Novel Co(II) and Cd(II) complexes with non-steroidal anti-inflammatory drugs

Kafarska, Karolina; Czakis-Sulikowska, D.; Wolf, Wojciech M.

doi:10.1007/s10973-008-9456-6

Cited by 18 publications

(16 citation statements)

References 14 publications

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“…Our studies were stimulated by the fact that majority of anti-inflammatory drugs are carboxylic acids with their carboxylate group prone to metal binding [11,[18][19][20]. Some of mefenamate complexes have been described in the literature.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Spectroscopic, and Thermal Investigations of Metal Complexes with Mefenamic Acid

Kafarska

Gacki

Wolf

2017

Journal of Chemistry

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The novel metal complexes with empirical formulae M(mef) 2 ⋅nH 2 O (where M = Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II); mef is the mefenamic ligand) were synthesized and characterized by elemental analysis, molar conductance, FTIR-spectroscopy, and thermal decomposition techniques. All IR spectra revealed absorption bands related to the asymmetric (] as ) and symmetric (] s ) vibrations of carboxylate group. The Nakamoto criteria clearly indicate that this group is bonded in a bidentate chelate mode. The thermal behavior of complexes was studied by TGA methods under non-isothermal condition in air. Upon heating, all compounds decompose progressively to metal oxides, which are the final products of pyrolysis. Cu(II), Zn(II), and Cd(II) complexes were also characterized by the coupled TG-FTIR technique, which finally proved the path and gaseous products of thermal decomposition. Additionally, the coupled TG-MS system was used to determine the principal volatile products of thermolysis and fragmentation processes of Mn(mef) 2 ⋅3H 2 O and Co(mef) 2 ⋅2H 2 O.

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Section: Introductionmentioning

confidence: 99%

Synthesis, Spectroscopic, and Thermal Investigations of Metal Complexes with Mefenamic Acid

Kafarska

Gacki

Wolf

2017

Journal of Chemistry

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“…QPEPIN6: Produto formado a partir da reação entre quitosana-epicloridrina e naproxeno sob as condições: razão molar QP-NAP/ 1,00:1,50; 48 hs; 40°C; RMN de 13 C: Espectroscopia de Ressonância Magnética Nuclear de 13 Sendo proveniente da família do ácido propanoico, este apresenta uma estrutura composta por uma porção alifática, estrutura do ácido propanoico e uma porção aromática, que remete à estrutura do naftaleno. Além disso, nessa família destacam-se os fármacos ibuprofeno, cetoprofeno, fenoprofeno, butibufeno, flurbiprofeno, dentre outros.…”

Section: Tabelaunclassified

“…Este produto de reação foi chamado de QN1. Neste caso, quando calculado o grau de substituição (GS) por meio da técnica de RMN de 13 C, observou-se um GS de 19,1 %, sugerindo uma neutralização do grupo NH2 ligado ao C2 do biopolímero com o grupo COOH presente no fármaco. Nos espectros de FTIR foram observadas bandas que correspondem a formação de um produto diferente de QP e NAP, corroborando com a hipótese de formação do sal QN1.…”

Section: Introductionunclassified

“…No entanto, a reação teve um menor rendimento quando comparada com o sal não reticulado. Verificou-se pelas diferentes técnicas de caracterização, sobretudo, por RMN de 13 C que, ao invés de organizar e deixar os grupos amino ainda mais suscetíveis à reação, a estrutura da quitosana organizou-se de forma que houve menos interação com o fármaco. Portanto, para os sais QN1 e QPEPIN1 foi realizado o estudo do equilíbrio de dissociação por HPLC, em pH 2,00 e 7,00, simulando condições do intestino e estômago, afim de verificar o seu perfil de dissociação e comportamento nessas soluções.…”

Section: Introductionunclassified

“…Ao Prof. Dr. Tiago Venâncio da UFSCar pelas contribuições nas medidas de RMN de 13 Acreditar na capacitação pessoal é um exercício que requer muita paciência e perseverança. Crescer em uma sociedade que impõe padrões sociais sobre as pessoas não é fácil, visto que as oportunidades não são iguais para toda população.…”

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Preparação, caracterização e estudo de dissociação do naproxeno em uma matriz de quitosana

Medeiros¹

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Studies were carried out to optimize the reaction conditions to obtain a naproxen (NAP) salt (QN) and the chitosan biopolymer (QP). This salt (QN) was used for the study of antiinflammatory dissociation equilibrium. For this, the best conditions were studied in relation to the parameters reaction time, reaction temperature and molar ratio of the reactants. The products were characterized by nuclear magnetic resonance NMR of hydrogen 1 H and carbon 13 C, Fourier transform infrared vibration spectroscopy, FTIR, ultraviolet-visible electronic spectroscopy in the diffuse reflectance, UV-vis, diffraction (XRD) and thermoanalytical techniques: thermogravimetry and differential thermal analysis simultaneous (TG/DTA) and differential scanning calorimetry (DSC). In addition, the evolution of gases by thermogravimetry coupled to spectrometer FTIR (TG-FTIR) was studied. It was found that the higher salt yield was obtained under the following reaction conditions: 24 hours, temperature of 60 ° C and molar ratio of 1 mol of QP to 1.05 mol of NAP. This reaction product was called QN1. In this case, when calculating the degree of substitution (GS) by the 13 C NMR technique, a GS of 19.1% was observed, suggesting a neutralization of the NH2 group bound to the C2 of the biopolymer with the COOH group present in the drug. In the FTIR spectra were observed bands corresponding to the formation of a product different than QP and NAP, corroborating with the hypothesis of QN1 salt formation. In the UV-vis spectrum the three bands were observed for the absorption of the chromophore groups present in the salt. In the diffractograms, there was a peak in the region of ~22θ in QN1, which was already observed as a shoulder in QP, but there was an increase, in addition, changes in the index of crystallinity of chitosan, suggested modifications in its semicrystalline structure after reaction with the NAP. The TG / DTG / DTA curves showed changes in the thermal behavior of QN1 in relation to QP, showing that the modification leads to changes in the thermal behavior and suggest the presence of NAP in the biopolymer matrix. The characterization confirmed the hypothesis of salt formation, QN1, because there were modifications in the intervals of mass loss, as well as, by the ratio between the third and second loss of mass, a stability gain can be verified. In order to improve the NAP-QP interaction capacity, the chitosan chains were crosslinked with epichlorohydrin. However, the reaction had a lower yield when compared to the uncrosslinked salt. It was verified by the different characterization techniques, mainly by 13 C NMR that, instead of organizing and leaving the amino groups even more susceptible to reaction, the chitosan structure was organized in a way that there was less interaction with the drug. Therefore, for the salts QN1 and QPEPIN1 the study of the equilibrium of dissociation by HPLC, at pH 2,00 and 7,00, was carried out, simulating conditions of the intestine and stomach, in order to verify their profile of dissociation and behavior...

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