Saponins are glycosides of triterpenes, steroids or steroidal alkaloids. They can be found in plants and marine organisms. Very diverse biological activities are ascribed to saponins and they play important roles in food, animal feedstuffs, and pharmaceutical properties. This volume provides a selection of recent work on saponins presented at a symposium in Pulawy, Poland, in 1999. Many different aspects are treated: analysis, separation, biological activities, relevant use in human and animal nutrition, and ecological significance. This book will be of use to researchers both in universities and industry.

This thesis targets molecular or organic spintronics and more particularly the spin polarization tailoring opportunities that arise from the ferromagnetic metal/molecule hybridization at interfaces: the new concept of spinterface. Molecular or organic spintronics is an emerging research field at the frontier between organic chemistry and spintronics. The manuscript is divided into three parts, the first of which introduces the basic concepts of spintronics and advantages that molecules can bring to this field. The state of the art on organic and molecular spintronics is also presented, with a special emphasis on the physics and experimental evidence for spinterfaces. The book's second and third parts are dedicated to the two main experimental topics investigated in the thesis: Self-Assembled Monolayers (SAMs) and Organic Semiconductors (OSCs). The study of SAMs-based magnetic tunnel nanojunctions reveals the potential to modulate the properties of such devices "at will," since each part of the molecule can be tuned independently like a "LEGO" building block. The study of Alq3-based spin valves reveals magnetoresistance effects at room temperature and is aimed at understanding the respective roles played by the two interfaces. Through the development of these systems, we demonstrate their potential for spintronics and provide a solid foundation for spin polarization engineering at the molecular level.

Species are not functionally independent. From a long-term perspective, only ecosystem with a fully integrated nutrient cycle is alive. The lack of trophic autonomy should be considered one of the key factors that ensure and maintain biodiversity. The variability of abiotic conditions, both in space and in time, also creates a huge diversity of niches and subniches for genotypes and species. In addition, life maintains its essential variables (biomass and productivity) as stable as possible due to the diversity of structures (genes, macromolecules, metabolic pathways, genotypes, species, etc.): the structures that reach optima are multiplied and thus activated, while the functioning of those which lost their optima is suppressed. The facts and concepts presented in this monograph thus support the conclusions that (a) genotype and species diversity is supported by trophic specialisation (b) biodiversity helps to stabilise the functions (essential variables) of individuals, populations, and ecological communities (c) in evolution, the emergence of biodiversity is determined by heritable variation and the advantage of specialised (more effective) structures over non-specialised ones (d) biodiversity is characterised by its ability to increase itself and to organise itself into relatively consistent structures, which we call production pyramids and nutrient cycles. This book therefore provides an answer to the question "why the diversity of life is of such and such a nature".

This comprehensive and unique text presents a full overview of downstream processing useful for those new to the concept as well as professionals with experience in the area. The history and theoretical principles of Aqueous Two-Phase Systems (ATPS) are covered in depth. Information on ATPS characterization and application is included, and ATPS equilibria and system parameters that have significant effect on partition behavior are studied. Aqueous Two-Phase Systems for Bioprocess Development for the Recovery of Biological Products addresses specific applications of ATPS for the recovery and partial purification of high molecular weight compounds such as proteins, nucleic acids and polysaccharides, particulate bioproducts such as cells and organelles and low molecular weight compounds. Non-conventional strategies involving ATPS such as affinity systems, continuous liquid-liquid fractionation stages and the recovery from plant extracts are presented. Economic analysis of the application of ATPS in comparison to other fractionation techniques, particularly liquid chromatography, is considered, as are opportunity and current trends in the ATPS research area. Each chapter utilizes the contributors' experimental expertise in traditional and non-conventional ATPS strategies, as well as analysis of areas of opportunity and perspectives on the development and future applications of ATPS in both the lab and larger scale operations. The result is a thorough and singular overview of ATPS which has not been matched by any other text on the market.

The volumes of this classic series, now referred to simply as "Zechmeister" after its founder, L. Zechmeister, have appeared under the Springer Imprint ever since the series' inauguration in 1938. The volumes contain contributions on various topics related to the origin, distribution, chemistry, synthesis, biochemistry, function or use of various classes of naturally occurring substances ranging from small molecules to biopolymers. Each contribution is written by a recognized authority in his field and provides a comprehensive and up-to-date review of the topic in question. Addressed to biologists, technologists, and chemists alike, the series can be used by the expert as a source of information and literature citations and by the non-expert as a means of orientation in a rapidly developing discipline.

This book highlights key advances that have occurred in the field of olefin conversion in recent years. The role of homogenous transition metal catalysts which contain an imine functionality is emphasized; their potential applications in the processing and upgrade of olefins to a wide variety of commodity products of very high industrial value is also explored. On the threshold of the fiftieth anniversary of the Noble Prize to Ziegler and Natta, this book gives a critical summary of the state of the art developments in the fascinating and rapidly developing field of the olefin polymerization, oligomerization, and co-polymerization catalysis.

This book should be of interest to organic and biological chemists in universities, professional research chemists in pharmaceutical and dye industries.

Natural gums are polysaccharides consisting of multiple sugar units linked together via glycosidic linkages. Most natural gums reveal appropriate safety for oral consumption in the form of food additives or drug carriers. Challenges related to the utilization of natural polysaccharides, however, include uncontrolled rates of hydration, pH dependent solubility, viscosity reduction during storage, and weak interfacial properties. Modification provides an efficient route for not only removing such drawbacks but also improving physicochemical properties, such as solubility, viscosity and swelling index, and introducing new properties for varied applications.This book provides a comprehensive review of the various modifications on gums to make them suitable for food, cosmetic and pharmaceutical industries. The book is divided in four parts: an introduction to natural gums followed by in-depth coverage of chemical modification, physical modification, and enzymatic modification of gums. Each chapter includes reaction mechanisms, physicochemical properties, rheological properties, interfacial properties, applications and future perspectives. Presenting a succinct account on gum modification from a practical point of view, this book is a helpful reference for academic and industrial scientists and engineers in food technology, materials chemistry, pharmaceuticals, chemical, industrial, and applied engineering, biochemistry, and biopolymers.

One of the most active areas of contemporary organic chemistry involves the search for new catalysts that borrow concepts, strategies and even components from enzymes but yet are not found in nature. Such artificial enzymes not only give enormous insights into the mechanisms of enzyme catalysis but also offer the potential for catalyzing a wide range of chemical reactions with no counterpart in nature. Several approaches have been taken in the deVelopment of new catalysts, some based on biological methods and others on synthetic techniques. Site directed mutagenesis has allowed the direct replacement of amino acids in an enzyme with resulting changes in stability, selectivity and mechanism. Recent developments have shown that even non-natural amino acids can be incorporated into proteins and also that enzymes can function effectively in organic solvents. A different biological route to artificial enzymes has exploited the immune system and its ability to generate millions of antibodies to a given antigen. Novel antigens have been designed to mimic the transition states of chemical reactions. Antibodies elicited against these antigens thus contain an active site that is complementary to transition state structure and can potentially catalyze target reactions. A broad range of reactions can now be 6 catalyzed using the method with rate accelerations reaching 10 compared to the control reactions. Protein engineering and catalytic antibodies represent complex solutions to the problem of artificial enzymes. Their complexity is however their principal limitation.

This book focuses on chemical reactions and processing under extreme conditions-how materials react with highly concentrated active species and/or in a very confined high-temperature and high-pressure volume. Those ultimate reaction environments created by a focused laser beam, discharges, ion bombardments, or microwaves provide characteristic nano- and submicron-sized products and functional nanostructures. The book explores the chemistry and processing of metals and non-metals as well as molecules that are strongly dependent on the energy deposition processes and character of the materials. Descriptions of a wide range of topics are given from the perspective of a variety of research methodologies, material preparations, and applications. The reader is led to consider and review how a high-energy source interacts with materials, and what the key factors are that determine the quality and quantity of nanoproducts and nano-processing.

Combinatorial chemistry and molecular diversity approaches to scientific and novel product R & D have exploded in the 1990s. For example, in the preparation of drug candidates, the automated, permutational, and combinatorial use of chemical building blocks now allows the generation and screening of unprecedented numbers of compounds. Drug discovery - better, faster, cheaper? Indeed more compounds have been made and screened in the 1990s than in the last hundred years of pharmaceutical research. The second volume in this series includes contributions on methods, solid phases, purification, analysis, carbohydrates, patent strategies and tactics, diversity profiling and combinatorial series design, and finishes with a survey of chemical libraries yielding biologically active agents and a compendium of solid phase chemistry publications. Each contribution is prepared by a recognized expert resulting in a high quality account of the recent advances in the field.

This collection explores state-of-the-art methods and protocols for research on photodynamic therapy (PDT) and its use in a wide range of medical applications, from antiviral to anticancer. Beginning with an extensive section on in vitro and in vivo models, the volume continues with chapters on oxygen-independent photosensitizers, next-generation photosensitization strategies, contemporary insights into the immunomodulatory effects of PDT, antimicrobial effects of PDT, as well as a variety of general biochemical and molecular biological techniques. Written for the highly successful Methods in Molecular Biology series, chapters include the kind of detailed implementation advice that ensures successful results in the lab. Thorough and authoritative, Photodynamic Therapy: Methods and Protocols serves as an ideal source of inspiration for both new and established PDT scientists and a guide for designing innovative research programs in this continuously advancing and multidisciplinary field.

Combinatorial chemistry and molecular diversity approaches to scientific inquiry and novel product R&D have exploded in the 1990s! For example, in the preparation of drug candidates, the automated, permutational, and combinatorial use of chemical building blocks now allows the generation and screening of unprecedented numbers of compounds. Drug discovery - better, faster, cheaper? Indeed, more compounds have been made and screened in the 1990s than in the last hundred years of pharmaceutical research. This first volume covers: (i) combinatorial chemistry, (ii) combinatorial biology and evolution, and (iii) informatics and related topics. Within each section chapters are prepared by experts in the field, including, for example, in Section I: Coverage of mixture pools vs. parallel individual compound synthesis, solution vs. solid-phase synthesis, analytical tools, and automation. Section II highlights selection strategies and library-based evolution, phage display, peptide and nucleic acid libraries. Section III covers databases and library design, high through-put screening, coding strategies vs. deconvolutions, intellectual property issues, deals and collaborations, and successes to date.

This collection addresses new research and technology for increased efficiency, energy reduction, and waste minimization in mineral processing, extractive metallurgy, and recycling. Professor Patrick R. Taylor and his students have been studying these topics for the past 45 years. Chapters include new directions in:* Mineral Processing * Hydrometallurgy * Pyrometallurgy * Electrometallurgy * Metals and E waste recycling * Waste minimization (including by-product recovery) * Innovations in metallurgical engineering education and curriculum development

This volume contains the proceedings of the Ninth International Symposium on Cyclodextrins, held in Santiago de Compostela, Spain, May 31 - June 3, 1998. The papers collected represent a summary of the last two years' achievements in the application of cyclodextrins in such diverse fields as pharmaceuticals, biotechnology, textiles, chromatography and environmental sciences. Highlights: Chiral selection of chemicals, nuclear waste management, cyclodextrins in nasal drug delivery, cyclodextrins in pulmonary drug delivery, cyclodextrins as pharmaceutical excipients, pharmacokinetics, stabilization of drugs by cyclodextrins, structural characterization of cyclodextrin complexes by nuclear magnetic resonance and molecular modeling, artificial receptors, large cyclodextrins, cyclodextrins as enzyme models, new cyclodextrin derivatives and potentials. Audience: This book will be of interest to researchers whose work involves biotechnology, pharmaceuticals, food and chemicals and chromatographic methods, as well as fundamental cyclodextrin research.

Organic Chemistry I For Dummies, 2nd Edition (9781119293378) was previously published as Organic Chemistry I For Dummies, 2nd Edition (9781118828076). While this version features a new Dummies cover and design, the content is the same as the prior release and should not be considered a new or updated product. The easy way to take the confusion out of organic chemistry Organic chemistry has a long-standing reputation as a difficult course. Organic Chemistry I For Dummies takes a simple approach to the topic, allowing you to grasp concepts at your own pace. This fun, easy-to-understand guide explains the basic principles of organic chemistry in simple terms, providing insight into the language of organic chemists, the major classes of compounds, and top trouble spots. You'll also get the nuts and bolts of tackling organic chemistry problems, from knowing where to start to spotting sneaky tricks that professors like to incorporate. Refreshed example equations New explanations and practical examples that reflect today's teaching methods Fully worked-out organic chemistry problems Baffled by benzines? Confused by carboxylic acids? Here's the help you need--in plain English!

The importance of molecular recognition in chemistry and biology is reflected in a recent upsurge in relevant research, promoted in particular by high-profile initiatives in this area in Europe, the USA and Japan. Although molecular recognition is necessarily microscopic in origin, its consequences are de facto macroscopic. Accordingly, a text that starts with intermolecular interactions between simple molecules and builds to a discussion of molecular recognition involving larger scale systems is timely. This book was planned with such a development in mind. The book begins with an elementary but rigorous account of the various types of forces between molecules. Chapter 2 is concerned with the hydrogen bond between pairs of simple molecules in the gas phase, with particular reference to the preferred relative orientation of the pair and the ease with which this can be distorted. This microscopic view continues in chapter 3 wherein the nature of interactions between solute molecules and solvents or between two or more solutes is examined from the experimental standpoint, with various types of spectroscopy providing the probe of the nature of the interactions. Molecular recognition is central to the catalysis of chemical reactions, especially when bonds are to be broken and formed under the severe con straint that a specific configuration is to result, as in the production of enan tiotopically pure compounds. This important topic is considered in chapter 4.

The volumes 3/I and 3/J present a modern account of polycyclic aromatic hydrocarbons (PAHs) and their heterocyclic analogs in the environment. The authors are internationally well recognized scientists belonging to those working presently in the frontline of the different subfields of this interdisciplinary area of environmental science; they give an integrated thorough overview on this hot topic. Extensive cross-referencing between chapters provides the readers with an easy access to all major areas. Due to the huge amount of material the text is published in two volumes (3/I and 3/J). It is expected that both volumes will soon become a major source of information and inspiration for all researchers actively working in PAH environmental chemistry or ecology.

The first review describes examples of very promising compounds discovered from plants acquired from Africa, Southeast Asia, the Americas, and the Caribbean region with potential anticancer activity. These include plant secondary metabolites of the diphyllin lignan, penta[b]benzofuran, triterpenoid, and tropane alkaloid types. The second review presents 40 more erythrinan alkaloids, which were either new or were missed out in the last major reviews, bringing to a total of 154 known erythrinan alkaloids known to date. The reported pharmacological activities of the new and known alkaloids showed a greater bias towards central nervous system and related activities. Other prominent activities reported were antifeedant or insecticidal, cytotoxicity/anti tumor/anti cancer/estrogenic, antiprotozoal, antiinflammatory, antioxidant, antifungal and antiviral activities.

The unique properties and applications of transition metal compounds have long fascinated both physicists and chemists. This volume presents theoretical and experimental studies for a deeper understanding of the electronic and vibronic properties of these compounds. In particular, an introduction into properties of spin sublevels of dd*, dA*, and AA* states is given, and a modern ligand field theory based on the Angular Overlap Model is presented. In experimental case studies it is shown how to characterize different types of electronic transitions using modern methods of laser spectroscopy. Consequences of spin-orbit coupling, zero-field splittings, spin-lattice relaxations, chromophore-matrix interactions, Herzberg-Teller/Franck-Condon activities, and localization/delocalization properties are treated.

Nanoparticles in Green Organic Synthesis: Strategy towards Sustainability presents the fundamental and latest practical uses of metal nanoparticles (MNPs) in organic synthesis, as well as their promising multidimensional applications. The book examines the latest emerging research on MNP synthesis and their applications-from organic transformation to energy and the environment-allowing readers to critically analyze the role of different MNPs in seeking ideas for widespread application. The book covers the fundamentals while also providing a comprehensive account of MNPs and their modification for a variety of green platform-based derivatives, focusing on the multifunctional technological evolution. The book covers a wide range of applications in organic synthesis using a variety of transition-metal-based nanoparticles in both homo- and heterogeneous media. The text details the concept of catalyst design and recent developments in the preparation and characterization of nanomaterials, followed by several chapters on the design of catalysts for specific applications. This volume is a valuable resource for those working in green chemistry, sustainability, material science and engineering, nanotechnology, energy, and the environment.

Organocatalysis is considered today one of the three pillars in asymmetric catalysis, along with biocatalysis and organometallic catalysis. The possibility to combine organocatalysis with radical chemistry, photocatalysis and enabling technologies opened new avenues in organic synthesis.

Poly mer Interface and Adhesion provides the critical basis for further advancement in thisfield. Combining the principles of interfacial science, rheology, stress analysis, and fracturemechanics, the book teaches a new approach to the analysis of long standing problemssuch as: how is the interface formed; what are its physical and mechanical properties;and how does the interface modify the stress field and fracture strength of the material.The book offers many outstanding features, including extensive listings of pertinent references,exhaustive tabulations of the interfacial properties of polymers, critical reviews ofthe many conflicting theories, and complete discussions of coupling agents, adhesion promotion,and surface modifications. Emphasis is placed on physical concepts and mechanisms,using clear, understandable mathematics.Polymer Interface and Adhesion promotes a more thorough understanding of the physical,mechanical, and adhesive properties of multiphase, polymer systems. Polymer scientistsand engineers, surface chemists, materials scientists, rheologists, as well as chemical andmechanical engineers interested in the research, development or industrial applications ofpolymers, plastics, fibers, coatings, adhesives, and composites need this important newsource book.

This book promotes a basic understanding of the concept of solubility and miscibility between halogenated hydrocarbons and water. It points out the regularities existing between solubility and physical properties of solute and solvent. The book is valuable to chemists and chemical engineers.