Chemical structure analogs

Entrez history is used heavily by PubChem tools (which are not a part of Entrez) so results of user searches can be used as a subset for further manipulation. Eor example, the chemical structure download service (described below) reads Entrez history items, so one can generate an SDF file containing just those compounds found in a PubChem Compound Entrez result set. For example, the BioAssay tools (also described below) make frequent use of Entrez history, so that structure queries can be used to subset assay results in a chemical structure analog series. 

Another approach applies graph theory. The analogy between a structure diagram and a topological graph is the basis for the development of graph theoretical algorithms to process chemical structure information [33-35]. 

Mathematical predictive modeling based on predictive equations. Analogous chemical structures. Employers would rely on service life values from other chemicals having analogous chemical structure to the contaminant under evaluation for breakthrough. 

There are a number of other synthetic substances analogous with or approximating to the cinchona alkaloid structure which it is more convenient to deal with in discussing the correlation of chemical structure with pharmacological action in this group (p. 469). 

Fig. 1 Chemical structures of backbone modifications used in therapeutic nucleic acid analogs. Shown are the unmodified DNA/RNA chemical structures in addition to a selection of first (PS), second (OMe, MOE), and third generation (PNA, LNA, MF) nucleic acid modifications...

Sheehan, l.C. Johnson, D.A. (1954) The Synthesis of Substituted Penicillins and Simpler Structural Analogs. VIII. Phthalimidomalonaldehydic Esters Synthesis and Condensation with Penicillamine. Journal of the American Chemical Society, 76, 158-160. 

In the recently published structural analog approach [44], logP of unknown chemicals is calculated from the known experimental log P of their closest struc-... 

Chemical Structures. Figure 1 shows the chemical structures for 14 phenylethylamine compounds. Nine of these compounds are used clinically as anorectics (ii-amphetamine, phentermine, diethylpropion, phenmetrazine, phendimetrazine, clotermine, chlorphentermine, benzphetamine, and fenfluramine). Four of these compounds are not approved for clinical use and are reported to have hallucinogenic properties (MDA, PMA, DOM, and DOET). The final compound ( /-ephedrine) is used clinically for bronchial muscle relaxation, cardiovascular, and mydriatic effects. Figure 2 shows the chemical structure for MDMA, the methyl analog of MDA. MDMA is not approved for clinical use and has been reported to produce both LSD-like and cocaine-like effects. 

This closure property is also inherent to a set of differential equations for arbitrary sequences Uk in macromolecules of linear copolymers as well as for analogous fragments in branched polymers. Hence, in principle, the kinetic method enables the determination of statistical characteristics of the chemical structure of noncyclic polymers, provided the Flory principle holds for all the chemical reactions involved in their synthesis. It is essential here that the Flory principle is meant not in its original version but in the extended one [2]. Hence under mathematical modeling the employment of the kinetic models of macro-molecular reactions where the violation of ideality is connected only with the short-range effects will not create new fundamental problems as compared with ideal models. 

Clark-Lewis I, Schumacher C, Baggiofini M, Moser B. Structure-activity relationships of interleukin-8 determined using chemically synthesized analogs. Critical role of NH2-terminal residues and evidence for uncoupling of neutrophil chemo-taxis, exocytosis, and receptor binding activities. J Biol Chem 1991 266 23128-34. 

It should be clear by the definition given so far that the carbene-analogous state is limited to molecular species. The oligomer of EX2 (EX2)n is, of course, much more stable than EX2 in every respect. It should nevertheless be noted that also the oxidation number does not change in going from the monomer to the polymer the chemical, structural, and electronic properties of these species are completely different. 

Figure 10.4 Chemical structures of the clinically relevant melatonin analogs, compared with melatonin (5-methoxy-N-acetyltryptamine). Agomelatine N- 2-[7-methoxy-l-naphthalenyl]ethyl)acetamide. Ramelteon ...

Figure 1. Chemical structures of representative ligands investigated A) biotin, B) 2-(4 -hydroxyazobenzene) benzoic acid (HABA), C) charged (X=CH2) and neutral (X=NH2+) carboxylate MMP inhibitors, D) TIBO scaffold, E) sustiva, and F) hydroxyethylamine scaffold. The biotin derivatives," MMP inhibitors,19 TIBO analogs,21 and cathepsin D inhibitors22 derived from structures A), C), D), and F), respectively, have been published elsewhere.

---