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Mavroudis A. Demertzis

Bio: Mavroudis A. Demertzis is an academic researcher from University of Ioannina. The author has contributed to research in topics: Palladium & Crystal structure. The author has an hindex of 32, co-authored 72 publications receiving 2729 citations.


Papers
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Journal ArticleDOI
TL;DR: Among these compounds, the most effective in inducing antitumour and cytogenetic effects are the complexes [Pt(AcTsc)(2)] and [Pd(Ac tsc)( 2)] while the rest, display marginal cytogenetics and antitumours effects.

198 citations

Journal ArticleDOI
TL;DR: The complexes 1-6 were found to exhibit a cytotoxic potency in a very low micromolar range and to be able to overcome the cisplatin resistance of A2780/Cp8 cells.
Abstract: The reactions of Pd(II) and Pt(II) with 2-Acetyl Pyridine N(4)-Ethyl-Thiosemicarbazones, HAc4Et and 2-Acetyl Pyridine N(4)-1-(2-pyridyl)-piperazinyl Thiosemicarbazone, HAc4PiPiz and 2-Formyl Pyridine N(4)-1-(2-pyridyl)-piperazinyl Thiosemicarbazone, HFo4PiPiz afforded the complexes, [Pd(Ac4Et)], 1, [Pd(HAc4Et)2]Cl2, 2 and [Pd(Ac4Et)2], 3 [Pt(Ac4Et)], 4, [Pt(HAc4Et)2]Cl2, 5, [Pt(Ac4Et)2], 6 and [Pd(Fo4PipePiz)Cl], 7, [Pd(Fo4PipePiz)2], 8, [Pd(Ac4PipePiz)Cl], 9 and [Pd(Ac4PipePiz)2], 10. The crystal structure of the complex [Pt(Ac4Et)2], 6 has been solved. The platinum(II) atom is in a square planar environment surrounded by two cis nitrogen atoms and two cis sulfur atoms. The ligands are not equivalent, one being tridentate with (N,N,S) donation, the other being monodentate using only the sulfur atom to coordinate to the metal. The tridentate ligand shows a Z, E, Z configuration while the monodentate ligand shows an E, E, Z. Inter-molecular hydrogen bonds stabilize the structure, while the crystal packing is determined by pi-pi, and Pt-C interactions. The antibacterial effect of Pd(II) and Pt(II) complexes were studied in vitro. The complexes were found to have effect on Gram(+) bacteria, while the same complexes showed no bactericidal effect on Gram(-) bacteria. The effect of the Pd(II) and Pt(II) complexes on the in vitro DNA strand breakage was studied by agarose gel electrophoresis. The complexes 1-6 were found to exhibit a cytotoxic potency in a very low micromolar range and to be able to overcome the cisplatin resistance of A2780/Cp8 cells.

134 citations

Journal ArticleDOI
TL;DR: The cytotoxic activity shown by these compounds indicates that coupling of HFoTsc and HAcTsc to Zn(II) metal center result in metallic complexes with important biological properties since they display IC(50) values in a microM range similar to or better than that of the antitumor drug cis-platin.

112 citations

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TL;DR: In this paper, the anion of PyTsc coordinates in a planar conformation to the central palladium(II) through the pyridyl N, azomethine N and thiolato S atoms.

108 citations

Journal ArticleDOI
TL;DR: Some of these compounds increased the life span of mice bearing tumors and the effect of palladium compounds on DNA synthesis of P388 and L1210 cell cultures is reported.

104 citations


Cited by
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Journal ArticleDOI
TL;DR: A wide array of forms of palladium has been utilized as precatalysts for Heck and Suzuki coupling reactions over the last 15 years as mentioned in this paper, and there are now many suggestions in the literature that narrow the scope of types of precatalyst that may be considered true catalysts in these coupling reactions.
Abstract: A wide array of forms of palladium has been utilized as precatalysts for Heck and Suzuki coupling reactions over the last 15 years. Historically, nearly every form of palladium used has been described as the active catalytic species. However, recent research has begun to shed light on the in situ transformations that many palladium precatalysts undergo during and before the catalytic reaction, and there are now many suggestions in the literature that narrow the scope of types of palladium that may be considered true “catalysts” in these coupling reactions. In this work, for each type of precatalyst, the recent literature is summarized and the type(s) of palladium that are proposed to be truly active are enumerated. All forms of palladium, including discrete soluble palladium complexes, solid-supported metal ligand complexes, supported palladium nano- and macroparticles, soluble palladium nanoparticles, soluble ligand-free palladium, and palladium-exchanged oxides are considered and reviewed here. A considerable focus is placed on solid precatalysts and on evidence for and against catalysis by solid surfaces vs. soluble species when starting with various precatalysts. The review closes with a critical overview of various control experiments or tests that have been used by authors to assess the homogeneity or heterogeneity of catalyst systems.

1,737 citations

Journal ArticleDOI
TL;DR: An improved simple visual detection system for the results of the LAMP reaction that enables visual discrimination of results without costly specialized equipment should be helpful in basic research on medicine and pharmacy, environmental hygiene, point-of-care testing and more.
Abstract: As the human genome is decoded and its involvement in diseases is being revealed through postgenome research, increased adoption of genetic testing is expected. Critical to such testing methods is the ease of implementation and comprehensible presentation of amplification results. Loop-mediated isothermal amplification (LAMP) is a simple, rapid, specific and cost-effective nucleic acid amplification method when compared to PCR, nucleic acid sequence-based amplification, self-sustained sequence replication and strand displacement amplification. This protocol details an improved simple visual detection system for the results of the LAMP reaction. In LAMP, a large amount of DNA is synthesized, yielding a large pyrophosphate ion by-product. Pyrophosphate ion combines with divalent metallic ion to form an insoluble salt. Adding manganous ion and calcein, a fluorescent metal indicator, to the reaction solution allows a visualization of substantial alteration of the fluorescence during the one-step amplification reaction, which takes 30-60 min. As the signal recognition is highly sensitive, this system enables visual discrimination of results without costly specialized equipment. This detection method should be helpful in basic research on medicine and pharmacy, environmental hygiene, point-of-care testing and more.

1,521 citations

Journal ArticleDOI
TL;DR: This review will discuss in detail the medicinal applications of various transition metal-NHC complexes including silver, gold, rhodium, ruthenium, and palladium along with proposed mechanisms of action to suppress the bacterial growth or proliferation of tumor cells will be discussed.
Abstract: Ofele and Wanzlick reported the synthesis of the first N-heterocyclic carbene (NHC) metal complexes in 1968.1,2 The isolation of the first free carbene by Arduengo in 1991 set the scene for an ever-growing interest and advancement in the field of N-heterocyclic carbene chemistry.3 Shortly thereafter, the use of these ligands in organometallic chemistry, particularly in catalysis dramatically increased.4,5 N-heterocyclic carbenes are neutral 2-electron donors, with an ability to bond to both hard and soft metals making them more versatile ligands than phosphines.6 As an added advantage, not only are NHCs easier to synthesize and functionalize than phosphines but they also form a stronger bond to metals and therefore form more stable metal complexes than metal phosphine complexes.7,8 The N-heterocyclic carbene ligands interact with metal centers primarily through strong σ-donation and to a lesser degree through π-backdonation (Figure 1).9,10 Figure 1 Orbital diagram of NHC bonding to metal center. Ghosh and coworkers11,12,13,14,15,16 as well as others17,18,19 took special interest in the exceptional stability of several metal-NHC complexes and conducted in depth analyses in order to gain better insights into the structure and bonding. In particular, the metal-ligand donor-acceptor interactions were inspected using the charge decomposition analysis (CDA). CDA is a tool used to quantitatively estimate the degree of NHC → metal σ-donation, designated by d, and NHC ← metal π-back donation, designated by b.20,21 Thus a higher d/b ratio emphasizes the ability of NHC to function as an effective σ-donor, whereas a lower d/b ratio highlights the greater NHC ← metal π-back donation. Interestingly, in the studies conducted by Ghosh, greater NHC ← metal π-back donation was observed in Pd-NHC complexes exhibiting lower d/b ratios ranging between 2.59 – 3.9913,14 and Au-NHC complexes with d/b ratios ranging between 5.23 – 5.8815,16 as compared to the Ag-NHC complexes with d/b ratios ranging between 7.8 – 12.6811,12,16. This observation could attest to why silver-NHC complexes are particularly better transmetallating agents. The newly emerging interest in the medicinal applications of stable metal NHCs led us to examine the few accounts available in the literature dealing with this area of research. This review will discuss in detail the medicinal applications of various transition metal-NHC complexes including silver, gold, rhodium, ruthenium, and palladium. The antimicrobial, antitumor, and resistance properties, along with proposed mechanisms of action to suppress the bacterial growth or proliferation of tumor cells will be discussed.

658 citations

Journal ArticleDOI
TL;DR: This overview, collecting the most significant strategies adopted in the last ten years to design promising anticancer copper(I,II) compounds, would be a help to the researchers working in this field.
Abstract: Metal-based antitumor drugs play a relevant role in antiblastic chemotherapy. Cisplatin is regarded as one of the most effective drugs, even if severe toxicities and drug resistance phenomena limit its clinical use. Therefore, in recent years there has been a rapid expansion in research and development of novel metal-based anticancer drugs to improve clinical effectiveness, to reduce general toxicity and to broaden the spectrum of activity. The variety of metal ion functions in biology has stimulated the development of new metallodrugs other than Pt drugs with the aim to obtain compounds acting via alternative mechanisms of action. Among non-Pt compounds, copper complexes are potentially attractive as anticancer agents. Actually, since many years a lot of researches have actively investigated copper compounds based on the assumption proposal that endogenous metals may be less toxic. It has been established that the properties of copper-coordinated compounds are largely determined by the nature of ligands and donor atoms bound to the metal ion. In this review, the most remarkable achievements in the design and development of copper(I, II) complexes as antitumor agents are discussed. Special emphasis has been focused on the identification of structure-activity relationships for the different classes of copper(I,II) complexes. This work was motivated by the observation that no comprehensive surveys of copper complexes as anticancer agents were available in the literature. Moreover, up to now, despite the enormous efforts in synthesizing different classes of copper complexes, very few data concerning the molecular basis of the mechanisms underlying their antitumor activity are available. This overview, collecting the most significant strategies adopted in the last ten years to design promising anticancer copper(I,II) compounds, would be a help to the researchers working in this field.

646 citations