Preparation and spectroscopic characterisation of metal complexes of piroxicam

Gehad, G.Mohamed; Nadia, E.A.El-Gamel

doi:10.1016/j.vibspec.2004.04.004

Cited by 38 publications

(18 citation statements)

References 33 publications

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“…Iron(II), cobalt(II), nickel(II) and zinc(II) almost certainly behave similarly to cadmium(II) [56,58,59]. A number of transition-metal complexes of piroxicam have been reported earlier [56][57][58][59][60][61][62], though by screening the literature, no studies concerning the synthesis, characterization and biological study of piroxicam complexes with transition metal ions, such as VO 2+ , MoO 2þ 2 , Mn 2+ , UO 2þ 2 and Fe 3+ are reported.…”

Section: Introductionmentioning

confidence: 89%

“…This shift can be assigned to the donation of the lone pair of the pyridyl nitrogen atom of Hpir to the metal ion (N ! M) [62]. The changes in the UV spectra of the complexes in comparison with that of piroxicam may be attributed to the donation of the lone pair of electrons of O amide and N pyr atoms to the metal ions centers (O !…”

Section: Electronic Spectroscopy Of the Complexesmentioning

confidence: 99%

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Mononuclear metal complexes with Piroxicam: Synthesis, structure and biological activity

Christofis

Katsarou

Papakyriakou

et al. 2005

Journal of Inorganic Biochemistry

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Section: Introductionmentioning

confidence: 89%

Section: Electronic Spectroscopy Of the Complexesmentioning

confidence: 99%

Mononuclear metal complexes with Piroxicam: Synthesis, structure and biological activity

Christofis

Katsarou

Papakyriakou

et al. 2005

Journal of Inorganic Biochemistry

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“…Equation (21) presents two terms, the first term can be neglected if the equilibrium constant of the complex, K eq , is higher than 1 × 10 2 . However, a higher value of K eq for the complex was previously reported [52,53].…”

Section: Resultsmentioning

confidence: 63%

“…We also explored the applicability of equations (19) and (20) to the Cu(II)-Piroxicam system. On the basis of previous studies on the Cu(II)-Piroxicam complex in solution [50,52,53] and on Cu(II)-Piroxicam crystal structure (Figure 3, [49]), we assumed the prevalence of the Cu(II)(Pix) 2 complex in solution.…”

Section: Resultsmentioning

confidence: 99%

Metal-Ligand Recognition Index Determination by NMR Proton Relaxation Study

et al. 2019

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In this study, we developed and validated a new proposed parameter quantifying the interaction strength between natural and/or synthetic molecules with paramagnetic metal ions. The Metal ion Recognition Index, Miri, is a quantitative parameter to describe the proton environment and to define their involvement in the inner and/or outer sphere of the paramagnetic metal ion. The method is based on the analysis of NMR proton spin-lattice relaxation rates of a specific ligand in both the diamagnetic and paramagnetic conditions. The proposed procedure is also useful to calculate the ligand proton spin-lattice relaxation rate in the paramagnetic bound conditions, which is typically very difficult to determine experimentally. Miri was used to compare the ligand proton involvement toward different paramagnetic species, in particular the Copper(II)-Piroxicam system. Copper(II)-Piroxicam complex is one of the most active anti-inflammatory and anti-arthritic species. Miri provides an opportunity to improve our knowledge of metal-ligand complexes that play a fundamental role in bioinorganic interactions.

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“…X-ray crystallographic and Fourier transform infrared studies of CuPRX showed that the C═O of the amide group and N atom of the pyridyl group of the PRX ligand coordinate with the Cu ion, as shown in Scheme 1. 5,[21][22][23] It is generally known that the ESIPT results in a proton transfer from the O H group of the benzothiazine ring to the C═O of the amide group in the EZE conformer of PRX (Scheme 1a). 24,25 However, no information concerning the ESIPT process has been reported for ZZZ-PRX.…”

Section: Steady-state Absorption and Emission Spectral Propertiesmentioning

confidence: 99%

Photophysical properties of anti‐inflammatory piroxicam and its Cu(II) complex

Choi

Ahn

Wee

et al. 2021

Bulletin Korean Chem Soc

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Piroxicam (PRX), a nonsteroidal anti-inflammatory drug, exhibits a large Stokesshift emission owing to the excited-state intramolecular proton transfer (ESIPT) from enol-PRX to keto-PRX. In contrast, the Cu-coordinated PRX complex (CuPRX) does not show any emission at 300 K. In the time-resolved transient absorption (TA) spectra, PRX showed two positive TA bands at 430 and 700 nm, corresponding to the S 1 -S n transitions of keto-PRX * and a negative bleaching band at 540 nm due to ESIPT emission. These TA bands decayed with a lifetime of approximately 50 ps. CuPRX showed similar TA features, but no bleaching band was observed for CuPRX and decayed rapidly within 3 ps, indicating a rapid intersystem crossing process owing to the heavy atom effect. Based on the experimental results and theoretical calculations, the fate for excited keto-PRX is discussed in terms of the ESIPT and reverse ESIPT processes.

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Preparation and spectroscopic characterisation of metal complexes of piroxicam

Cited by 38 publications

References 33 publications

Mononuclear metal complexes with Piroxicam: Synthesis, structure and biological activity

Mononuclear metal complexes with Piroxicam: Synthesis, structure and biological activity

Metal-Ligand Recognition Index Determination by NMR Proton Relaxation Study

Photophysical properties of anti‐inflammatory piroxicam and its Cu(II) complex

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