Enumerated structure

Fig. 1. A combinatorial library represented as an R-group structure, and two enumerated structures.

On the other hand, the enumerated structures themselves might be useful as input for other computer programs that generate computational data, such as QSAR or other chemical property predictions. Since these programs accept and work on individual specific structures, these structures must be generated both for input to these programs and for association with their output. This capability is important for the process of designing new combinatorial libraries. 

A suite of programs for combinatorial chemistry—Legion to build and store virtual libraries, CombiLibMaker to enumerate structures, Selector to define diversity measures to select diverse subsets of structures, and DiverseSolutions to apply chemi-... 

Member Either lal a particular substituent at a given position in a generic structure (an R-group member) or Ih) an enumerated structure of a generic library, which corFe.spunds to a given selection of substituents (a member of a library). 

Estrogenic activity in mammals is mediated by several estranes. A good number of these compounds are better known by their trivial as opposed to systematic names. The estrane nucleus is fairly similar to a gonane in that the double bonds in ring A are actually enumerated. Structure 4-1 (Scheme 4) thus becomes estra-l,3,5-trien-17-one. This steroid is far better known as estrone. Its reduced counterpart 4-2 is named estra-l,3,5-triene-3,17/3-diol. The more prevalent name for this compound is estradiol or, somewhat less commonly, /3-estradiol, The isomer with the hydroxyl group below the plane of the paper is named estra-l,3,5-trien-17a-ol or a-estradiol. The systematic name for the methyl ether of estradiol becomes 3-methoxyestra-l,3,5-trien-17/3-ol. The product 4-4 from alkylation at position 17 can be named 17)8-methylestra-l,3,5-trien-17a-ol. That compound is also known as equilin, a name derived from the fact that it was first isolated from horse urine. An additional double bond as in 4-5 is simply added to three already present, thus estra-... 

The analyst next starts the Decode ChromRead application to associate a decode.report.txt file with each well of each plate. The Decode main application is run to convert the data for each well into an enumeration string ACLxxxx-Afaaaa-Afbbbb-Afcccc. The Code-to-Structure apphcation creates an ISIS database of these enumerated structures. As a final step the analyst uses the EICCAPTURE application in Access to generate the EIC-CAPTURE text files for use in CAPTURE. 

Enumerating Structures Are there any isomers of decane having seven methyl groups ... 

Enumerating structures with molecular descriptors. Enumerating molecules matching molecular descriptors or topological descriptors is a longstanding problem. Surprisingly, few reports in the literature provide answers to the question. Most of the proposed techniques are stochastic in nature and are reviewed in the Sampling Structures section. In a series of five papers, Kier, et reconstruct molecular structures from the count of paths... 

All the so-called failures of VB theory are due to misuse and failures of very simplified versions of the theory. Simple resonance theory enumerates structures without proper consideration of their interaction matrix elements (or overlaps). It will fail whenever the matrix element is important as in the case of aromatic versus antiaromatic molecules, and so on. The hybridization... 

The term virtual library is used quite frequently in the literature these days. Unfortunately there is no common definition on what a virtual library really is. In the simplest case it is a database of fully enumerated structures of products that are under consideration to be made. The generation of such a virtual library involves software that maps the reaction sequence and the corresponding sets of building blocks onto a combinatorial representation (7) (see Note 4). This combinatorial representation can be partially or fully enumerated to generate product structures, which are then stored in structural databases (see Note 5). Subsequently, properties and descriptors to be used in the selection process are to be calculated. As there are limitations in terms of file size etc., such virtual libraries cannot hold more than a few million products. This makes it necessary to filter out reagents (see Subheading 1.3.) prior to construction of the virtual library. 

Create Unity database from enumerated structure list using program dbimport dbimport -database homopips.XI.tdb -type sin homopips.XI.chom... 

For registration purposes enumerate structures using selected reagents from both variation sites. First extract registration ids of reagents ... 

Most of the descriptors discussed in this review require an enumerated structure, i,e., the full connection table of the reference molecule. For combinatorial libraries and for certain kinds of descriptors, this is not necessary. Downs and Barnard have recently presented an elegant method to compute molecular fingerprints based on the precursors, using techniques developed for Markush structure handling in chemical patents,... 

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