Download or read book Investigation of Ruthenium II Polypyridyl Dimers as Potential Chemotherapeutic Agents written by Thamara K. Janaratne and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The exploration of transition metal complexes as chemotherapeutic agents is still a relatively unexplored but promising area of research. Chapter 1 highlights the most successful anticancer drugs and potential drugs based on metal complexes, with an emphasis of platinum and ruthenium complexes. In Chapter 2, the biological activity of a series of novel ruthenium dimers is investigated with special attention given to evaluating their potential as anticancer chemotherapeutic agents. A partial list of the compound prepared includes: [Ru(bpy)(CO)2}2tpphz]4+ (74+), [Ru(bpy)(CH3CN)2}2 tpphz]4+(84+), [Ru(bpy)(C 2O4)}2tpphz] (9), [Ru(bpy)(CO)(Cl)} 2tpphz]2+ (102+), [(bpy) 2Ru(tpphz)Ru(bpy)2]4+ (11 4+), [(phen)2Ru(tpphz)Ru(phen)2] 4+ (124+), [(phen)2Ru(tatpp)Ru(phen) 2]4+ (Pp4+), [(phen) 2Ru(tatpq)Ru(phen)2]4+ (Qp 4+), [(bpy)2Ru(tatpp)Ru(bpy)2]4+ (Pb4+) and [(bpy)2Ru(tatpq)Ru(bpy) 2]4+ (Qb4+). Systematic changes in functions, such as overall charge (+4, +2, 0), the presence or absence of labile ligands, long and short bridging ligands between metal centers, and redox inactive (tpphz) and active (tatpp and tatpq) ligands allowed us to complete a structure-activity evaluation of this class of potential anticancer drugs. Most promising were the cationic dimers containing long, redox active bridging ligands, Pp4, P b4+, Qp4+ and Qb4+, which showed very high DNA binding constants (Kb = 107 to 109 M-1) and good cytotoxicity against cancer cell lines (NSCLC). Animal toxicity studies (mice) showed most cationic complexes to be acutely toxic at relatively lower doses. However, the cationic dimers containing the long tatpp or tatpq bridging ligands were well tolerated in mice with maximum tolerable doses in the range of 67-167 mg/kg for Pp 4+ and 6.7-17 mg/kg for Qp4+ as the chloride salts. These promising results led to a study of the antitumor activity of Pp4+ and Qp 4+ in vivo using a mouse melanoma model. Excitingly, complex Pp4+ seems to inhibit tumor growth in vivo although a little difference in survival times was observed. Nonetheless, the results are promising in that this was an initial screen in which numerous parameters including dosage, frequency of treatment, tumor type, etc., remains unoptimized. The ability of these complexes to damage DNA was evaluated in Chapter 3 by using a plasmid DNA assay that shows if a complex can induce single or double-strand cuts in the DNA molecule. None of the complexes causes any cleavage reactions unless an external reductant is added. However, upon addition of a common biological reductant (glutathione, dithiothritol or ascorbic acid), complex Pp4+ and Qp 4+ could be shown to induce single-strand cuts. Importantly, the DNA cleaving ability of Pp4+ is potentiated under anaerobic conditions, showing that the cleavage is not via O2 activation processes. Further studies established that complex P p4+ is doubly reduced under the assay conditions and the doubly reduced product, denoted H2Pp 4+, is the cleavage agent. As this species is oxygen sensitive and readily reoxidized to Pp4+ upon exposure to air, the [O2] 'regulates' the nuclease activity by controlling [H2Pp4+]. The ability of the ruthenium complexes to inhibit or poison topoisomerase I and II was evaluated and is reported in Chapter 4. The intercalating complexes showed the most significant topoisomerase I and II inhibition with complex Pp4+ standing out again for its potent biological activity.

Download or read book Ruthenium II Polypyridyl Complexes as Potential Anticancer Drugs written by Yanling Chen and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Research on biological activities of ruthenium polypyridyl complexes (RPCs) continues to attract interest as these complexes have shown promising anticancer activity both in vitro and in vivo.1−3 The mononuclear RPC, [(phen)2Ru(tatpp)]2+ (MP) and related dinuclear complex [(phen)2Ru(tatpp)Ru(phen)2]4+ (P) have been shown to both intercalate with DNA and shown potentiated DNA cleavage under anaerobic and reducing conditions4−5, as well as shown good selectivity and cytotoxicity towards malignant cell lines in vitro and tumors in vivo.5 Both complexes contain the redox-active tatpp ligand which is thought to be an essential component for the observed biological activities. This thesis is focused on developing improvements to the stereoselective syntheses of the chiral complexes, [delta][delta]-P and [delta]-MP. It is also investigated the synthesis of a new analogue [(phen)2Ru(tadbp)]2+ (B) and its chiral form [delta]-B which contains a modified tatpp ligand that is only capable of binding one Ru ion. Moreover this thesis explores the ability of these large complexes to traverse the cell membranes and get into cells and cell nuclei by isolating treated cells and nuclei and determining their ruthenium content by graphite furnace atomic absorption method (GFAAS). The GFAAS data show that the two examined complexes [delta][delta]-P and [delta]-MP are able to quickly penetrate into cancer cells (H-358) and concentrate in nuclei, which is postulated due to their high binding affinity to DNA.

Download or read book An Investigation of the Electronic Coupling in Some Dimeric Ruthenium II Polyridine Complexes written by Roland Ngebichie Njabon and published by . This book was released on 2013 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: A detailed understanding of respiration at the molecular level requires an understanding of the many electron transfer steps involved in the process. These electron transfer processes are extremely fast and are impossible to measure by simple rapid mixing techniques. In order to get around this problem, scientists have used laser flash photolysis. This technique relies on the fact that under proper conditions, a reactant can be generated by a very short laser pulse. Once generated, the course of the reaction can be monitored by various techniques capable of very rapid time response. Many applications of this methodology rely on the use of ruthenium (II) polypyridine complexes to initiate the reactions of interest. This approach has been used to study the rates of electron transfer between cytochrome c, and cytochrome b5, cytochrome peroxidase and cytochrome oxidase and the bc1 complex. The latter are key components in the respiration process. In these investigations special emphasis was placed on the design of ruthenium complexes that were efficient and compatible with the biological components. A thorough understanding of the design parameters are critical to continued success in this area. Dimeric ruthenium complexes at the current time appear to be among the best candidates for photochemical initiators. The photophysical properties of these complexes, however, have not yet been examined. In particular the excited-state lifetime of some of the monomers of interest appears to be comparable or even longer than the corresponding dimers. This observation is inconsistent with the single covalent bond that links the two monomeric units which would provide strong electronic coupling and rapid excited state decay. Preliminary observations suggest a very weak electronic coupling. The underlying basis of this inconsistency is important in future design endeavors and may provide useful information for the use of these complexes in other areas such as solar energy conversion. In order to investigate the magnitude of the electronic coupling, both symmetric and asymmetric ruthenium (II) dimeric complexes were synthesized. The ligands used in the synthesis of these dimers were limited to either those commercially available or those that could be easily synthesized. The symmetric ruthenium (II) bipyridine dimer ([Ru(bpy)2diphen(bpy)2](PF6)4)and ([Ru(TAP)2diphen(TAP)2](PF6)4 were synthesized through a nickel catalyzed coupling reaction . The asymmetric dimer ([Ru(bpy)2diphen(dmbpy)2](PF6)4) on the other hand was synthesized by decarbonylating [Ru(dmbpy)2(CO)2](PF6)2 with three fold of excess trimethylamine N-oxide in the presence of 2-methoxy ethanol and reacting it with [Ru(bpy)2diphen](PF6)2. Emission measurements confirmed that there is no significant difference in the excited state lifetime of the monomers and the dimers (both symmetric and asymmetric) used in this study. The result from our electrochemical studies showed that the mixed dimer complex was made up of two metal centers with different redox potentials. The symmetric dimer on the other hand has the same redox potential for each of the two metal centers and they do not interact with each other thus giving a single two electron oxidation at the same potential. Finally, our result from the emission study of the mixed dimer showed that the emission energy of the mixed dimer was equal to the average of the bpy and dmbpy dimers. From the photochemical studies, one can conclude that the mixed dimer and the symmetric dimers behaved as the monomers because there was no significant change in the excited state life time This indicates that the metal center of both the mixed dimer and the symmetric dimers are weakly coupled by the bridging ligand and there is no significant coupling between the two metal centers.

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2006 with total page 886 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Metallo Drugs Development and Action of Anticancer Agents written by Astrid Sigel and published by Walter de Gruyter GmbH & Co KG. This book was released on 2018-02-05 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 18, entitled Metallo-Drugs: Development and Action of Anticancer Agents of the series Metal Ions in Life Sciences centers on biological, medicinal inorganic chemistry. The serendipitous discovery of the antitumor activity of cis-diamminodichloroplatinum(II) (cisplatin) by Barnett Rosenberg in the 1960s is a landmark in metallodrug-based chemotherapy. The success of cisplatin in the clinic, followed by oxaliplatin and carboplatin, along with their drawbacks relating mainly to resistance development and severe toxicity, initiated research on polynuclear platinum complexes and on Pt(IV) complexes as prodrugs. Furthermore, the indicated shortcomings led to the exploration of other transition and main group metal ions, among them Ru(II/III), Au(I/III), Ti(IV), V(IV/V), and Ga(III) including also the essential metal ions Fe(II/III), Cu(I/II), and Zn(II). Ionic as well as covalent and non-covalent interactions between structurally very different complexes and biomolecules like nucleic acids, proteins, and carbohydrates are studied and discussed with regard to their possible anticancer actions. Hence, MILS-18 summarizes the research at the forefront of medicinal inorganic chemistry, including studies on the next-generation, tailor-made anticancer drugs. All this and more is treated in an authoritative and timely manner in the 17 stimulating chapters of this book, written by 39 internationally recognized experts from 10 nations (from the US via Europe to China and Australia). The impact of this vibrant research area is manifested by more than 2700 references, nearly 150 illustrations (more than half in color) and several comprehensive tables. Metallo-Drugs: Development and Action of Anticancer Agents is an essential resource for scientists working in the wide range from enzymology, material sciences, analytical, organic, and inorganic biochemistry all the way through to medicine including the clinic ... not forgetting that it also provides excellent information for teaching.

Download or read book Gold and its Complexes in Anticancer Chemotherapy written by Mohmmad Younus Wani and published by Springer Nature. This book was released on 2021-02-11 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents an overview of cancer and the genesis, and development of different treatment strategies and modalities against cancer. The emergence of gold and its complexes as promising anticancer chemotherapeutic agents have the potential to substitute or replace the platinum based chemotherapeutic agents. Gold complexes have demonstrated considerable anti-proliferative properties, chiefly attributed to their anti-mitochondrial effects, they make gold complexes excellent candidates as anti-cancer agents compared to their platinum-based counterparts. This book provides a critical review of recent advances made in the development of gold complexes as anti-cancer agents. In this context, it examines a number of different ligand architectures, provides comprehensive information on gold complexes’ mechanism of action and toxicity issues and, in closing, outlines future research directions.

Download or read book Photochemistry and Photophysics of Coordination Compounds written by Hartmut Yersin and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the Seventh International Symposium on the Photochemistry and Photophysics of Coordination Compounds Elmau/FRG, March 29-April 2, 1987

Download or read book Ruthenium Complexes written by Alvin A. Holder and published by John Wiley & Sons. This book was released on 2018-02-27 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: Edited by a team of highly respected researchers combining their expertise in chemistry, physics, and medicine, this book focuses on the use of rutheniumcontaining complexes in artificial photosynthesis and medicine. Following a brief introduction to the basic coordination chemistry of ruthenium complexes and their synthesis in section one, as well as their photophysical and photochemical properties, the authors discuss in detail the major concepts of artificial photosynthesis and mechanisms of hydrogen production and water oxidation with ruthenium in section two. The third section of the text covers biological properties and important medical applications of ruthenium complexes as therapeutic agents or in diagnostic imaging. Aimed at stimulating research in this active field, this is an invaluable information source for researchers in academia, health research institutes and governmental departments working in the field of organometallic chemistry, green and sustainable chemistry as well as medicine/drug discovery, while equally serving as a useful reference also for scientists in industry.

Download or read book Inorganic and Organometallic Transition Metal Complexes with Biological Molecules and Living Cells written by Kenneth Kam-Wing Lo and published by Academic Press. This book was released on 2016-12-30 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inorganic and Organometallic Transition Metal Complexes with Biological Molecules and Living Cells provides a complete overview of this important research area that is perfect for both newcomers and expert researchers in the field. Through concise chapters written and edited by esteemed experts, this book brings together a comprehensive treatment of the area previously only available through scattered, lengthy review articles in the literature. Advanced topics of research are covered, with particular focus on recent advances in the biological applications of transition metal complexes, including inorganic medicine, enzyme inhibitors, antiparasital agents, and biological imaging reagents. Geared toward researchers and students who seek an introductory overview of the field, as well as researchers working in advanced areas Focuses on the interactions of inorganic and organometallic transition metal complexes with biological molecules and live cells Foscuses on the fundamentals and their potential therapeutic and diagnostic applications Covers recent biological applications of transition metal complexes, such as anticancer drugs, enzyme inhibitors, bioconjugation agents, chemical biology tools, and bioimaging reagents

Download or read book Current Research in Britain written by and published by . This book was released on 1990 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chemical Aspects of Photodynamic Therapy written by Raymond Bonnett and published by CRC Press. This book was released on 2000-08-07 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photodynamic therapy (PDT) is a ground breaking medical technique which uses lasers to activate light-sensitive chemicals to treat cancer and other diseases without resorting to surgery. For the first time, Chemical Aspects of Photodynamic Therapy introduces in an accessible way the physics, chemistry and biology behind the technique. This highly a

Download or read book Inorganic Chemical Biology written by Gilles Gasser and published by John Wiley & Sons. This book was released on 2014-06-23 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding, identifying and influencing the biological systems are the primary objectives of chemical biology. From this perspective, metal complexes have always been of great assistance to chemical biologists, for example, in structural identification and purification of essential biomolecules, for visualizing cellular organelles or to inhibit specific enzymes. This inorganic side of chemical biology, which continues to receive considerable attention, is referred to as inorganic chemical biology. Inorganic Chemical Biology: Principles, Techniques and Applications provides a comprehensive overview of the current and emerging role of metal complexes in chemical biology. Throughout all of the chapters there is a strong emphasis on fundamental theoretical chemistry and experiments that have been carried out in living cells or organisms. Outlooks for the future applications of metal complexes in chemical biology are also discussed. Topics covered include: • Metal complexes as tools for structural biology • IMAC, AAS, XRF and MS as detection techniques for metals in chemical biology • Cell and organism imaging and probing DNA using metal and metal carbonyl complexes • Detection of metal ions, anions and small molecules using metal complexes • Photo-release of metal ions in living cells • Metal complexes as enzyme inhibitors and catalysts in living cells Written by a team of international experts, Inorganic Chemical Biology: Principles, Techniques and Applications is a must-have for bioinorganic, bioorganometallic and medicinal chemists as well as chemical biologists working in both academia and industry.

Download or read book Hydrogen Transfer Reactions written by Gabriela Guillena and published by Springer. This book was released on 2016-09-27 with total page 393 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Topics in Current Chemistry Collections presents critical reviews from the journal Topics in Current Chemistry organized in topical volumes. The scope of coverage is all areas of chemical science including the interfaces with related disciplines such as biology, medicine and materials science. The goal of each thematic volume is to give the non-specialist reader, whether in academia or industry, a comprehensive insight into an area where new research is emerging which is of interest to a larger scientific audience. Each review within the volume critically surveys one aspect of that topic and places it within the context of the volume as a whole. The most significant developments of the last 5 to 10 years are presented using selected examples to illustrate the principles discussed. The coverage is not intended to be an exhaustive summary of the field or include large quantities of data, but should rather be conceptual, concentrating on the methodological thinking that will allow the non-specialist reader to understand the information presented. Contributions also offer an outlook on potential future developments in the field.

Download or read book Infrared and Raman Spectra of Inorganic and Coordination Compounds Part A written by Kazuo Nakamoto and published by John Wiley & Sons. This book was released on 2008-12-22 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Sixth Edition of this classic work comprises the most comprehensive and current guide to infrared and Raman spectra of inorganic, organometallic, bioinorganic, and coordination compounds. From fundamental theories of vibrational spectroscopy to applications in a variety of compound types, this has been extensively updated. New topics include the theoretical calculations of vibrational frequencies (DFT method), chemical synthesis by matrix co-condensation reactions, time-resolved Raman spectroscopy, and more. This volume is a core reference for chemists and medical professionals working with infrared or Raman spectroscopies and an excellent textbook for graduate courses.

Download or read book Recent Advances in the Biology Therapy and Management of Melanoma written by Lester Davids and published by BoD – Books on Demand. This book was released on 2013-02-13 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book Recent Advances in the Biology, Therapy and Management of Melanoma brings up-to-date information regarding a number of aspects which culminate in illuminating potential targets in the fight against melanoma. This book is intended to be a reference book for both the scientific and clinical communities and brings complicated subject matter together in an easy, readable way. Undoubtedly fundamental scientific understanding has to then be translated to the clinic in order for us to make significant strides in eradicating melanoma. It is hoped that scientists, clinicians, students and residents find this book useful in their studies on melanoma and that it not only expands their perspectives and views on the field, but challenges them to forge ahead towards discovering the ultimate cure.

Download or read book Metal based Anticancer Agents written by Angela Casini and published by Royal Society of Chemistry. This book was released on 2019-04-05 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal-based anticancer drugs are among the most successful therapeutic agents, as evidenced by the frequent prescription of selected platinum and arsenic compounds to patients. Metal-based Anticancer Agents covers the interdisciplinary world of inorganic drug discovery and development by introducing the most prominent compound classes based on different transition metals, discussing emerging concepts and enabling methods, as well as presenting key pre-clinical and clinical aspects. Recent progress on the unique features of next-generation targeted metal-based anticancer agents, including supramolecular coordination complexes used for both therapy and drug delivery, promise a bright future beyond the benefits of pure cytotoxic activity. With contributions from global leaders in the field, this book will serve as a useful reference to established researchers as well as a practical guide to those new to metallodrugs, and postgraduate students of medicinal chemistry and metallobiology.

Download or read book Ruthenium in Organic Synthesis written by Shun-Ichi Murahashi and published by John Wiley & Sons. This book was released on 2006-03-06 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this comprehensive book, one of the leading experts, Shun-Ichi Murahashi, presents all the important facets of modern synthetic chemistry using Ruthenium, ranging from hydrogenation to metathesis. In 14 contributions, written by an international authorship, readers will find all the information they need about this fascinating and extraordinary chemistry. The result is a high quality information source and a indispensable reading for everyone working in organometallic chemistry. From the contents: Introduction (S.-I. Murahashi) Hydrogenation and Transfer Hydrogenation (M. Kitamura and R. Noyori) Oxidations (S.-I. Murahashi and N. Komiya) Carbon-Carbon Bond Formations via Ruthenacycle Intermediates (K. Itoh) Carbon-Carbon Bond Formation via pi-Allylruthenium Intermediates (T. Mitsudo) Olefin Metathesis (R. H. Grubbs) Cyclopropanation (H. Nishiyama) Nucleophilic Addition to Alkynes and Reactions via Vinylidene Intermediates (P. Dixneuf) Reactions via C-H Activation (N. Chatani) Lewis Acid Reactions (E. P. Kundig) Reactions with CO and CO2 (T. Mitsudo) Isomerization of Organic Substrates Catalyzed by Ruthenium Complexes (H. Suzuki) Radical Reactions (H. Nagashima) Bond Cleavage Reactions (S. Komiya)