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1.
《Inorganica chimica acta》1987,135(3):207-210
An FT-IR spectroscopic study concerning changes in the conformation of sugar in the dinucleotides; GpC and CpG, on platination and intercalation is presented. The results are compared with the FT-IR spectral data of 5′-CMP, 5′-GMP, 3′-GMP and their metal adducts. The spectra of free GpC, free CpG, proflavine-GpC, proflavine-CpG, and cis-[Pt(NH3)2(GpC)2]2+ exhibit the diagnostic band at 800 cm−1 which was assigned to a sugar phosphate vibrational mode and diagnostic of C3′-endo sugar pucker. In the case of 9-aminoacridine-GpC and cis-[Pt(NH3)2(CpG]+ the diagnostic bands of the C2′-endo and C3′-endo conformations are observed at 810–820 cm−1 and near 800 cm−1 respectively. The results are in good agreement with X-ray data. The infrared diagnostic bands are important for distinguishing the sugar pucker conformational changes. 相似文献
2.
《Inorganica chimica acta》1987,128(1):27-29
2′-Deoxy-5′-guanosinemonosphoric acid (B) reacts with cis-[Pt(NH3)2(OH2)2]2+ in two steps to form the cis-[Pt(NH3)2B2]y+ ion. In the first step 2′-d-5′- GMPH2 reacts some ten times faster than 5′-GMPH2 does. Rate constants, ΔH#, ΔS# and ΔV# are very similar for the two bases in the second reaction. It is proposed that the product in the first step contains no water and is cis-[Pt(NH3)2B]x+ in which the nucleobase is bidentate bonding through both N(7) of guanine and an oxygen atom of the phosphate group. 相似文献
3.
《Inorganica chimica acta》1988,153(3):145-153
The blue complexes produced by reaction of cis-diamminediaquoplatinum(II) nitrate, [cis-Pt(NH3)2(H2O)2](NO3)2, with disodium 5′-uridine monophosphate, 5′-UMP(Na2), in H2O and D2O have been investigated by FT-IR spectroscopy. On the basis of the spectral changes observed in the CO stretching region during the reactions, chelation of the amidate N(3)··O(2) moiety to Pt(II) appears to be more likely than N(4)··O(4) chelation. The antisymmetric PO stretching mode of the PO32− group of 5′-UMP splits into a triplet on complex formation indicating that PO32− plays an important role in the structure of the platinum blue complexes. In addition, the sugar moiety of 5′-UMP apparently adopts a predominantly C(3′)-endo conformation in the solid blue complex. Finally, Raman microprobe spectroscopy of the solid provides some evidence for PtN(3) bond formation. 相似文献
4.
The conformational change of the ribose ring in NH4GpG and cis-[Pt(NH3)2(GpG)]+ was confirmed by FT-IR spectroscopic evidence as being C2′-endo, C3′-endo, anti, gg sugar ring pucker in the solid state. These results were compared with 1H NMR spectral data in aqueous solution. The FT-IR spectrum of NH4GpG shows marker bands at 802 cm?1 and 797 cm?1 which are assigned to the C3′-endo, anti, gg sugar-phosphate vibrations of ribose (?pG) and ribose (Gp?), respectively. The FT-IR spectrum of cis-[Pt(NH3)2(GpG)]+ (with N7N7 chelation in the GpG sequence) shows a marker band at 800 cm?1 which is assigned to the C3′-endo, and a new shoulder band at 820 cm?1 related to a C2′-endo ring pucker. The ribose conformation of (?pG) moiety in NH4-GpG, C3′-endo, anti, gg changes into C2′-endo, anti, gg when a platinum atom is chelated to N7N7 in the GpG sequence. 相似文献
5.
1H- and 31P-nmr spectroscopy have been used to investigate the self-association of M2(5′-CMP) [M = Li+, Na+, K+, Rb+, or (CH3)4 N+; 5′-CMP = cytidine 5′-monophosphate], the self-association of Li2(5′-GMP) (5′-GMP = guanosine 5′-monophosphate), and the heteroassociation of 5′-GMP and 5′-CMP (1 : 1 mole ratio) in aqueous solution as a function of the nature of the monovalent cation. Proton spectral differences for the different 5′-CMP salts exhibit a cation-size dependence and have been ascribed to a change in the stacking geometry. An average stacking association constant of 0.63 ± 0.24M?1 at 1°C, consistent with the weak stacking interactions of the cytosine bases, was determined for the 5′-CMP salts. Heteroassociation of 5′-GMP and 5′-CMP follows the reverse of the cation order for the formation of ordered aggregates of 5′-GMP. Heteroassociation occurs in the presence of Li+, Na+, and Rb+ ions, but only self-association occurs for the K+ nucleotides. Li2(5′-GMP), which does not form ordered species, self-associates to form disordered base stacks with a stacking constant of 1.63 ± 0.11M?1 at 1°C. 相似文献
6.
《Inorganica chimica acta》1988,154(1):89-93
[Pt(COD)Cl2] (COD=1,5-cyclooctadiene) is a versatile starting material for the synthesis of Pt(II) compounds. The preparations of the new compounds [Pt(COD)Cl(NO3)], [Pt(COD)(NO3)2] and [Pt(PPh3)3(NO3)](NO3) and also of the known compounds cis[Pt(PPh3)2Cl2], cis [Pt(PPh3)2Cl(NO3)], cis[Pt(PPh3)2(NO3)2] and [Pt(PPh3)3Cl](NO3)are reported. The compounds are characterized by elemental analysis, 31P{1H} NMR spectroscopy and IR spectroscopy. 相似文献
7.
Xizhu Chen Weiping Liu Qingsong Ye Shuqian Hou Yang Liu 《Inorganica chimica acta》2007,360(8):2851-2856
A series of novel platinum(II) complexes involving an asymmetric chelating diamine 2-morpholinoethylamine (MPEA) as the carrier, cis-[Pt(MPEA)X2] (X2 = 2Cl−, oxalate, malonate, 1,1-cyclobutanedicarboxylate (CBDCA), 3-hydroxy-1,1-cyclobutanedicarboxylate (HO-CBDCA)), have been synthesized and characterized by elemental analysis and spectroscopic data along with X-ray crystal structure for a representative complex cis-[Pt(MPEA) (CBDCA)]. The Pt(II) is in a square planar environment and is coordinated by a chelating CBDCA and MPEA in cis position. The complexes with dicarboxylate are quite soluble (>25 mg/ml) and stable in water. The cytotoxicity of the complexes has been assessed in the human lung cancer cell lines A549 and A549/ATCC. One complex, cis-[Pt(MPEA)Cl2], is more active than carboplatin against both the sensitive and resistant cells, and has less cross-resistance with cisplatin. 相似文献
8.
The reaction products of adenosine with [Pt(NH3)3Cl]Cl or cis-Pt(NH3)2Cl2 have been studied using high performance liquid chromatography and uv spectroscopy. The reaction of [Pt(NH3)3Cl]Cl with adenosine (pH = 7.0, Pt/base = 0.5) gives four products. Two of them, mononuclear complexes in which platinum is bound to adenosine through N(7) or N(1), comprise more than 90% of all the products. The N(1) and N(7) sites on adenosine indicate almost equal binding affinity for [Pt(NH3)3Cl]Cl. The reaction of cis-Pt(NH3)2Cl2 with adenosine has been studied in the presence of a large excess of adenosine (Pt/base ? 0.05). The reaction gives four products. One is the monomeric 2:1 complex with cis-Pt(NH3)22+ bound to two adenosine molecules through the N(7) site and the N(1) site, and another is the monomeric 2:1 complex with cis-Pt(NH3)22+ bound to two adenosine molecules through the N(7) sites. cis-Pt(NH3)2Cl2 is stronger affinity to the N(7) site than of adenosine to the N(1) site. 相似文献
9.
Mixed-ligand complexes of the type cis- and trans-Pt(Ypy)(pm)Cl2 where Ypy = pyridine derivative and pm = pyrimidine were synthesized and characterized by IR spectroscopy and by multinuclear (195Pt, 1H and 13C) magnetic resonance spectroscopy. The cis compounds were prepared from the reaction of K[Pt(Ypy)Cl3] with pyrimidine (1:1 proportion) in water, while most of the trans isomers were synthesized from the isomerization of the cis compounds. The cis isomers could not be isolated with the Ypy ligands containing two -CH3 groups in ortho positions. When the aqueous reaction of K[Pt(Ypy)Cl3] with pyrimidine was performed in a Pt:pm ratio = 2:1, the pyrimidine-bridged dinuclear species were formed. Only the most stable trans-trans isomers could be isolated pure. In IR spectroscopy, the cis monomers showed two ν(Pt-Cl) bands, while the trans monomers and dimers showed only one ν(Pt-Cl) band. The 195Pt NMR signals of the cis monomers were found at slightly higher fields than those of the corresponding trans isomers. The δ(195Pt) of the dimers were found close to those of the trans monomers. The NMR results were interpreted in relation to the solvent effect, which seems important in these complexes. The coupling constants J(195Pt-1H) and J(195Pt-13C) are larger in the cis geometry. The crystal structures of the compounds cis-Pt(2,4-lut)(pm)Cl2, trans-Pt(2,6-lut)(pm)Cl2 and trans,trans-Cl2(2,6-lut)Pt(μ-pm)Pt(Ypy)Cl2 were studied by X-ray diffraction methods and the results have confirmed the configurations suggested by IR and NMR spectroscopies. 相似文献
10.
Six new dinuclear complexes, derived from cis-[Co(H2O)2(NH3)4]3+, cis-[Co(H2O)2(en)2]3+ and [M(CN)42? (M = Ni, Pd, Pt) were prepared and characterized by means of chemical analysis, electronic and IR measurements. The influence of the pH on the rate of the reaction was studied for the two derivatives of [Pd(CN)4]2?, showing that the best conditions to obtain the dinuclear compounds are at pH near 6, where the predominant species are cis-[Co(OH)(H2O)(amine)2]2+. The [Pt(CN)4]2? derivatives show PtPt interactions both in the solid state and in solution. 相似文献
11.
The multinuclear (1H, 15N, 31P and 195Pt) NMR spectroscopies, ES-MS and HPLC have been employed to investigate the structure-activity relationship for the reactions between guanosine 5′-monophosphate (5′-GMP) and the platinum(II)-triamine complexes of the general formulation cis-[Pt(NH3)2(Am)Cl]NO3 (where Am represents a substituted pyridine). The order of reaction rate of the reactions was found to be: 3-phpy > 4-phpy > py > 4-mepy > 3-mepy > 2-mepy. The two basic factors, steric and electronic, were attributed to the order of the binding rate constants. A possible mechanism of the reaction of cis-[Pt(NH3)2(Am)Cl]+ with 5′-GMP suggested that the reactions proceed via direct nucleophilic attack and no loss of ammonia. cis-[Pt(NH3)2(Am)Cl]+ binds to the N7 nitrogen of the guanine residue of 5′-GMP to form a coordinate bond with the Pt metal centre. This mechanism is apparently different from that of cisplatin. The pKa value of cis-[Pt(NH3)2(4-mepy)(H2O)](NO3)2 (5.63) has been determined at 298 K by the use of distortionless enhancement by polarization transfer (DEPT) 15N NMR spectroscopy and compared to the pKa value of cis-[PtCl(H2O)(NH3)2]+. 相似文献
12.
Complexes of the types cis- and trans-Pt(amine)2I2 containing cyclic amines were synthesized and studied mainly by IR and multinuclear NMR spectroscopies. The compounds were converted to cis- and trans-Pt(amine)2(NO3)2, which were also investigated. The hydrolysis and the aquation reactions of the latter compounds were then studied in D2O in different conditions of pH. In acidic medium, the aqueous product is [Pt(amine)2(D2O)2]2+ and for a few amines, [Pt(amine)2(D2O)(NO3)]+ was detected. In basic pH, the main product is Pt(amine)2(OD)2 and Pt(amine)2(OD)(NO3) was detected for several compounds. In neutral pH, the cis isomers form between two and four species in fresh solutions. The most shielded species in 195Pt NMR is the monoaqua-monohydroxo complex cis-[Pt(amine)2(D2O)(OD)]+ and the less shielded compound is the dihydroxo-bridged dimer [Pt(amine)2(μ-OD)2Pt(amine)2]2+, which were observed for all the compounds. For a few amines, the monohydroxo-bridged dimer [Pt(D2O)(amine)2(μ-OD)Pt(OD)(amine)2]2+ was detected and for cyclohexylamine, a fourth signal was assigned to a cyclic hydroxo-bridged trimer [(Pt(amine)2(μ-OD))3]3+. 195Pt NMR spectroscopy has shown that the concentration of the monomer decreases with time, while the concentration of the dimers increases. Only one product was observed for the trans isomers in neutral pH. The signal was assigned to the monoaqua-monohydroxo species trans-[Pt(amine)2(D2O)(OD)]+. The 13C and 1H NMR spectra of most of the complexes were measured. All the coupling constants 2,3J(195Pt-1H) and 2,3J(195Pt-13C) are larger in the cis compounds than in the trans isomers. 相似文献
13.
The interactions of cis- and trans-diammineplatinum compounds with 5′-GMP and 5′-dGMP in dilute aqueous solution at neutral pH were investigated by 1H nmr. In addition to the 1:2 Pt nucleotide complexes cis- and trans-Pt(NH3)2(GMP)2, it was possible to study the formation of the 1:1 Pt-nucleotide complexes with either one coordinated water or chloride ion. At 5°C GMP reacts with a stoichiometric amount of cis-diaquodiammine-platinum to yield cis-Pt(NH3)2(GMP) (H2O) as a sole reaction product. From the present results it is concluded that such a complex may play an important role as the initial reaction product between antitumor compounds like cis-Pt(NH3)2Cl2 and guanine in DNA in living organisms. The coupling constant 3J(H(1′)-H(2′)) of the H(1′) sugar proton in cis-Pt(NH3)2(GMP)2 is temperature dependent, indicating a conformational change in the sugar moiety. 相似文献
14.
Various His-Pt(II) coordination compounds were prepared by reaction of K2PtCl4 or cis-[Pt(NH3)2Cl2](cis-DDP) with His and analyzed by 1H and 13C NMR spectroscopy, electrophoresis, and ion-exchange chromatography. His may be coordinated to Pt by the imidazol iminogroup and/or the α-aminogroup; the carboxy group remains always free. Both bidentate as well as monodentate ligands were identified. Cis-DDP reacts with His to give a mixture of compounds where all these possibilities are present: cis-diamine-(histidine-N,N-)Pt(II) and three different types of cis-diammine-bis(histidine). HCl trans cleavage of compounds with bidentate His ligands leads to a mixture of two compounds having His ligated to Pt by an amino or imin group. The methods applied are suitable for analyzing reactions of His with cis-DDP under model conditions similar to physiological conditions. 相似文献
15.
Reaction of cis-[L2Pt(μ-OH)]2(NO3)2 (L = PPh3) with 1-methylthymine (1-MeTy), in DMF, leads to the formation of the mononuclear neutral adduct cis-L2Pt{1-MeTy(-H)}(ONO2) (1) whose structure in the solid state has been obtained by single crystal X-ray diffraction. The deprotonated nucleobase is bounded at the N(3) site, with the pyrimidinic ring almost perpendicular (78.0(1)°) to the metal coordination plane. The fourth ligand is a monodentate nitrate group. Addition of 1 equiv. of 1-methylcytosine (1-MeCy) causes the immediate replacement of the nitrato ligand to form the cationic complex cis-[L2Pt{1-MeTy(-H)}(1-MeCy,N3)]NO3 (2) in which both the nucleobases are N(3)-platinated. In CD2Cl2 at −40 °C 2 exists as a mixture of two conformers (2:1 molar ratio) arising from the different orientation of the nucleobases with respect to the metal coordination plane.In solution of DMSO, DMF or chlorinated solvents, 2 slowly converts into the isomer cis-[L2Pt{1-MeTy(-H)}(1-MeCy,N4)]NO3 (3), containing the tautomeric form of the cytosine stabilised through the coordination at the N(4) atom, as a mixture of conformers whose relative abundance is dependent on the solvent and the temperature.In contrast, the analogous complex of 2 containing the phosphine PMe3, cis-[(PMe3)2Pt{1-MeTy(-H)}(1-MeCy,N3)]NO3 (4), also isolated as pure compound, in DMSO solution slowly rearranges leading to the elimination of the neutral 1-MeTy, with the formation of the dinuclear cytosinate complex cis-[(PMe3)2Pt{1-MeCy(-H),N3N4}]2(NO3)2, previously characterised by us. 相似文献
16.
This study contributes to the investigation related to guest–host interactions between the chemotherapeutic agent cisplatin and a functionalised silica matrix in order to improve and find new materials such as drug carriers. The adsorption of cisplatin and its complexes, cis-[PtCl(NH3)2]+ and cis-[Pt(NH3)2]2+, on a SH-functionalised SiO2(111) surface has been studied by the atom superposition and electron delocalisation method. The adiabatic energy curves for the adsorption of the drug and its products on the delivery system were considered. The electronic structure and bonding analysis were also performed. The molecule and their complex are adsorbed on the functionalised surface resulting in a major absorption of the cis-[Pt(NH3)2]2+ complex. The molecule–surface interactions are formed via –SH group. The molecule/complexes SH electron-donating effect plays an important role in the catalytic reaction. The more important drug–carrier interactions occur through the Cl–H bond for the adsorption of cis-[PtCl2(NH3)2] and cis-[PtCl(NH3)2]+, and through the Pt–S and Pt–H interactions for cis-[Pt(NH3)2]2+ adsorption. When the new interactions are formed, the functionalised carrier maintains their matrix properties while the molecule is the most affected after adsorption. The Pt atomic orbitals present the most important changes during adsorption. 相似文献
17.
Mixed-ligand complexes of the type Pt(amine)(pm)I2, (pm = pyrimidine) were synthesized and characterized by IR spectroscopy and by multinuclear (195Pt, 1H and 13C) magnetic resonance spectroscopy. The cis compounds were prepared from the reaction of I(amine)Pt(μ-I)2Pt(amine)I with pyrimidine (1:2 proportion) in water, while the trans isomers were synthesized from the isomerization of the cis complexes in acetone. The cis isomers could not be isolated with several amines, especially the more bulky ones. In 1H NMR, the pyrimidine protons of the cis compounds were found at lower fields than those of the trans analogs and the J(195Pt-1H) coupling constants are slightly larger in the cis geometry. For n-butylamine, the reaction produced also I2(n-butylamine)Pt(μ-pm)Pt(n-butylamine)I2. No such dimer could be isolated with the other amines. The compounds Pt(amine)(pm)Cl2 were also prepared (amine = methylamine and t-butylamine) from the ionic complex K[Pt(amine)Cl3] using an excess of pyrimidine. The IR and NMR characterization showed that the methylamine compound was a cis-trans mixture, while only the trans isomer was isolated with t-butylamine. When the same reaction was performed using a Pt:pm ratio of 2:1, Cl2(amine)Pt(μ-pm)Pt(amine)Cl2 was isolated. The pyrimidine-bridged dimers were identified by IR and multinuclear magnetic resonance spectroscopies as the trans-trans isomers. The trans monomers and dimers showed only one ν(Pt-Cl) band. The 195Pt NMR signals of the dimers were found close to those of the monomer trans-Pt(amine)(pm)Cl2. 相似文献
18.
《Inorganica chimica acta》1986,124(2):87-96
Complexes formed in aqueous solution between cisplatin or hydrolysis species and 5′ adenosine monophosphate (AMP) or 5′ adenosine triphosphate (ATP), the latter with and without chloride ions, have been determined using 195Pt, 31P, 13C and 1H NMR. The present results lead to the conclusion that the only monodentate complexes with AMP are cis-Pt(NH3)2(AMP-N7)Cl at acid pH and cis-Pt(NH3)2(AMP-N7)OH at neutral and basic pH. Other bidentate complexes were identified as cis-Pt(NH3)2(AMP-N7)2 and cis-Pt(NH3)2(AMP-N7)(AMP-PO). Also discussed herein are the binding of platinum to the phosphate group Pγ with ATP and at acid pH, and the formation of the [cis-Pt(NH3)2(ATP-N7)H2O]+ complex. In neutral and basic pH ranges, the phosphate moiety of ATP is the most reactive site. In the presence of an excess of chloride ions, the complexation rates between the ATP and the cisplatin are decreased. Furthermore, in the experimental conditions used neither the ATP nor the AMP have shown binding to N1. 相似文献
19.
The “amidate-hanging” Pt mononuclear complexes, which can easily bind a second metal ion with the non-coordinated oxygen atoms in the amidate moieties, have been synthesized and characterized by 1H NMR, MS, IR spectroscopy, and single crystal X-ray analysis. Five new complexes with various amidate ligands and co-ligands, cis-[Pt(PVM)2(en)] · 4H2O (1, PVM = pivaloamidate, en = ethylenediamine), cis-[Pt(PVM)2(NH2CH3)2] · H2O (2), cis-[Pt(PVM)2(NH2tBu)2] (3), cis-[Pt(TCM)2(NH3)2] (4, TCM = trichloroacetamidate), and cis-[Pt(BZM)2(NH3)2] (5, BZM = benzamidate), were successfully synthesized by direct base hydrolysis of the corresponding Pt nitrile complexes, cis-[Pt(NCR)2(Am)2]2+ (P1, P2, P3, and P5) (NCR = nitrile, Am = amine). These nitrile complexes were obtained by introducing nitriles into the Pt aqua complexes, cis-[Pt(OH2)2(Am)2](ClO4)2, whereas introduction of trichloronitrile into [Pt(OH2)2(NH3)2](ClO4)2 induced more facilitated water nucleophilic attack to afford [Pt(TCM)(NH(COH)CCl3)(NH3)2](ClO4) (P4). The base treatments of the precursor complexes (P1-5) lead to produce “amidate-hanging” Pt mononuclear complexes (1-5) without geometry isomerization. The 195Pt chemical shifts for 1-5 exhibit subtle differences of the Pt electron densities among them. 相似文献
20.
The nature of the diamine plays a very critical role in stabilizing the cationic species [Pt(η2-C2H4)Cl(diamine)]+ containing a highly reactive olefin. Hence while N,N,N′,N′-tetramethyl-1,2-diaminoethane (tmen) gave a species isolatable in a pure form, N,N,N′,N′-tetramethyl-1,3-diaminopropane (tmpm) and unsubstituted 1,2-diaminoethane (en) were unable to act as bidentate and gave, as isolatable species, only complexes of the type cis-[Pt(η2-C2H4)Cl2(Hdiamine)]+ in which the diamine is protonated and acts as monodentate towards platinum. These results are explained in terms of greater conformational stability of five- versus six-membered chelate rings and of gem-dimethyl substituted towards unsubstituted ring systems (Thorpe-Ingold effect). 相似文献