bluuebunny/crossref_metadata_2025 huggingface dataset:
Atomic weights of the elements 1999 (IUPAC Technical Report)
Authors: Coplen Tyler B.
Published: October 2007

The biennial review of atomic-weight, A
r(E), determinations and other cognate data have resulted in changes for the standard atomic weights of the following elements:

element

From
To

nitrogen

14.006 74 ± 0.000 07
14.0067 ± 0.0002

sulfur

32.066 ± 0.006
32.065 ± 0.005

chlorine

35.4527 ± 0.0009
35.453 ± 0.002

germanium

72.61 ± 0.02
72.64 ± 0.01

xenon

131.29 ± 0.02
131.293 ± 0.006

erbium

167.26 ± 0.03
167.259 ± 0.003

uranium

238.0289 ± 0.0001
238.028 91 ± 0.000 03

Presented are updated tables of the standard atomic weights and their uncertainties estimated by combining experimental uncertainties and terrestrial variabilities. In addition, this report again contains an updated table of relative atomic-mass values and half-lives of selected radioisotopes. Changes in the evaluated isotopic abundance values from those published in 1997 are so minor that an updated list will not be published for the year 1999.

Many elements have a different isotopic composition in some nonterrestrial materials. Some recent data on parent nuclides that might affect isotopic abundances or atomic-weight values are included in this report for the information of the interested scientific community.
Lexicon of lipid nutrition (IUPAC Technical Report)
Authors: Beare-Rogers J. L. , Dieffenbacher A. , Holm J. V.
Published: October 2007

The intertwining of lipid nutrition with many other disciplines makes contributions from different directions imperative. Chemistry, biochemistry, physiology, food science and technology, industrial processing, and consumer acceptance provide concepts and terms used in lipid nutrition. This document is the product of a working group comprising members of the Committee on the Biological Role of Fatty Acids in Human Nutrition of the International Union of Nutritional Sciences and of the Commission on Oils, Fats, and Derivatives of the International Union of Pure and Applied Chemistry. Shorthand formulas and systematic and trivial names of some biologically important fatty acids are given in Table 1 (saturated fatty acids), Table 2 (monoenoic fatty acids), and Table 3 (polyenoic fatty acids).

Fatty acid compositions of foods have been based on the data of the USDA reference that means official grade standards for agriculture of the U.S. Department of Agriculture. Because foods may show large variations in their composition the figures in the annexed tables serve as guidelines only, except those of the Codex alimentarius (Tables 4 and 5), where accepted ranges of the figures are reported. Further, as these standards are in constant revision the reader may contact directly the USDA Agriculture Marketing Service for the last editions of these standards.

It is evident that the explanation of the referred terms is a compromise between technological and scientific correctness and the readers' lack of interest in many of the details. But, sometimes a more exhaustive explanation is necessary. Further information then may be found in cross references, although they have been reduced to those of utmost necessity. Terms in the text where cross references are available are printed in boldfaced type.

As research and science are progressing and knowledge is increasing, consequently, views on certain nutritional aspects are constantly changing, e.g., the role of essential fatty acids in human nutrition. Therefore, such a work will never be complete, and readers are invited to send their comments and observations to the authors for incorporation into a next edition.
Measurement and analysis of results obtained on biological substances with differential scanning calorimetry (IUPAC Technical Report)
Authors: Hinz Hans-Jürgen , Schwarz Frederick P.
Published: October 2007

Differential scanning calorimeters (DSCs) have been widely used to determine the thermodynamics of phase transitions and conformational changes in biological systems including proteins, nucleic acid sequences, and lipid assemblies. DSCs monitor the temperature difference between two vessels, one containing the biological solution and the other containing a reference solution, as a function of temperature at a given scan rate. Recommendations for DSC measurement procedures, calibration procedures, and procedures for testing the performance of the DSC are described. Analysis of the measurements should include a correction for the time response of the instrument and conversion of the power vs. time curve to a heat capacity vs. temperature plot. Thermodynamic transition models should only be applied to the analysis of the heat capacity curves if the model-derived transition temperatures and enthalpies are independent of the DSC scan rate. Otherwise, kinetic models should be applied to the analysis of the data. Application of thermodynamic transition models involving two states, two states and dissociation, and three states to the heat capacity vs. temperature data are described. To check the operating performance with standard DSCs, samples of 1 to 10 mg mL­1 solutions of hen egg white lysozyme in 0.1 M HCl-glycine buffer at pH = 2.4 ± 0.1 were sent to six different DSC laboratories worldwide. The values obtained from proper measurements and application of a two-state transition model yielded an average unfolding transition temperature for lysozyme of 331.2 K with values ranging from 329.4 to 331.9 K, and an average transition enthalpy of 405 kJ mol­1 with values ranging from 377 to 439 kJ mol­1. It is recommended that the reporting of DSC results be specific with regard to the composition of the solution, the operating conditions and calibrations of the DSC, determination of base lines that may be model-dependent, and the model used in the analysis of the data.
Reliable solubility data in the age of computerized chemistry. Why, how, and when?
Authors: Rumble John , Lee Angela Y. , Blakeslee Dorothy , Young Shari
Published: October 2007

Since 1979, the International Union of Pure and Applied Chemistry (IUPAC) Commission V.8 on Solubility Data has published over 70 compilations of evaluated data on the solubility of gases in liquids, liquids in liquids, and solids in liquids. These volumes represent one of the largest collections of chemical property data ever produced and are the result of work of scientists throughout the world. In 1998, IUPAC signed an agreement with the National Institute of Standards and Technology (NIST) to continue the series by replacing the monographs by articles in the Journal of Physical and Chemical Reference Data. Five data compilations have already been published in the Journal, and many more are under way. Recently, IUPAC and NIST have concluded another agreement about computerizing all previously published IUPAC solubility data. In this paper, we describe in detail the computerization of IUPAC solubility data, with some emphasis on harmonizing data published over a long time period. We describe the anticipated query paths that will be supported. We also discuss some of the driving forces for making these and other data resources available over the World Wide Web.
Solubility equilibria in multicomponent oceanic salt systems from t = 0 to 200 °C. Model parameterization and databases
Authors: Voigt W.
Published: October 2007

In this paper the application of Pitzer's equations for modeling of solubility equilibria in the hexary oceanic salt system Na+, K+, Mg2+, Ca2+ // Cl­, SO4
2­­H2 O and its subsystems over large temperature intervals is discussed. Lack of ternary solution data considerably restricts the use of the equations as an evaluation tool for the quality of solubility data. Models optimized for the available data in two temperature intervals have been derived. Since Pitzer's model gives no guidance for temperature dependence, the number of parameters is dominated by temperature coefficients. Thus, for extended temperature intervals other approaches like the Cohen-Adad formalism can be advantageous in solubility data evaluation.
Definitions of basic terms relating to low-molar-mass and polymer liquid crystals (IUPAC Recommendations 2001)
Authors: Barón Máximo
Published: October 2007

This document is the first published by the IUPAC Commission on Macromolecular Nomenclature dealing specifically with liquid crystals. Because of the breadth of its scope, it has been prepared in collaboration with representatives of the International Liquid Crystal Society.

The document gives definitions of terms related to low-molar-mass and polymer liquid crystals. It relies on basic definitions of terms that are widely used in the field of liquid crystals and in polymer science. The terms are arranged in five sections dealing with general definitions of liquid-crystalline and mesomorphic states of matter, types of mesophases, optical textures and defects of liquid crystals, the physical characteristics of liquid crystals (including electro-optical and magneto-optical properties), and finally liquid-crystal polymers. The terms that have been selected are those most commonly encountered in the conventional structural, thermal, and electro-optical characterization of liquid-crystalline materials.
Unit "katal" for catalytic activity (IUPAC Technical Report)
Authors: Dybkær René
Published: October 2007

Expressing the amount of a catalyst is often most conveniently done by assessing its catalytic effect. Under zero-order kinetics the catalyzed rate of conversion for a specified reaction is constant and proportionate to the amount-of-substance concentration of catalyst present. Defining the kind-of-quantity "catalytic activity" as a property of the catalyst measured by the catalyzed rate of conversion, the coherent SI unit is mole per second. Following thorough discussions in the IUPAC, the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC), the International Union of Biochemistry and Molecular Biology (IUBMB), and the World Health Organization (WHO), a petition was presented by the IFCC to the International Committee for Weights and Measures (CIPM) on a special name "katal", symbol kat, for "mole per second" when used in measuring catalytic activity. This request was granted by the General Conference for Weights and Measures (CGPM) by Resolution 12 (1999). Hereafter, the coherent SI unit katal = 1 mol s­1 should replace the off-system IUB unit "(enzyme) unit" = 1 mmol min­1 16.67 nkat. Thus, by suitable definition of reaction conditions, results for catalytic activity and derivative kinds-of-quantity are metrologically traceable to the SI.
Part B. Retention parameters in gas chromatograpy
Authors: Domínguez José Antonio García , Díez-Masa José Carlos
Published: October 2007

The paper presents a revision of terms in the IUPAC "Nomenclature for Chromatography", Pure and Applied Chemistry, 65, 819-872, 1993. The terms revised pertain to hold-up volumes in gas, liquid, and supercritical-fluid chromatography, as well as to basic retention parameters, especially in gas chromatography. A number of related and derived definitions are described, including definitions of the terms "chromatographic process" and "chromatographic phase system". A number of the original terms were found to be misleading or superfluous, including such terms as corrected retention time, net retention time, total retention volume (time), and specific retention volume at 0 °C, and their use is strongly discouraged

In Part A, the concept of the hold-up volume in chromatography is discussed. The paper also compares methods described in the literature to determine the hold-up volume.

In Part B, retention parameters in gas chromatography are discussed with the aim of (i) emphasizing the physical meaning of the terms and (ii) specifying the temperatures and pressures for the terms for gas volumes and flow rates.

The appendix presents revised recommendations for the terminology of some items, as well as those that are not recommended.
Risk assessment for occupational exposure to chemicals. A review of current methodology (IUPAC Technical Report)
Authors: Herber Robert F. M. , Duffus John H. , Christensen Jytte Molin , Olsen Erik , Park Milton V.
Published: October 2007

This paper reviews the methodology available for risk assessment of exposure to substances in the workplace. Assessment starts with the identification and classification of hazard, which must be related to the dose­effect and dose­response information available for the hazards identified. Once the potential for exposure has been characterized, it should be quantified and compared with an established safe exposure level. The degree to which it exceeds that level is a measure of the risk. Even if the assessed risk is regarded as acceptable, there is the possibility that the situation will change with time, so it is important to monitor potentially harmful exposures. Factors relevant to effective monitoring are reviewed. Addresses of Internet sites where further information may be obtained are listed along with further reading.
Integrating natural product synthesis and combinatorial chemistry
Authors: Ganesan A.
Published: October 2007

The fields of natural product total synthesis and combinatorial chemistry have major differences as well as much in common. Unique to combinatorial chemistry is the need to devise rapid and efficient methods for parallel synthesis and purification, while an area of overlap is the targeting of natural product scaffolds for combinatorial libraries. Both these aspects are illustrated with examples from our research.
Recent applications of tricarbonyliron-diene complexes to organic synthesis
Authors: Knölker Hans-Joachim , Braier Arnold , Bröcher Dirk J. , Cämmerer Simon , Fröhner Wolfgang , Gonser Peter , Hermann Holger , Herzberg Daniela , Reddy Kethiri R. , Rohde Guy
Published: October 2007

The present review describes some of our recent applications of tricarbonyliron-diene chemistry to organic synthesis. It focuses on the selective synthesis of tricarbonyliron-diene complexes including the asymmetric catalytic complexation of prochiral cyclohexa-1,3-dienes, the enantioselective synthesis of carbazole-3,4-quinone alkaloids, and the iron-mediated synthesis of corannulene and yohimbane alkaloids.
New methods for high-throughput synthesis
Authors: Kobayashi Shū , Akiyama Ryo
Published: October 2007

New methodologies for library synthesis have been developed. They are based on new carbon­carbon bond-formation reactions in the solid-phase and organic synthesis using polymer-supported catalysts. We have immobilized alkyl glyoxylate equivalents onto resins and prepared novel polymer-supported imines. We have also developed unprecedented polymer-supported catalysts such as microencapsulated scandium trifluoromethanesulfonate [MC Sc(OTf)3], osmium tetroxide (MC OsO4), and palladium triphenylphosphine [MC Pd(PPh3)] for high-throughput synthesis.
Strategy for globalization of chemical education based on the Internet
Authors: Takeuchi Yoshito , Ito Masato M. , Yoshida Hiroshi
Published: October 2007

It is likely that in the age of globalization, chemical education cannot be unaffected by this trend. The essential prerequisite for globalization would be a common curriculum. It has long been assumed that a common curriculum is technically impossible because of the difficulty involved in the dissemination of information. There is now a realistic possibility that this difficulty will be substantially reduced, if not eliminated, by use of the Internet. Difficulties involved in the translation of text will also be reduced by the use of accurate and low-cost translation software. Under such circumstances, what is urgently needed is the establishment of teaching materials translation centers around the world.
Crystalline inclusion complexes as media of molecular recognitions and selective reactions
Authors: Toda Fumio
Published: October 2007

Hexaol host compounds which include guest molecules maximum in 1:6 ratio were prepared. Aromatic hexaol host, hexahydroxytriphenylene, was found to form chiral inclusion crystal by complexation with achiral guest molecules. Some interesting and important optical resolutions of rac-guests by inclusion complexation with a chiral host were described. When chemical reaction and the inclusion complexation procedures in a water suspension medium are combined, new economical and ecological method of the preparation of optically active compound can be established. When photochemical reactions are carried out in an inclusion crystal with a chiral host, enantioselective reactions occur, and optically active product can be obtained. Several successful reactions are described.
Isolation, identification, synthesis, and bioefficacy of female Diacrisia obliqua (Arctiidae) sex pheromone blend. An Indian agricultural pest
Authors: Yadav J. S. , Valli M. Y. , Prasad A. R.
Published: October 2007

Diacrisia obliqua is a polyphagous pest especially on oil seed crops. Adult female sex pheromone blend consists of five pheromone components, which include (3Z,6Z)-cis-9,10-epoxyl,3,6-henicosatriene and (3Z,6Z)-cis-9,10-epoxy3,6-henicosadiene. Synthesis of these enantiomers was achieved through alkylative epoxide rearrangement and stereoselective Wittig olefination reactions as key steps. Bioefficacy experiments both at laboratory and minifield were very positive.
Bioremediation. An overview
Authors: Vidali M.
Published: October 2007

A brief outline of the development of bioremediation technologies is presented. The major features and limitations are discussed, and an overview of the current state of the art in field applications is sketched.
Recent results from natural product research at the University of Botswana
Authors: Majinda Runner R. T. , Abegaz Berhanu M. , Bezabih Merhatibeb , Ngadjui Bonaventure T. , Wanjala Cornelius C. W. , Mdee Ladislaus K. , Bojase Gomotsang , Silayo Alfonse , Masesane Ishmael , Yeboah Samuel O.
Published: October 2007

Marketed plants are very important items of trade in many parts of the world. The community uses these for a variety of purposes such as foods, cosmetics, flavors, spices, and medicines. It seems that plants that are used for medicinal purposes form the most common category. Four plants used for treatment of microbial infections, viz., Bolusanthus speciosus, Erythrina latissima, Crotalaria podocarpa, and Elephantorrhiza goetzei, were investigated, and these yielded several known and novel structures, some with appreciable antibiotic activity against the test organisms. The activity of some of the isolated plants and the parts of the plant from which these were obtained lend support to their traditional use. Bulbine abyssinica and B. capitata yielded phenylanthraquinones, some of which were shown to possess strong antiplasmodial activity. In addition, these yielded isofuranonaphthoquinones, which were also found to be weakly antiplasmodial and antioxidant. Scilla nervosa yielded several known and novel homoisoflavoinds of the 3-benzylchroman-4-ones and 3-benzylidinechroman-4-one type, as well as some stilbenoids. The homoisoflavonoids showed strong antitumor activity against various cancer cell lines. Rhus pyroides gave a novel bichalcone, which showed weak antifeedant activity, consistent with the observation by farmers that the plant was avoided by corn cricket. Results from investigated Dorstenia species originating from Cameroon, Ethiopia, and Tanzania yielded styrenes, coumarins, chalcones, and flavonoids. The chalcones and flavonoids showed various levels of prenylation or geranylation, and an observation made so far is that prenylated flavonoids are only found in Dorstenia species of African origin. The only example of a bis-geranylated chalcone is found in Dorstenia.
Teaching chemistry from a societal perspective
Authors: Ware Sylvia A.
Published: October 2007

Chemistry and chemical technology contribute to the quality of life on this planet in many areas: health, nutrition, agriculture, transportation, materials and energy production, and industrial development. Chemistry is at its most useful to society when chemists and non-chemists with decision-making responsibilities work with mutual understanding to address the chemistry-related issues facing their communities. Thus, it would seem obvious that all who study chemistry should learn about the interactions of chemistry and society as an integral part of their classroom instruction. However, historically, the tendency worldwide has been to include societal content in chemistry courses only at the lower secondary level. This is changing. This paper explores instructional materials developed by the American Chemical Society that place chemistry in its societal context for high school and college students. This includes a discussion of green chemistry materials that introduce students to the concepts associated with developing environmentally benign processes and products.
American Chemical Society assistance to chemical scientists and engineers in developing countries
Authors: Malin John M.
Published: October 2007

The American Chemical Society, through its Office of International Activities, is engaged in a variety of activities to assist chemical scientists and engineers in developing countries. These include surveys of chemical activity in Latin America and Africa; assistance to sister chemical societies; organization of international exchange programs; production of environmental chemistry workshops; hosting invited visitors at PITTCON meetings; donations of materials and, especially, chemical literature through Project Bookshare; collaboration in producing CHEMRAWN conferences; and environmental chemistry activities.
Green chemistry and the global water crisis
Authors: Hjeresen Dennis L.
Published: October 2007

Among environmental issues facing the world today, land-based sources of water pollution is one of the most pressing. Adequate supplies of satisfactory-quality water are essential for the natural resources and ecological systems on which all life depends. Green chemistry offers a scientifically based set of solutions to protect water quality.
Green chemistry as systems science
Authors: Graedel Thomas E.
Published: October 2007

Green chemistry does not operate as an isolated subsystem, but within higher levels of corporation and society. From an environmental standpoint, the ideal focus is to achieve optimum performance across the system, not at a single systems level. This paper proposes a four-level system for green chemistry and provides examples of performance at each level that can legitimately be termed sustainable.
Centre for Green Chemistry, Monash University, Australia
Authors: Scott Janet L. , Raston Colin L. , Strauss Christopher R. , Jackson W. Roy
Published: October 2007

The Centre for Green Chemistry is an Australian Research Council (ARC) Special Research Centre (SRC), located at Monash University in Melbourne, Australia. SRCs are funded by the Australian federal government, via the vehicle of the ARC, with the express goal of supporting excellent basic research and research training that has strong international links. The goal of the center is to provide a fundamental scientific base for future green chemical technology, identifying niche areas in the Australian context and beyond. Establishment of this SRC and its modus operandi are discussed.
Teaching green chemistry. Third-year-level module and beyond
Authors: Raston Colin L. , Scott Janet L.
Published: October 2007

Teaching green chemistry at Monash University started in earnest in 1999 with the launch of a 12-lecture final year undergraduate course. The course was designed to introduce students to the field of green chemistry. The students had no prior knowledge of the field or indeed what green chemistry meant. The course covered a definition of green chemistry, historical issues, and challenges, together with an introduction to the principles and tools of green chemistry, evaluating the effects of chemistry and technology, general areas of green chemistry, and presenting examples of successful and developing green chemistry technologies. Several general references were used, although specific examples were from the primary literature. Another feature of the course was the analysis of recent papers. In addition, experiments linking into the course have been developed, and there are plans for postgraduate training, professional development, and community outreach involving postgraduate candidates.
Integrating green chemistry and sustainability into a specialty chemical company
Authors: Reinert Kevin H.
Published: October 2007

Most companies have embraced the American Chemistry Council (ACC) Responsible Care" program, including Product Stewardship, and are integrating ISO 14001 and other environmental management systems. The Rohm and Haas Company uses environmental improvement objectives that not only focus on compliance with existing regulations and industry trends, but for developing business unit-driven objectives to reduce our environmental footprints for processes and systems. To attain the next level of strategic environmental management, integration of sustainable concepts and activities into a general management framework, new product development and corporate decision-making processes must occur. Businesses need to internalize that operating sustainably creates long-term value, achieves a greater competitive edge, and is not solely a short-term cost-reduction activity. They must recognize and foster implementation of technological advances in green chemistry, life-cycle analysis, risk assessment, and engineering consistent with specific business goals. Development of sustainability improvement objectives for each business unit assists in meeting our global sustainability goals. The process, measures and metrics, challenges, and results for integrating sustainability into the culture at Rohm and Haas will be described during this presentation.
Supercritical fluids-assisted micronization techniques. Low-impact routes for particle production
Authors: Reverchon Ernesto , Porta Giovanna Della
Published: October 2007

Micronized powders are of interest in many industrial fields; pharmaceuticals, catalysts, pigments, and biopolymers, for example, are some categories of products that can be used as micro-sized particles. Traditional techniques used to produce micronic powders are based on high-temperature reactions that require high energies, on jet milling that is characterized by low efficiencies and mechanical stress, and on liquid solvents precipitation that has a poor control on particle size and can pollute the product. Generally, the control of the powder size and the span of its distribution are still very approximate.

In the last few years, several supercritical fluids-based techniques have been proposed for the production of micronic and nanometric particles. These processes try to take advantage of some specific properties of gases at supercritical conditions such as enhanced solubilization power and its modulation, large diffusivities, solventless or organic solvent reduced operation, and the connected possibility of controlling powder size and distribution. Techniques like the rapid expansion of supercritical solutions (RESS), supercritical antisolvent precipitation (SAS), particle generation from gas-saturated solutions (PGSS), and new atomization processes have been critically reviewed in this work.
Green electrochemistry. Examples and challenges
Authors: Matthews Michael A.
Published: October 2007

Electrochemical methods have been proposed for synthesis of organic compounds, including conversion of CO2. Such methods may provide a basis for environmentally friendly and sustainable methods for chemical production. Nevertheless, electrochemical syntheses are not widely utilized. Several examples of ongoing research are presented that illustrate both the opportunities as well as the challenges associated with the utilization of electrochemistry for green chemical manufacturing.
Solvent-free preparation of ionic liquids using a household microwave oven
Authors: Varma Rajender S. , Namboodiri Vasudevan V.
Published: October 2007

An efficient solventless protocol for the preparation of a wide variety of ionic liquids is described, which requires a simple exposure of admixed 1-methylimidazole and alkyl halides to microwave irradiation in open glass containers. The details of this clean process using a common household microwave oven, which exploits the newer inverter technology system for better power attenuation, are described. The characterization and thermal stability data on selected ionic liquids and their potential applications are summarized.
Recoverable catalysts. Ultimate goals, criteria of evaluation, and the green chemistry interface
Authors: Gladysz John A.
Published: October 2007

Attempts are made to define the "ideal synthesis", "ideal catalyst", and "ideal recoverable catalyst". Although these unattainable limits can never be realized, they help to focus attention on attributes chemists should strive for. Criteria for evaluating catalyst recovery are analyzed, and increased attention to the critical and constructive evaluation of competing "green" chemical technologies is advocated.
Modeling lifetime and degradability of organic compounds in air, soil, and water systems (IUPAC Technical Report)
Authors: Sabljic A. , Peijnenburg W.
Published: October 2007

Degradability of organic compounds in air, soil, and water is the most important factor for evaluating their environment fate as well as possible adverse effects to humans and the environment. The primary degradation process in the troposphere is the reaction with the hydroxyl radical. For water and soil compartments, the primary degradation process is biodegradation. The objectives of this report are: (i) to review published models and their evaluation studies, (ii) to perform an in-house evaluation of general models for estimating tropospheric degradation and biodegradation of organic compounds, and (iii) to recommend reliable procedures for estimating degradability of organic compounds in the environment. The extensive evaluation procedure has shown that the most accurate method for estimating tropospheric degradation is Atkinson's group contribution method. Although this method has some limitations, it seems to be a method of choice. A viable alternative to Atkinson's method is a direct calculation, performed today almost routinely, of the reaction rate constants with hydroxyl radicals. Recently, a methodology based on reliable semiempirical potential energy surfaces was developed that enables the calculation of reaction rate constants within a factor of 2 of their measured values. A partial least squares (PLS) model and a set of seven biodegradation rules have been found to be the most reliable in estimating complete biodegradation of organic compounds. However, it is recommended to use all four evaluated methods to estimate biodegradation in the environment. If their results agree, such estimates are very reliable.
New developments in A1 and A2 adenosine receptor antagonists
Authors: Kieć-Kononowicz K. , Drabczyńska A. , Pękala E. , Michalak B. , Müller C. E. , Schumacher B. , Karolak-Wojciechowska J. , Duddeck H. , Rockitt S. , Wartchow R.
Published: October 2007

The aim of this article is to briefly present progress in the development of the potent adenosine receptor (AR) antagonists with high selectivity for either A1, A2A, or A2B ARs. The structural requirements for each AR subtype were discussed as well as their potential therapeutic use. In the search for new AR antagonists, series of imidazo-, pyrimido-, and diazepino-purindione derivatives as well as oxazolo-, oxazino-, and oxazepino-purindiones were designed, synthesized, and preliminarily evaluated in pharmacological studies. Oxygen-containing tricyclic derivatives were shown to be moderately potent AR antagonists exhibiting selectivity either for A1 or A2A ARs. Tricyclic purindiones with nitrogen in the third ring were generally more A2A AR selective. The compounds tested in vivo according to the Antiepileptic Drug Development Program of the National Institutes of Health (USA) were generally active as anticonvulsants in chemically induced seizures.
Antitumor acridines with diaminoalkylo pharmacophoric group
Authors: Konopa Jerzy
Published: October 2007

The substitution of acridine molecule in positions 1 and/or 4 with diaminoalkylo residue may result in obtaining derivatives displaying antitumor activity. The diaminoalkylo residue can be attached to acridine either directly or indirectly as a carboxamido moiety. In the former case, the presence of appropriate substituent in position para to diaminoalkylo residue is crucial for antitumor activity. Also, heterocyclic aromatic rings condensed with the acridine core can be considered as such substituents. Additional substituents introduced into the acridine core, especially those that may be transformed into quinoid systems, significantly increase antitumor activity of modified analogs. It is, however, of utmost importance that the presence of diaminoalkylo residue is the indispensable prerequisite for biological activity of acridines. Among several groups of synthesized diaminoalkyloacridines, the most potent antineoplastic properties toward a wide spectrum of transplantable tumors are exhibited by acridine-4-carboxamides, imidazo-, triazolo-, and pyrazoloacridinones. Two derivatives belonging to the above groups, acridine-4-carboxamide DACA and imidazoacridinone C-1311, are currently in clinical trials. Other derivatives exhibiting potent antitumor activity, that could be considered as close analogs of diaminolkyloacridines, are pyrazoloacridines, one of which is currently under clinical evaluation.
Retinoic acid and analogs as potent inducers of differentiation and apoptosis. New promising chemopreventive and chemotherapeutic agents in oncology
Authors: Simoni Daniele , Rondanin Riccardo , Baruchello Riccardo , Roberti Marinella , Rossi Marcello , Grimaudo Stefania , D'Alessandro Natale , Invidiata Francesco Paolo , Tolomeo Manlio
Published: October 2007

In this report we will describe the preparation and the biological activity of a novel class of heterocyclic arotinoids endowed with potent cytotoxic and apoptotic acitivity. Structure­activity relationship studies revealed that the different stereochemistry at the C9 double bond of retinoids seems associated with a different biological activity: potent apoptotic activity for the cis-isomers, whereas differentiating activity for the trans structures. An interesting modified Wittig procedure that allows easily to arotinoids will also be described. The substitution of the alkenyl portion with a more flexible oxymethyl or aminomethyl moiety gave compounds with poor activity, whereas isoxazole-bridged arotinoids allowed compounds active also on multidrug-resistant (MDR) leukemia cell lines.
New small-molecule tubulin inhibitors
Authors: Bacher G. , Beckers T. , Emig P. , Klenner T. , Kutscher B. , Nickel B.
Published: October 2007

The variety of biological agents directed toward the tubulin system exceeds those acting on DNA, making it an important target for cancer chemotherapy. However, the complicated chemical structures and restricted access to the natural resources, in combination with the development of drug resistance, limit the first generation of natural products. Considerable efforts in the search and synthesis of new synthetic compounds, such as small molecular tubulin inhibitors, gave access to novel potential/promising drugs. Among these substances, two series of novel, easily accessible indole classes were identified as tubulin-destabilizing agents. Owing to the synthetic nature, potent in vitro and in vivo antitumoral activity, and efficacy against multidrug-resistant (MDR) tumors, D-24851 and D-64131 have significant potential in cancer treatment.
Gradient HPLC in the determination of drug lipophilicity and acidity
Authors: Kaliszan Roman , Haber Piotr , Baczek Tomasz , Siluk Danuta
Published: October 2007

The linear-solvent strength (LSS) model of gradient elution in high-performance liquid chromatography (HPLC) has been demonstrated to provide parameters of lipophilicity and acidity of analytes. pKa and log kw values are determined in three gradient runs. The first two experiments use an aqueous buffered eluent with a wide-range organic modifier gradient at pH of buffer, providing suppression of ionization of the analyte. That experiment allows an estimate of contents of the organic modifier in the mobile phase (%B), producing requested retention coefficient, k, for the nonionized form of the analyte. The next experiment is carried out with the latter %B and a pH-gradient of the aqueous component of the eluent that is sufficient to overlap possible pKa value of the analyte. The initial pH of the buffer used to make the mobile phase is selected to insure that the analyte is in nonionized form. The resulting retention time allows an estimate of pKa in a solvent of the given %B.

The log kw parameter obtained correlated well with the corresponding value obtained by the standard procedure of extrapolation of retention data determined in a series of isocratic measurements. The correlation between log kw and the reference parameter of lipophilicity, log P, was very good for a series of test analytes. The values of pKa were found to correlate with the literature pKa data determined in water for a set of aniline derivatives studied.
Rational design and synthesis of homochiral azole antifungal agents
Authors: Botta Maurizio , Corelli Federico , Manetti Fabrizio , Mugnaini Claudia , Tafi Andrea
Published: October 2007

The first synthesis of both enantiomers of the antifungal drug bifonazole (1a) and related imidazole compounds 1i and 5b,c is described, starting from enantiomerically pure or enriched amines 6a­d. Construction of the imidazole ring on amines 6a­d was performed in a straightforward manner affording the final compounds in good overall yield and with very high enantiomeric purity, as determined by enantioselective HPLC. Biological evaluation in vitro of the single enantiomers of 1a,i and 5b,c against different strains of Candida albicans did not show any enantioselectivity. Finally, the pseudoreceptor modeling technique was applied to generate a model able to explain and predict the inhibitory activity of azole compounds against C. albicans P45014DM.
Combinatorial chemistry. Facing the challenge of chemical genomics
Authors: Darvas Ferenc , Dorman Gyorgy , Urge Laszlo , Szabo Istvan , Ronai Zsolt , Sasvari-Szekely Maria
Published: October 2007

In the age of high-throughput screening and combinatorial chemistry, the focus of drug discovery is to replace the sequential approach with the most effective parallel approach. By the completion of the human gene-map, understanding and healing a disease require the integration of genomics, proteomics, and, very recently, metabolomics with early utilization of diverse small-molecule libraries to create a more powerful "total" drug discovery approach.

In this post-genomic era, there is an enhanced demand for information-enriched combinatorial libraries which are high-quality, chemically and physiologically stable, diverse, and supported by measured and predicted data. Furthermore, specific marker libraries could be used for early functional profiling of the genome, proteome, and metabolome. In this new operating model, called "combinatorial chemical genomics", an optimal combination of the marker and high-quality libraries provides a novel synergy for the drug discovery process at a very early stage.
Miniaturization and chip technology. What can we expect?
Authors: Manz Andreas , Eijkel Jan C. T.
Published: October 2007

Miniaturization and chip technology play an important role for analytical chemistry instrumentation in the future. A brief theory of the relevant microfluidics with reasons for miniaturization is given.
Capillary electrophoretic techniques toward the metabolome analysis
Authors: Terabe Shigeru , Markuszewski Michal J. , Inoue Naoko , Otsuka Koji , Nishioka Takaaki
Published: October 2007

Metabolome analysis is a systematic chemical analysis of metabolites, which may be used to investigate the metabolic activity in the cell. Capillary electrophoresis (CE) is one of the most promising techniques for the metabolome analysis, because it gives high-resolution separations in a reasonable time and requires a minimum amount of samples. General characteristics of CE are discussed from the viewpoint of metabolome analysis. Micellar electrokinetic chromatography (MEKC), a separation mode of CE, enables the separation of neutral analytes by using micelles as pseudostationary phases. MEKC is also powerful for the separation of ionic analytes to improve selectivity. To solve relatively poor concentration sensitivity with UV absorbance detection, on-line sample preconcentration techniques were developed resulting in up to few thousand-fold increases in sensitivity. Laser-induced fluorescence detection is another solution to increase concentration sensitivity, but most analytes are not natively fluorescent. Therefore, several derivatization reactions were performed to selectively detect a class of analytes with high sensitivity. Some preliminary results are shown with formic acid extracts of Bacillus subtilis.
Threading intercalation to double-stranded DNA and the application to DNA sensing. Electrochemical array technique
Authors: Takagi Makoto
Published: October 2007

Electrochemical labeling of double-stranded (ds) DNA is achieved by redox-active DNA intercalators. Threading intercalators derived from naphthalenediimide appended with ferrocene reporter group in the side arms are particularly useful for this purpose. This allows a sensitive electrochemical detection of DNA hybridization on an array, providing a great potential for low-cost, high-throughput, and quick DNA screening technique in post-genome study.
Selective detection of neurotransmitters by fluorescence and chemiluminescence imaging
Authors: Wang Ziqiang , Yeung Edward S.
Published: October 2007

In recent years, luminescence imaging has been widely employed in neurochemical analysis. It has a number of advantages for the study of neuronal and other biological cells: (1) a particular molecular species or cellular constituent can be selectively visualized in the presence of a large excess of other species in a heterogeneous environment; (2) low concentration detection limits can be achieved because of the inherent sensitivity associated with fluorescence and chemiluminescence; (3) low excitation intensities can be used so that long-term observation can be realized while the viability of the specimen is preserved; and (4) excellent spatial resolution can be obtained with the light microscope so subcellular compartments can be identified. With good sensitivity, temporal and spatial resolution, the flux of ions and molecules and the distribution and dynamics of intracellular species can be measured in real time with specific luminescence probes, substrates, or with native fluorescence. A noninvasive detection scheme based on glutamate dehydrogenase (GDH) enzymatic assay combined with microscopy was developed to measure the glutamate release in cultured cells from the central nervous system (CNS). The enzyme reaction is very specific and sensitive. The detection limit with CCD imaging is down to mM levels of glutamate with reasonable response time. We also found that chemiluminescence associated with the ATP-dependent reaction between luciferase and luciferin can be used to image ATP at levels down to 10 nM in the millisecond time scale. Similar imaging experiments should be feasible in a broad spectrum of biological systems.
Ultrafast dynamics at solid/liquid interfaces as investigated by photothermal spectroscopy
Authors: Sawada Tsuguo
Published: October 2007

Among the recent topics of photothermal (PT) applications of lasers, we focus on ultrafast (<=1.0 ns) photothermal/photoacoustic (PT/PA) phenomena occurring at interfaces, which play important roles in nanoscale materials science and technology. Here, we describe our recently developed novel PT techniques called transient reflecting grating (TRG) spectrometries. These techniques have been applied to the studies of solid surfaces, film substrates, and solid/liquid interfaces.
Standards in isothermal microcalorimetry (IUPAC Technical Report)
Authors: Wadsö Ingemar , Goldberg Robert N.
Published: October 2007

The main calorimetric principles used in isothermal microcalorimetry are briefly discussed. Different chemical calibration and test reactions are discussed, with a focus on reactions suitable for ambient conditions: reactions initiated by mixing of liquids (including titration microcalorimetry), dissolution of solid compounds and of slightly soluble gases, a photochemical process, and thermal power signals released over an extended period of time. Guidelines on the use of standardized chemical test and calibration reactions in isothermal microcalorimetry are presented. A standardized terminology in reporting characteristics of isothermal microcalorimeters is proposed.
Critical evaluation of stability constants of phosphonic acids (IUPAC Technical Report)
Authors: Popov Konstantin , Rönkkömäki Hannu , Lajunen Lauri H. J.
Published: October 2007

Available experimental data on stability constants of proton and metal complexes for 10 phosphonic acids [methylphosphonic acid, 1-hydroxyethane-1,1-diylbisphosphonic acid, dichloromethylenebisphosphonic acid, amino-methanephosphonic acid, N-(phosphonomethyl)glycine, imino-N,N-bis(methylenephosphonic acid), N-methylamino-N,N-bis(methylenephosphonic acid), nitrilotris(methylenephosphonic acid), 1,2-diaminoethane-N,N,N´,N´-tetrakis-(methylenephosphonic acid), and diethylenetriamine-N,N,N´,N´´,N´´-pentakis-(methylenephosphonic acid)], published in 1950­1997, have been critically evaluated. For the latter phosphonate, all the data are rejected, as well as protonation constants [HL]/[H][L] for three other ligands. Higher-quality data are selected and presented as "Recommended" and "Provisional".
Theories of structural and dynamic properties of ions in discrete solvents. Application to magnetic resonance imaging
Authors: Fries Pascal H. , Richardi Johannes , Rast Sebastian , Belorizky Elie
Published: October 2007

The molecular Ornstein­Zernike (MOZ) formalism used to compute the structure of a liquid solution is briefly presented. Its ability to describe the equilibrium properties of aprotic solvents and of their electrolyte solutions is demonstrated from selected examples. The potential of mean force and the relative motion of ions in water are studied by the powerful method of intermolecular nuclear magnetic relaxation dispersion (NMRD) in paramagnetic solutions. The interest of the ion­ion dynamics in medical magnetic resonance imaging (MRI) is shown by a typical NMRD study involving paramagnetic gadolinium Gd3+ complexes.
Using simulation to study solvation in water
Authors: Lynden-Bell R. M. , Rasaiah J. C. , Noworyta J. P.
Published: October 2007

Simulations of simple solutes (charged and uncharged spheres) in model water have been performed in order to elucidate aspects of solvation in water at ambient and supercritical states. The variation of solvation entropy as a function of solute charge has been used to investigate hydrophobic and hydrophilic ordering and the structure-making and structure-breaking effects of ions. Simulations with model solvents, which differ from water in certain features, have been used to try to identify the particular properties of water that are associated with these phenomena.