Chemical information systems, complexity

Chemometrics is a chemical discipline bom for interpreting and solving multivariate problems in the field of analytical chemistry. Svante Wold used for the first time, in 1972, the name chemometrics for identifying the discipline that performs the extraction of useful chemical information from complex experimental systems (Wold, 1972). 

Chemical information systems are complex. This book does not cover every aspect of them. However, it uses a chemical registration system as an example of how to use an object-oriented approach to develop systems in the cheminformatics domain. 

A mechanism of action describes the molecular sequence of events (covalent or non-covalent) that lead to the manifestation of a response. The complete elucidation of the reactions and interactions among and between chemicals, include very complex and varied situations including biological systems (macromolecular receptors, physical phenomena (thermodynamics of explosions) or global systems (ozone depletion). Unfortunately, this level of mechanistic detail is often unavailable but recent advances in molecular toxicology and others hazards, at the molecular level, have provided valuable information that elucidates key steps in a mechanism or mode of action. ... 

Thus, the Platonic and Archimedean solids not only provide a means for host design, but a way in which to maximize chemical information, allowing the chemist to simplify the structures of complex molecular frameworks and, in effect, engineer host-guest systems. 

In order to achieve selective complexation and to perform specific functions, chemical information has to be stored in L and read out by S. Information storage may be accomplished in the design of the ligand system and readout is contained in the dynamics of the complexation process. These various definitions are interrelated in the flow chart given in Figure 1. 

Ligand-substrate complementarity extends over the various molecular features noted above. The problem of ligand design is then to analyze the properties of the substrate to be complexed, to derive the complementary chemical information to be stored in the ligand, and to devise and synthesize a ligand system containing the required information. 

SEC became the most widely used method for molar mass and molar mass distribution determination due to its broad applicability, easy sample preparation, and the large amount of information resulting from the full distribution curve. The commercially available SEC systems work automatically with small sample amounts and even at elevated temperatures. In addition, chromatographic systems coupled with spectroscopic methods giving chemical information on the separated fractions gain more and more importance for analysis of complex polymer systems and mixtures. 

In our brain, neurons store, exchange, and retrieve information by means of extremely complicated chemical processes.1160,611 Synthetic multistate/multifunc-tional systems may play the role of models in initial attempts to understand the chemical basis of complex biological processes.1201 It is not at all clear whether wet ... 

The ability to represent uniquely a chemical compound is a fundamental requirement for storage or transmission of chemical information. We define compounds by their molecular structure, as shown in two-dimensional diagrams or stored in computers. Pronounceable names have been developed for oral and written communication, ranging from the trivial, containing no structural information, to completely systematic names, which can be decoded to yield the original structure. However, the application of systematic nomenclature to complicated structures requires expert knowledge of elaborate systems of nomenclature rules. The use of systematic nomenclature to convey information about the increasingly complex molecular systems handled by today s chemists is both laborious and inefficient. 

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