Guanine nucleobase adducts formed by a monofunctional complex: [Pt(N-(6-methyl-2-picolyl)-N-(2-picolyl)amine)Cl]Cl

Andrepont, Chase; Marzilli, Patricia A.; Pakhomova, Svetlana; Marzillï, Luigi G.

doi:10.1016/j.jinorgbio.2015.06.023

Cited by 10 publications

(11 citation statements)

References 53 publications

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“…Assignments of the AB features/doublets as endo -CH or exo -CH for 5 and 6 (as explained in the Supporting Information) are presented in Figure and Table . The endo -CH signal is normally clearly downfield of the exo -CH signal for 5 , as previously reported for [Pt( N (H)dpa)]Cl and [Pt( N (H)6,6′-Me 2 dpa)]Cl , complexes. For 6 , these signals, which form an overlapped AB pattern, were assigned by studying the temperature dependence of the chemical shifts (see the Supporting Information).…”

Section: Resultssupporting

confidence: 85%

“…This angle, defined as the Pt–N–centroid angle (N = N1 or N3, centroid = aromatic ring center) should approach ∼180°. The Pt–N–centroid angle ranges from 164–180° for known Pt(II) complexes of imidazolyl or pyridyl ligands bound in a monodentate, bidentate, or tridentate fashion. − ,− This angle averages 174.5° for 5 (Table ), which is similar to the value for monodentate ligands (176.7°; see the Supporting Information); this is another indication that the pyridyl rings in 5 are well-positioned to form a strong Pt–N bond.…”

Section: Resultsmentioning

confidence: 72%

“…The structural features of complexes with M–N(sulfonamide) bonds reported in the literature, including the Cu cyclam complexes just discussed, suggest a reason why potentially tridentate ligands 1 and 2 coordinate in a bidentate fashion in Pt(II) complexes 5 and 6 , respectively, even when the complexes are prepared using synthetic approaches known to be successful with related ligands having a central amine N-donor. ,, These observations lead us to propose that a nitrogen atom in a central tertiary sulfonamide group with two adjacent five-membered chelate rings can act as a donor in a tridentate ligand only when the ligand is facially coordinated.…”

Section: Resultsmentioning

confidence: 94%

“…The relevance of binding at G residues in DNA by anticancer-active Pt(II) compounds ,,,, has led to many studies of adduct formation of guanine derivatives ( G ). Mono- and bifunctional Pt(II) chloro complexes bearing carrier ligands with five- and six-membered chelate rings readily form G adducts in various solvents. ,, Upon adduct formation, guanine ligands can even disrupt and open a chelate ring . Surprisingly, the new Pt(II) compounds do not readily form G adducts.…”

Section: Introductionmentioning

confidence: 99%

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Linear Bidentate Ligands (L) with Two Terminal Pyridyl N-Donor Groups Forming Pt(II)LCl₂ Complexes with Rare Eight-Membered Chelate Rings

et al. 2018

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NMR and X-ray diffraction studies were conducted on Pt(II)LCl2 complexes prepared with the new N-donor ligands N(SO2R)Me n dpa (R = Me, Tol; n = 2, 4). These ligands differ from N(H)dpa (di-2-picolylamine) in having the central N within a tertiary sulfonamide group instead of a secondary amine group and having Me groups at the 6,6′-positions (n = 2) or 3,3′,5,5′-positions (n = 4) of the pyridyl rings. The N(SO2R)3,3′,5,5′-Me4dpa ligands are coordinated in a bidentate fashion in Pt(N(SO2R)3,3′,5,5′-Me4dpa)Cl2 complexes, forming a rare eight-membered chelate ring. The sulfonamide N atom did not bind to Pt(II), consistent with indications in the literature that tertiary sulfonamides are unlikely to anchor two meridionally coordinated five-membered chelate rings in solutions of coordinating solvents. The N(SO2R)6,6′-Me2dpa ligands coordinate in a monodentate fashion to form the binuclear complexes [trans-Pt(DMSO)Cl2]2(N(SO2R)6,6′-Me2dpa). The monodentate instead of bidentate N(SO2R)6,6′-Me2dpa coordination is attributed to 6,6′-Me steric bulk. These binuclear complexes are indefinitely stable in DMF-d 7, but in DMSO-d 6 the N(SO2R)6,6′-Me2dpa ligands dissociate completely. In DMSO-d 6, the bidentate ligands in Pt(N(SO2R)3,3′,5,5′-Me4dpa)Cl2 complexes also dissociate, but incompletely; these complexes provide rare examples of association–dissociation equilibria of N,N bidentate ligands in Pt(II) chemistry. Like typical cis-PtLCl2 complexes, the Pt(N(SO2R)3,3′,5,5′-Me4dpa)Cl2 complexes undergo monosolvolysis in DMSO-d 6 to form the [Pt(N(SO2R)3,3′,5,5′-Me4dpa)(DMSO-d 6)Cl]+ cations. However, unlike typical cis-PtLCl2 complexes, the Pt(N(SO2R)3,3′,5,5′-Me4dpa)Cl2 complexes surprisingly do not react readily with the excellent N-donor bioligand guanosine. A comparison of the structural features of over 50 known relevant Pt(II) complexes having smaller chelate rings with those of the very few relevant Pt(II) complexes having eight-membered chelate rings indicates that the pyridyl rings in Pt(N(SO2R)3,3′,5,5′-Me4dpa)Cl2 complexes are well positioned to form strong Pt–N bonds. Therefore, the dissociation of the bidentate ligand and the poor biomolecule reactivity of the Pt(N(SO2R)3,3′,5,5′-Me4dpa)Cl2 complexes arise from steric consequences imposed by the −CH2–N(SO2R)–CH2– chain in the eight-membered chelate ring.

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Section: Resultssupporting

confidence: 85%

Section: Resultsmentioning

confidence: 72%

Section: Resultsmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

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Linear Bidentate Ligands (L) with Two Terminal Pyridyl N-Donor Groups Forming Pt(II)LCl₂ Complexes with Rare Eight-Membered Chelate Rings

et al. 2018

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“…High carrier-ligand bulk leads to decreases in anticancer activity and increases in toxicity of bifunctional platinum(II) anticancer agents, − whereas for monofunctional platinum(II) agents we believe − that high carrier-ligand bulk correlates with increased anticancer activity. − Bifunctional agents, such as cisplatin, form G*G* intrastrand cross-link lesions and cause large distortions in DNA structure, manifested as large changes in CD and NMR , spectra. (G residues in DNA or oligomers with a Pt(II) center bound to N7 are designated as G*).…”

Section: Introductionmentioning

confidence: 99%

A Very Rare Example of a Structurally Characterized 3′-GMP Metal Complex. NMR and Synthetic Assessment of Adducts Formed by Guanine Derivatives with [Pt(L^tri)Cl]Cl Complexes with an N,N′,N″ Tridentate Ligand (L^tri) Terminated by Imidazole Rings

et al. 2017

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[Pt(N(R)-1,1'-Medma)Cl]Cl complexes with tridentate ligands (bis(1-methyl-2-methylimidazolyl)amine, R = H; N-(methyl)bis(1-methyl-2-methylimidazolyl)amine, R = Me) were prepared in order to investigate Pt(N(R)-1,1'-Medma)G adducts (G = monodentate N9-substituted guanine or hypoxanthine derivative). Solution NMR spectroscopy is the primary tool for studying metal complexes of nucleosides and nucleotides because such adducts rarely crystallize. However, [Pt(N(H)-1,1'-Medma)(3'-GMPH)]NO·5HO (5) was crystallized, allowing, to our knowledge, the first crystallographic molecular structure determination for a 3'-GMP platinum complex. The structure is one of only a very few structures of a 3'-GMP complex with any metal. Complex 5 has the syn rotamer conformation, with 3'-GMP bound by N7. All Pt(N(R)-1,1'-Medma)G adducts exhibit two new downfield-shifted G H8 signals, consistent with G bound to platinum by N7 and a syn/anti rotamer mixture. Anticancer-active monofunctional platinum(II) complexes have bulky carrier ligands that cause DNA adducts to be distorted. Hence, understanding carrier-ligand steric effects is key in designing new platinum drugs. Ligand bulk can be correlated with the degree of impeded rotation of the G nucleobase about the Pt-N7 bond, as assessed by the observation of rotamers. The signals of syn and anti rotamers are connected by EXSY cross-peaks in 2D ROESY spectra of Pt(N(H)-1,1'-Medma)G adducts but not in spectra of Pt(N(H)dpa)G adducts (N(H)dpa = bis(2-picolyl)amine), indicating that rotamer interchange is more facile and carrier-ligand bulk is lower in Pt(N(H)-1,1'-Medma)G than in Pt(N(H)dpa)G adducts. The lower steric hindrance is a direct consequence of the greater distance of the G nucleobase from the H4/4' protons in the N(R)-1,1'-Medma carrier ligand in comparison to that from the H6/6' protons in the N(H)dpa carrier ligand. Although in 5 the nucleotide is 3'-GMP (not the usual 5'-GMP) and the N(H)-1,1'-Medma carrier ligand is very different from those typically present in structurally characterized Pt(II) G complexes, the rocking and canting angles in 5 adhere to long-recognized trends.

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Phosphorescent Trinuclear Pt–Ir–Pt Complexes: Insights into the Photophysical and Electrochemical Properties and Interaction with Guanine Nucleobase

Das

Borah

Ganguli

et al. 2020

Chemistry A European J

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In this studyw eh ave analysed the comparative photophysical and electrochemical properties of two isomeric heterotrinuclear Pt II-Ir III-Pt II complexes 3 and 6 and the four corresponding intermediate isomeric homonuclear cyclometalated iridium(III) complexes 1, 2, 4 and 5.T he isomerisation originates from positional differences in the formyl,d i-2-picolylamine and Pt-di-2-picolylaminem oieties appended to cyclometalated or ancillary ligands.The interaction of 5'-GMP with the trinuclearc omplexes 3 and 6 shows that platinumc entres appended to the cyclometalated ligandi n3 facilitatet he binding of two 5'-GMPu nits per Pt II centrei npreference to as ingle 5'-GMP unit per Pt II centre as observed in 6.T he 1:2a nd 1:1P t II-5'-GMP binding patterns probablya rise from the convenient arrangements of the Ptdi-2-picolylamine units in different planes in complex 3, whichi sa bsentinc omplex 6.

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Guanine nucleobase adducts formed by a monofunctional complex: [Pt(N-(6-methyl-2-picolyl)-N-(2-picolyl)amine)Cl]Cl

Cited by 10 publications

References 53 publications

Linear Bidentate Ligands (L) with Two Terminal Pyridyl N-Donor Groups Forming Pt(II)LCl₂ Complexes with Rare Eight-Membered Chelate Rings

Linear Bidentate Ligands (L) with Two Terminal Pyridyl N-Donor Groups Forming Pt(II)LCl₂ Complexes with Rare Eight-Membered Chelate Rings

A Very Rare Example of a Structurally Characterized 3′-GMP Metal Complex. NMR and Synthetic Assessment of Adducts Formed by Guanine Derivatives with [Pt(L^tri)Cl]Cl Complexes with an N,N′,N″ Tridentate Ligand (L^tri) Terminated by Imidazole Rings

Phosphorescent Trinuclear Pt–Ir–Pt Complexes: Insights into the Photophysical and Electrochemical Properties and Interaction with Guanine Nucleobase

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Guanine nucleobase adducts formed by a monofunctional complex: [Pt(N-(6-methyl-2-picolyl)-N-(2-picolyl)amine)Cl]Cl

Cited by 10 publications

References 53 publications

Linear Bidentate Ligands (L) with Two Terminal Pyridyl N-Donor Groups Forming Pt(II)LCl2 Complexes with Rare Eight-Membered Chelate Rings

Linear Bidentate Ligands (L) with Two Terminal Pyridyl N-Donor Groups Forming Pt(II)LCl2 Complexes with Rare Eight-Membered Chelate Rings

A Very Rare Example of a Structurally Characterized 3′-GMP Metal Complex. NMR and Synthetic Assessment of Adducts Formed by Guanine Derivatives with [Pt(Ltri)Cl]Cl Complexes with an N,N′,N″ Tridentate Ligand (Ltri) Terminated by Imidazole Rings

Phosphorescent Trinuclear Pt–Ir–Pt Complexes: Insights into the Photophysical and Electrochemical Properties and Interaction with Guanine Nucleobase

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Linear Bidentate Ligands (L) with Two Terminal Pyridyl N-Donor Groups Forming Pt(II)LCl₂ Complexes with Rare Eight-Membered Chelate Rings

Linear Bidentate Ligands (L) with Two Terminal Pyridyl N-Donor Groups Forming Pt(II)LCl₂ Complexes with Rare Eight-Membered Chelate Rings

A Very Rare Example of a Structurally Characterized 3′-GMP Metal Complex. NMR and Synthetic Assessment of Adducts Formed by Guanine Derivatives with [Pt(L^tri)Cl]Cl Complexes with an N,N′,N″ Tridentate Ligand (L^tri) Terminated by Imidazole Rings