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[Gd(HP‐DO3A)] (gadoteridol) as an active compound of ProHance® is a widely employed contrast agent in clinical MRI scans in the last 30 years. Recent concerns about the long‐term retention of gadolinium‐based contrast agents (GBCAs) led to a deeper investigation of the structural features underlying the integrity of the paramagnetic metal complex. Several human and nonclinical studies have noted marked differences among the macrocyclic GBCAs, with the least retention of Gd traces and most rapid elimination consistently being reported for [Gd(HP‐DO3A)]. It was deemed of interest to assess how minor structural/electronic changes associated to the ligand structure may affect basic properties of the metal complex with several [Gd(HP‐DO3A)] analogues synthesized and characterized in the last years. We recently reported that the closest homolog of [Gd(HP‐DO3A)], i. e.: [Gd(HB‐DO3A)], in which a (±)‐2‐hydroxy‐1‐propyl pendant arm is replaced by a (±)‐2‐hydroxy‐1‐butyl moiety, showed a significantly different retention behaviour in the model interaction with collagen, despite the apparently very minor structural difference. In this paper we report a comprehensive study of the structural, thermodynamic, kinetic and relaxation properties of [Gd(HB‐DO3A)], compared to the parent [Gd(HP‐DO3A)] and to other closely related macrocyclic GBCAs to assess whether very minor structural changes can modulate the physico‐chemical properties of Gd3+ complexes. [ABSTRACT FROM AUTHOR]

In view of developing artificial light‐responsive complex systems, the preparation of discrete and robust heteroleptic assemblies of different chromophores in precisely defined positions is of great value since they would allow to investigate directional processes unavailable in symmetrical architectures. Here we describe the preparation, through a modular stepwise approach, and characterization of four novel and robust metal‐mediated heteroleptic 4+3 porphyrin tapes, labeled D4−T4−D4, D3−T4−D3, D4−T3−D4, and D3−T3−D3, where a central meso‐tetrapyridylporphyrin (either 3′‐TPyP=T3 or 4′‐TPyP=T4) is connected to two equal cis‐dipyridylporphyrins (either 3′cisDPyMP=D3 or 4′cisDPyMP=D4) through four {t,c,c‐RuCl2(CO)2} fragments. Whereas D4−T4−D4 is flat, the tapes containing at least one 3′PyP, i. e. D3−T4−D3, D4−T3−D4, and D3−T3−D3, have unprecedented – and well defined – 3D geometries, and each exists in solution as a pair of stereoisomers in slow conformational equilibrium. The X‐ray molecular structures of two such conformers, the C‐shaped (D3−T4−D3)C and the z‐shaped (D4−T3−D4)z, were determined and are fully consistent with the solution NMR findings. [ABSTRACT FROM AUTHOR]

Treatment of the Ru(II) precursor cis,cis,trans‐[RuCl2(dmso‐S)2(PTA)2] (1, PTA=1,3,5‐triaza‐7‐phosphaadamantane) with 2,2′‐bipyridine (bpy) in refluxing ethanol selectively affords cis,cis‐[Ru(bpy)Cl2(PTA)2] (2), whereas with pyridine (py), under the same conditions, it gives trans,cis,cis‐[RuCl2(PTA)2(py)2] (6). The slightly less stable stereoisomer of 2, cis,trans‐[Ru(bpy)Cl2(PTA)2] (3), is obtained selectively through a different synthetic route. Isomers 2 and 3 are thermally stable, but cleanly equilibrate upon irradiation of an aqueous solution of either one with blue light. Intrigued by the stereoisomeric outcome in the preparations of this homogeneous set of complexes, we also investigated 2, 3, and 6 (and the mono‐pyridine complex trans,mer‐[RuCl2(py)(PTA)3] (7)) through a topological analysis of the electron density map using the quantum theory of atoms in molecules (QTAIM). The wealth of acquired experimental and calculated data allow us to discuss the stereochemical preferences of the [RuCl2(PTA)2(2 L)] complexes (2 L=bpy or 2py) in terms of electronic and steric contributions. The results of this speculative study on model complexes are transferable to similar systems. As an example, our findings from the reactivity of 1 towards pyridine allowed us to prepare the 2+2 pyridylporphyrin metallacycle trans,cis,cis‐[RuCl2(PTA)2(4′‐cisDPyP)]2 (10, 4′‐cisDPyP=5,10‐(4′‐pyridyl)‐15,20‐(phenyl)‐porphyrin), whose X‐ray molecular structure is also reported. [ABSTRACT FROM AUTHOR]

Cancer is one of the main causes of death worldwide. Chemotherapy, despite its severe side effects, is to date one of the leading strategies against cancer. Metal‐based drugs present several potential advantages when compared to organic compounds and they have gained trust from the scientific community after the approval on the market of the drug cisplatin. Recently, we reported the ruthenium complex ([Ru(DIP)2(sq)](PF6) (where DIP is 4,7‐diphenyl‐1,10‐phenantroline and sq is semiquinonate) with a remarkable potential as chemotherapeutic agent against cancer, both in vitro and in vivo. In this work, we analyse a structurally similar compound, namely [Ru(DIP)2(mal)](PF6), carrying the flavour‐enhancing agent approved by the FDA, maltol (mal). To possess an FDA approved ligand is crucial for a complex, whose mechanism of action might include ligand exchange. Herein, we describe the synthesis and characterisation of [Ru(DIP)2(mal)](PF6), its stability in solutions and under conditions that resemble the physiological ones, and its in‐depth biological investigation. Cytotoxicity tests on different cell lines in 2D model and on HeLa MultiCellular Tumour Spheroids (MCTS) demonstrated that our compound has higher activity than cisplatin, inspiring further tests. [Ru(DIP)2(mal)](PF6) was efficiently internalised by HeLa cells through a passive transport mechanism and severely affected the mitochondrial metabolism. [ABSTRACT FROM AUTHOR]

This contribution, that readdresses the insertion of the RuII–CO fragment into model porphyrins (i.e. ruthenation), has a Janus character, with one speculative and one practical side. As a proof of concept we demonstrate that ruthenation of a porphyrin can be performed under relatively mild conditions using the RuII monocarbonyl complex [Ru(CO)(dmso)5][PF6]2 that – besides CO – features exclusively labile dmso ligands. Even though this finding might seem trivial, it is only the second example that uses a RuII carbonyl for porphyrin ruthenation, the first one having been reported almost 50 years ago and then neglected. From a practical point of view, we show the spectacular effect of propionic acid as solvent for performing the ruthenation of neutral and anionic model porphyrins with Ru3(CO)12 (1). This process turned out to be extremely efficient and advantageous in terms of both reaction rates and yields (e.g. 100 % ruthenation of TPP in 30 min at 140 °C) compared to the procedures described in the literature. [ABSTRACT FROM AUTHOR]

Three new Ru(ii) bioconjugates with the C-terminal hexapeptide sequence of neurotensin, RRPYIL, namely trans,cis-RuCl2(CO)2(cppH-RRPYIL-κNp) (7), [Ru([9]aneS3)(cppH-RRPYIL-κNp)(PTA)](Cl)2 (8), and [Ru([9]aneS3)Cl(cppH-RRPYIL-κNp)]Cl (11), where cppH is the asymmetric linker 2-(2′-pyridyl)pyrimidine-4-carboxylic acid, were prepared in pure form and structurally characterized in solution. The cppH linker is capable of forming stereoisomers (i.e. linkage isomers), depending on whether the nitrogen atom ortho (No) or para (Np) to the carboxylate on C4 in the pyrimidine ring binds the metal ion. Thus, one of the aims of this work was to obtain pairs of stereoisomeric conjugates and investigate their biological (anticancer, antibacterial) activity. A thorough NMR characterization clearly indicated that in all cases exclusively Np conjugates were obtained in pure form. In addition, the NMR studies showed that, whereas in DMSO-d6 each conjugate exists as a single species, in D2O two (7) or even three if not four (8 and 11) very similar stable species form (each one corresponding to an individual compound). Similar results were observed for the cppH-RRPYIL ligand alone. Overall, the NMR findings are consistent with the occurrence of a strong intramolecular stacking interaction between the phenol ring of tyrosine and the pyridyl ring of cppH. Such stacking interactions between aromatic rings are expected to be stronger in water. This interaction leads to two stereoisomeric species in the free cppH-RRPYIL ligand and in the bioconjugate 7, and is somehow modulated by the less symmetrical Ru coordination environments in 8 and 11, affording three to four very similar species. [ABSTRACT FROM AUTHOR]

The reaction of the antimetastatic ruthenium(iii) drug NAMI A with human H-chain ferritin (HuHf) was investigated through a variety of biophysical methods. We observed that the addition of HuHf to NAMI A solutions significantly increases the rate of spontaneous NAMI A hydrolysis suggesting the occurrence of a direct metallodrug–protein interaction. The resulting hydrolyzed Ru species binds the protein mostly forming a relatively tight 1 : 1 ruthenium/ferritin (subunit) adduct that was then separated and characterized. Notably, this adduct shows a characteristic CD spectrum in the visible region, which is diagnostic of the existence of at least one protein bound ruthenium center. The crystal structure of this NAMI A/HuHf adduct was subsequently solved at 1.58 Å resolution; clear evidence is given for the selective binding of a single Ru ion to His105 of each subunit with concomitant release of all other original Ru ligands in agreement with previous observations. We also noted that NAMI A produces a partial inhibition of HuHf ferroxidase activity. The implications of the above results are discussed. [ABSTRACT FROM AUTHOR]

This paper is a tribute to the rich chemistry and great versatility of ruthenium‐dmso precursors: over the years, from a handful of complexes we prepared literally hundreds of derivatives with all types of ligands, from mono‐ to polydentate, from pure σ‐donors (e.g. NH3) to phosphines and strong π‐acceptors such as CO and NO. This systematic and extensive investigation had a thread of thought running through it: the identification of compounds that might have functional roles, either because they possess peculiar physical‐chemical properties or because they undergo predictable and stereo‐controlled substitution reactions, that is, they are well‐behaved precursors. From a more fundamental point of view, this systematic investigation led us to get a deeper understanding of the subtle differences in the soft nature of ruthenium and osmium, as well as in the delicate balance between electronic and steric preferences of the dmso ligand and of its remarkable adaptability to the coordination environment. [ABSTRACT FROM AUTHOR]

A series of water-soluble photolabile model complexes of the general formula [Ru([9]aneS3)(chel)(py)]Cl2 ([9]aneS3 = 1,4,7-trithiacyclononane, chel = chelating diimine) was prepared and fully characterized. The phototriggered release of pyridine with visible light as a function of the nature of the diimine {chel = 2,2'-bipyridine (6) 1,10-phenanthroline (7), 4,7-diphenil-1,10-phenanthroline (8), dipyrido-[3,2-a:2',3'-c]- phenazine (dppz, 9), 2,2'-biquinoline (bq, 10)} was investigated. Our aim is to establish whether this type of complexes might be realistically used in the photo-uncaging strategy of photoactivated chemotherapy (PACT) in the future. Compounds 6-9 present a MLCT absorption in the blue region of the visible spectrum. When irradiated with light at 470 nm, they rapidly and quantitatively release the coordinated pyridine. Complex 10 turned out to be quite different from the others in the series. Structure-wise, in 10 the average plane of coordinated bq - owing to its steric demand - is remarkably tilted relative to the equatorial coordination plane [37.43(4)°, with the "front" of the ligand pointing towards the axial py] and the orientation of py is nearly orthogonal compared to that found in 6 and 7 for minimizing steric clashes with bq. The low-lying acceptor orbitals of bq induce a red-shift of the MLCT absorption maximum to ca. 500 nm. Contrary to the expectations, complex 10 is more photostable compared to 6-9 and photo-dissociation of both py and bq, in nearly equal amounts, occurs. A detailed theoretical investigation was performed on 10 (and on 6 for comparison), for explaining its peculiar spectral features and photochemical behavior. [ABSTRACT FROM AUTHOR]

As anticipated in the title, this contribution is basically divided into two, strictly connected, parts. The first is a personal overview of the ruthenium drug candidate NAMI-A, almost 30 years after its synthesis and the discovery of its unprecedented antimetastatic properties in animal models at nontoxic dosages. The sections relating to the chemical and biological behavior of the complex, and the hypotheses on its mechanism(s) of action, are kept to a minimum, whereas more space is devoted to discussion of the results of the clinical investigations. The second part deals in detail with a number of undemonstrated misconceptions (or myths) that, over the years, have thrived around NAMI-A and other ruthenium drug candidates, thus negatively affecting the whole field of Ru anticancer drugs. [ABSTRACT FROM AUTHOR]

The monodentate phosphane ligand 1,3,5-triaza-7-phosphaadamantane (PTA) imparts excellent water solubility to its complexes. We aimed to prepare precursors with one or more PTA coligands for solubility and one or more labile ligands for facile replacement by a linker. For this purpose, we investigated the reactivity of the neutral isomers trans- and cis-RuCl2(PTA)4 ( 1 and 2) towards 2,2′-bipyridine (bpy), as a model chelating diimine linker. The new derivatives mer-[Ru(bpy)Cl(PTA)3]Cl ( 9) and fac-[Ru(bpy)Cl(PTA)3]Cl ( 10) were prepared and characterized. We also found that PTA reacts rapidly with cis, fac-RuCl2(dmso- O)(dmso- S)3 ( 11) and trans-RuCl2(dmso- S)4 ( 13) under mild conditions through the replacement of pairs of mutually trans dmso ligands with high selectivity, even when in stoichiometric defect. Thus, 11 affords cis, cis, trans-RuCl2(dmso- S)2(PTA)2 ( 12), whereas 13 gives 1. The two dmso ligands of 12 can be replaced selectively by chelating diimines such as bpy to afford the less symmetrical all- cis product cis, cis-Ru(bpy)Cl2(PTA)2 ( 16). [ABSTRACT FROM AUTHOR]

We investigated the reactivity of three Ru(ii) precursors –trans,cis,cis-[RuCl2(CO)2(dmso-O)2], cis,fac-[RuCl2(dmso-O)(dmso-S)3], and trans-[RuCl2(dmso-S)4] – towards the diimine linker 2-(2′-pyridyl)pyrimidine-4-carboxylic acid (cppH) or its parent compound 4-methyl-2-(2′-pyridyl)pyrimidine ligand (mpp), in which a methyl group replaces the carboxylic group on the pyrimidine ring. In principle, both cppH and mpp can originate linkage isomers, depending on how the pyrimidine ring binds to ruthenium through the nitrogen atom ortho (No) or para (Np) to the group in position 4. The principal aim of this work was to establish a spectroscopic fingerprint for distinguishing the coordination mode of cppH/mpp also in the absence of an X-ray structural characterization. By virtue of the new complexes described here, together with the others previously reported by us, we successfully recorded {1H,15N}-HMBC NMR spectra at natural abundance of the 15N isotope on a consistent number of fully characterized Ru(ii)–cppH/mpp compounds, most of them being stereoisomers and/or linkage isomers. Thus, we found that 15N NMR chemical shifts unambiguously establish the binding mode of cppH and mpp – either through No or Np– and can be conveniently applied also in the absence of the X-ray structure. In fact, coordination of cppH to Ru(ii) induces a marked upfield shift for the resonance of the N atoms directly bound to the metal, with coordination induced shifts (CIS) ranging from ca.−45 to −75 ppm, depending on the complex, whereas the unbound N atom resonates at a frequency similar to that of the free ligand. Similar results were found for the complexes of mpp. This work confirmed our previous finding that cppH has no binding preference, whereas mpp binds exclusively through Np. Interestingly, the two cppH linkage isomers trans,cis-[RuCl2(CO)2(cppH-κNp)] (5) and trans,cis-[RuCl2(CO)2(cppH-κNo)] (6) were easily obtained in pure form by exploiting their different solubility properties. [ABSTRACT FROM AUTHOR]

This work demonstrates how a careful reexamination of well-trodden fields can fill conceptual gaps that previously escaped full understanding. The coordination of 2,2′-bipyridine (bpy) to the known RuII-chlorido-carbonyl precursors - the dinuclear [RuCl2(CO)3]2 ( P1) and the polymeric [RuCl2(CO)2] n ( P2) - has been investigated by several groups in the past, and a remarkably large number of ruthenium-mono(bpy)-carbonyl compounds were identified and fully characterized. Many were investigated as catalysts or key intermediates for the photochemical, electrochemical, and photo-electrochemical reduction of CO2, and for the water-gas shift reaction. Nevertheless, even though most - if not all - of the reaction products are known already, a careful examination of the literature led us to believe that a convincing general scheme interconnecting them all was still missing and important questions remained unanswered. For this reason, we investigated the reactivity of two mononuclear RuII-carbonyl-dmso precursors, trans, cis, cis-[RuCl2(CO)2(dmso-O)2] ( P3) and fac-[RuCl2(CO)3(dmso-O)] ( P4) - which can be considered as 'activated forms' of P2 and P1, respectively - towards the coordination of bpy. Compounds P3 and P4 allowed us to gain new mechanistic insight and a deeper level of understanding. In particular, we found that coordination of bpy to P4 (or P1) generates first the tricarbonyl cation fac-[Ru(bpy)Cl(CO)3]+. This key intermediate undergoes the facile and selective nucleophilic attack on the CO trans to Cl (by RO- in alcoholic solvents or OH- from adventitious water in other solvents), leading to all other species. We also demonstrated that Cl- - even when in large excess - is unable to replace a carbonyl on fac-[Ru(bpy)Cl(CO)3]+. However, the chloride set free from the precursor competes efficiently with bpy for the coordination to RuII ( chloride rebound mechanism). [ABSTRACT FROM AUTHOR]

Background This phase I/II study determined the maximal tolerable dose, dose limiting toxicities, antitumor activity, the pharmacokinetics and pharmacodynamics of ruthenium compound NAMI-A in combination with gemcitabine in Non-Small Cell Lung Cancer patients after first line treatment. Methods Initial dose escalation of NAMI-A was performed in a 28 day cycle: NAMI-A as a 3 h infusion through a port-a-cath at a starting dose of 300 mg/m at day 1, 8 and 15, in combination with gemcitabine 1,000 mg/m at days 2, 9 and 16. Subsequently, dose escalation of NAMI-A in a 21 day schedule was explored. At the maximal tolerable dose level of this schedule an expansion group was enrolled of which 15 patients were evaluable for response. Results Due to frequent neutropenic dose interruptions in the third week, the 28 day schedule was amended into a 21 day schedule. The maximal tolerable dose was 300 and 450 mg/m of NAMI-A (21 day schedule). Main adverse events consisted of neutropenia, anemia, elevated liver enzymes, transient creatinine elevation, nausea, vomiting, constipation, diarrhea, fatigue, and renal toxicity. Conclusion NAMI-A administered in combination with gemcitabine is only moderately tolerated and less active in NSCLC patients after first line treatment than gemcitabine alone. [ABSTRACT FROM AUTHOR]

The article discusses a study that focuses on the discovery of a ruthenium complex NAMI-A which exhibits potent and selective cytotoxic effects toward leukaemia cell lines. Topics discussed include the structure of the complex that consists of four equatorial chloride ligands, blockade of calcium activated potassium channels due to the antiproloferative effects of the complex and low probability of toxicity when taken in high doses.

Six half-sandwich RuII coordination compounds of the general formula [Ru([9]aneS3)(L-L)(L′)][PF6] n { 2- 7; [9]aneS3 = 1,4,7-trithiacyclononane, L-L = 2,2′-bipyridine (bpy), 1,2-diaminoethane (en), (±)- trans-1,2-diaminocyclohexane (dach), picolinate (pic); L′ = pyridine (py), 3-acetylpyridine (3-acpy), imidazole (im); n = 1 or 2, depending on the nature of L-L} were prepared and characterized. If irradiated with blue light ( λ = 400-490 nm) in aqueous solution, they readily dissociate the monodentate L′ ligand to generate selectively the corresponding aqua species. The extent and rate of photoinduced ligand release depend primarily on the nature of the chelating ligand (bpy >> en ≈ dach > pic) and, to a minor extent, on that of the leaving ligand (py > im > 3-acpy). Photolabile compounds 2- 5 showed no significant antiproliferative activity against the MDA-MB-231 human mammary carcinoma cell line, both in the dark and upon irradiation with blue light. The clean photodissociation process that characterizes this class of half-sandwich RuII compounds, and the substantial lack of toxicity of the photogenerated Ru aqua species, suggest that they might be suitable for the preparation of 'caged' RuII compounds. In the frame of this work, two unexpected dinuclear compounds, namely, [{Ru([9]aneS3)(en)}2(μ-en)][CF3SO3]4 ( 9) and [{Ru([9]aneS3)}2(μ-dach)(μ-CH3O)2][CF3SO3]2 ·2CH3OH ( 10)-both containing rare examples of bridging en and dach ligands-were also isolated and structurally characterized. [ABSTRACT FROM AUTHOR]

The Ru(ii) complex fac-[RuCl(dmso-S)3(dmso-O)2][PF6] (P2) was found to be an excellent precursor for the facile preparation in high yield of half sandwich-type compounds of the general formula fac-[RuCl(dmso-S)3(N)2][PF6] (e.g.(N)2= 1,2-diaminoethane (en, 4), trans-1,2-diaminocyclohexane (dach, 5), or 2 NH3(6)). Neutral half sandwich-type compounds of the general formula fac-[RuCl(dmso-S)3(N–O)] where N–Ois an anionic chelating ligand (e.g. N–O= picolinate (pic, 7)) are best prepared from the universal Ru(ii)-dmso precursor cis-[RuCl2(dmso)4] (P1). These complexes, that were fully characterized in solution and in the solid state, are structurally similar to the anticancer organometallic compounds [Ru(η6-arene)(chel)Cl][PF6]nbut, in place of a face-capping arene, have the fac-Ru(dmso-S)3fragment. In contrast to what observed for the corresponding arene compounds, that rapidly hydrolyze the Cl ligand upon dissolution in water, compounds 4–6are very stable and inert in aqueous solution. Probably their inertness is the reason why they showed no significant cytotoxicity against the MDA-MB-231 cancer cell line. [ABSTRACT FROM AUTHOR]

There is substantial recent interest worldwide in the construction of multiporphyrin assemblies which can either mimic naturally occurring multichromophore aggregates, such as the photosynthetic reaction center and the light harvesting complex of purple bacteria, or which can be used as electron- and/or energy-transfer molecular devices for advanced technological tasks. The metal-mediated self-assembly approach, which exploits the formation of coordination bonds between peripheral basic site(s) on the porphyrins and metal centers, has recently allowed the design and preparation of sophisticated supramolecular architectures whose complexity and function begin to approach the properties of naturally occurring systems. Within this framework, meso -pyridyl/phenyl porphyrins (PyPs), or strictly related chromophores, can provide geometrically well-defined connections to as many as four metal centers by coordination of the pyridyl groups. Several discrete assemblies of various nuclearities, in which the pyridylporphyrins are linkers binding metalloporphyrins and/or coordination compounds, have been constructed in recent years. Our contribution to this field is reviewed, with the aim of providing insight into the design of new, more elaborated architectures of higher order. [ABSTRACT FROM AUTHOR]

Modifications of natural DNA by three anticancer heterocyclic ruthenium(III) compounds were studied by methods of molecular biophysics. These methods included DNA binding studies using atomic absorption spectrophotometry, inhibition of restriction endonucleases, mapping of DNA adducts by transcription assay, interstrand cross-linking employing gel electrophoresis under denaturing conditions, DNA unwinding studied by gel electrophoresis, circular dichroism analysis of the B→Z transition in DNA, and DNA melting curves measured by absorption spectrophotometry. The results indicate that the complexes HIm[ trans-Cl4Im2RuIII], HInd[ trans-Cl4Ind2RuIII], and Na[ trans-Cl4Im(Me2SO)RuIII] (Im and Ind stand for imidazole and indazole, respectively) coordinate irreversibly to DNA. Their DNA binding mode is, however, different from that of cisplatin. Interestingly, Na[ trans-Cl4Im(Me2SO)RuIII] binds to DNA considerably faster than the other two ruthenium compounds and cisplatin. In addition, when Na[ trans-Cl4Im(Me2SO)RuIII] binds to DNA it exhibits an enhanced base sequence specificity in comparison with the other two ruthenium complexes. Na[ trans-Cl4Im(Me2SO)RuIII] also forms bifunctional intrastrand adducts on double-helical DNA which are capable of terminating RNA synthesis in vitro, while the capability of the other two ruthenium compounds to form such adducts is markedly lower. This observation has been interpreted to mean that the bifunctional adducts of HInd[ trans-Cl4Ind2RuIII] and Na[ trans-Cl4Im2RuIII] formed on rigid double-helical DNA are sterically more crowded by their octahedral geometry than those of Na[ trans-Cl4Im(Me2SO)RuIII]. In addition, the adducts of all three ruthenium compounds affect the conformation of DNA, Na[ trans-Cl4Im(Me2SO)RuIII] being most effective. It has been suggested that the altered DNA binding mode of ruthenium compounds in comparison with cisplatin might be an important factor responsible for the altered cytostatic activity of this class of ruthenium compounds in tumor cells. [ABSTRACT FROM AUTHOR]

Examines the reaction of Na[transRuCl[sub 4]Me[sub 2]SO(Im)] (NAMI) with bovine serum albumin (BSA) using physico-chemical techniques. Binding of NAMI with BSA after chloride hydrolysis; Spectroscopic features of ruthenium centers; Equivalents produced by NAMI.