flavonoid-filtering uses simple mathematical and logical operations and thus, it can easily be implemented in a regular spreadsheet software. A huge benefit of our method is the high speed and the low demand for computing power and memory that enables the real time application even for tandem mass spectrometric analysis. Our novel method was applied for the electrospray ionization (ESI) DIMS spectra of various herb extract, and the filtered mass spectral data were subjected to chemometrics analysis using principal component analysis (PCA).
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
metabolomics
flavonoid
direct infusion mass spectrometry
mass spectral filtering
mass-remainder analysis
principal component analysis
Megjelenés:International Journal Of Molecular Sciences. - 22 : 2 (2021), p. 1-12. -
További szerzők:Róth Gergő (1994-) (vegyészmérnök) Kuki Ákos (1966-) (villamosmérnök) Zsuga Miklós (1944-) (polimer kémikus) Kéki Sándor (1964-) (polimer kémikus)
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Intézményi repozitóriumban (DEA) tárolt változat
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