7 research outputs found
Spectroscopic studies on photoinduced reactions of the anticancer prodrug, trans,trans,trans-[Pt(N3)2(OH)2(py)2]
The photodecomposition mechanism of trans,trans,trans-[Pt(N3)2(OH)2(py)2] (1, py = pyridine), an anticancer prodrug candidate, was probed using complementary Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR), transient electronic absorption and UV-Vis spectroscopy. Data fitting using Principal Component Analysis (PCA) and multi-curve resolution alternating least squares, suggests the formation of a trans-[Pt(N3)(py)2(OH/H2O)] intermediate and trans [Pt(py)2(OH/H2O)2] as the final product upon 420 nm irradiation of 1 in water. Rapid disappearance of the hydroxido ligand stretching vibration upon irradiation is correlated with a -10 cm-1 shift to the anti-symmetric azido vibration, suggesting a possible second intermediate. Experimental proof of subsequent dissociation of azido ligands from platinum is presented, where at least one hydroxyl radical is formed in the reduction of Pt(IV) to Pt(II). Additionally, the photoinduced reaction of 1 with 5'-guanosine monophosphate was studied, and the identity of key photoproducts was assigned with the help of ATR FTIR spectroscopy, mass spectrometry and DFT calculations. The identification of marker bands for photoproducts, e.g. trans-[Pt(N3)(py)2(5'-GMP)] and trans-[Pt(py)2(5'-GMP)2], will aid elucidation of the chemical and biological mechanism of anticancer action of 1. In general, these studies demonstrate the potential of vibrational spectroscopic techniques as promising tools for studying such metal complexes
Comprehensive vibrational spectroscopic investigation of trans,trans,trans-[Pt(N3)2(OH)2(py)2], a Pt(IV) diazido anticancer prodrug candidate
We report a detailed study of a promising photoactivatable metal-based anticancer prodrug candidate, trans,trans,trans-[Pt(N3)2(OH)2(py)2] (C1; py = pyridine), using vibrational spectroscopic techniques. Attenuated total reflection Fourier transform infrared (ATR-FTIR), Raman, and synchrotron radiation far-IR (SR-FIR) spectroscopies were applied to obtain highly resolved ligand and Pt-ligand vibrations for C1 and its precursors (trans-[Pt(N3)2(py)2] (C2) and trans-[PtCl2(py)2] (C3)). Distinct IR- and Raman-active vibrational modes were assigned with the aid of density functional theory calculations, and trends in the frequency shifts as a function of changing Pt coordination environment were determined and detailed for the first time. The data provide the ligand and Pt-ligand (azide, hydroxide, pyridine) vibrational signatures for C1 in the mid- and far-IR region, which will provide a basis for the better understanding of the interaction of C1 with biomolecules
Studies of Carbon Monoxide Release from Ruthenium(II) Bipyridine Carbonyl Complexes upon UV-Light Exposure
The
UV-light-induced CO release characteristics of a series of rutheniumÂ(II)
carbonyl complexes of the form <i>trans</i>-ClÂ[RuLCl<sub>2</sub>(CO)<sub>2</sub>] (L = 4,4′-dimethyl-2,2′-bipyridine,
4′-methyl-2,2′-bipyridine-4-carboxylic acid, or 2,2′-bipyridine-4,4′-dicarboxylic
acid) have been elucidated using a combination of UV–vis absorbance
and Fourier transform infrared spectroscopies, multivariate curve
resolution alternating least-squares analysis, and density functional
theory calculations. In acetonitrile, photolysis appears to proceed
via a serial three-step mechanism involving the sequential formation
of [RuLÂ(CO)Â(CH<sub>3</sub>CN)ÂCl<sub>2</sub>], [RuLÂ(CH<sub>3</sub>CN)<sub>2</sub>Cl<sub>2</sub>], and [RuLÂ(CH<sub>3</sub>CN)<sub>3</sub>Cl]<sup>+</sup>. Release of the first CO molecule occurs quickly (<i>k</i><sub>1</sub> ≫ 3 min<sup>–1</sup>), while
release of the second CO molecule proceeds at a much more modest rate
(<i>k</i><sub>2</sub> = 0.099–0.17 min<sup>–1</sup>) and is slowed by the presence of electron-withdrawing carboxyl
substituents on the bipyridine ligand. In aqueous media (1% dimethyl
sulfoxide in H<sub>2</sub>O), the two photodecarbonylation steps proceed
much more slowly (<i>k</i><sub>1</sub> = 0.46–1.3
min<sup>–1</sup> and <i>k</i><sub>2</sub> = 0.026–0.035
min<sup>–1</sup>, respectively) and the influence of the carboxyl
groups is less pronounced. These results have implications for the
design of new light-responsive CO-releasing molecules (“photoCORMs”)
intended for future medical use
Data for Comprehensive vibrational spectroscopic investigation of trans,trans,trans-[Pt(N3)2(OH)2(py)2], a Pt(IV) diazido anticancer prodrug candidate
We report a detailed study of a promising photoactivatable metal-based anticancer prodrug candidate, trans,trans,trans-[Pt(N3)2(OH)2(py)2] (C1; py = pyridine), using vibrational spectroscopic techniques. Attenuated total reflection Fourier transform infrared (ATR-FTIR), Raman, and synchrotron radiation far-IR (SR-FIR) spectroscopies were applied to obtain highly resolved ligand and Pt-ligand vibrations for C1 and its precursors (trans-[Pt(N3)2(py)2] (C2) and trans-[PtCl2(py)2] (C3)). Distinct IR- and Raman-active vibrational modes were assigned with the aid of density functional theory calculations, and trends in the frequency shifts as a function of changing Pt coordination environment were determined and detailed for the first time. The data provide the ligand and Pt-ligand (azide, hydroxide, pyridine) vibrational signatures for C1 in the mid- and far-IR region, which will provide a basis for the better understanding of the interaction of C1 with biomolecules
Comprehensive Vibrational Spectroscopic Investigation of <i>trans,trans,trans</i>-[Pt(N<sub>3</sub>)<sub>2</sub>(OH)<sub>2</sub>(py)<sub>2</sub>], a Pt(IV) Diazido Anticancer Prodrug Candidate
We
report a detailed study of a promising photoactivatable metal-based
anticancer prodrug candidate, <i>trans</i>,<i>trans</i>,<i>trans</i>-[PtÂ(N<sub>3</sub>)<sub>2</sub>(OH)<sub>2</sub>(py)<sub>2</sub>] (<b>C1</b>; py = pyridine), using vibrational
spectroscopic techniques. Attenuated total reflection Fourier transform
infrared (ATR-FTIR), Raman, and synchrotron radiation far-IR (SR-FIR) spectroscopies
were applied to obtain highly resolved ligand and Pt-ligand vibrations
for <b>C1</b> and its precursors (<i>trans</i>-[PtÂ(N<sub>3</sub>)<sub>2</sub>(py)<sub>2</sub>] (<b>C2</b>) and <i>trans</i>-[PtCl<sub>2</sub>(py)<sub>2</sub>] (<b>C3</b>)). Distinct IR- and Raman-active vibrational modes were assigned
with the aid of density functional theory calculations, and trends
in the frequency shifts as a function of changing Pt coordination
environment were determined and detailed for the first time. The data
provide the ligand and Pt-ligand (azide, hydroxide, pyridine) vibrational signatures for <b>C1</b> in the mid- and
far-IR region, which will provide a basis for the better understanding
of the interaction of <b>C1</b> with biomolecules