SEARCH TEXT compounds

Chemical Substructure Databases. Several patent databases are searchable by chemical substmcture (99). These are designed to give higher relevance of retrieval when searching chemical compounds than the bibHographic or full-text databases. 

The listing of the spectroscopic methods of characterization may be useful if the reader searches for compounds to compare with his or her own results and may also serve as a measure of reliability for the assignment of the complex formula. The comment column indicates special features or points of interest for the complex or sections in the text where the respective compound is discussed in more detail. 

Numeric databases primarily contain numeric data on chemical compounds, such as physicochemical values and the results of series of measurements. Therefore, the files correspond to printed tables of numeric property data. Since the attributes of numeric data are different from those of text data, the search has to be managed... 

Structure databases are databases that contain information on chemical structures and compounds. The compounds or structure diagrams are not stored as graphics but are represented as connection tables (see Section 2.4). The information about the structure includes the topological arrangement of atoms and the connection between these atoms. This strategy of storage is different from text files and allows one to search chemical structures in several ways. 

All chemical shift data presented in this book come either from the primary literature or from spectra obtained in the author s laboratory. All spectra actually depicted in the book derive from spectra obtained by the author at the University of Florida. All data from the literature were obtained via searches using MDL Crossfire Commander or SciFinder Scholar. Persons interested in accessing such primary literature can do so readily via these databases by simply searching for the specific compound mentioned in the text. 

Regarding the multitude of NMR chemical shifts of specific compounds that are provided within the text, references for chemical shifts of individual compounds for the most part will not be cited. It is assumed that if such references are required, the reader can find them by a quick search using either MDL Crossfire Commander or SciFinder Scholar. The author found MDL Crossfire Commander the superior database for locating specific NMR data. 

A tabular search using the Fact Editor for the conditions [bp > -40] AND [bp < 0] yields 462 hits in 15 s. Since most of the hits contain heteroatoms other than fluorine, it would be better to reissue the search command for compounds that do not contain any nitrogen [bp > - 40] AND [bp < 0] NOT [ N ], which yields 317 hits in 156 s. The asterisk indicates the wild card that stands for any number of characters of any kind, and the is for a text string. When we refine it further to exclude chlorine... 

The database search process starts with a rapid screening process within which molecules possessing properties required from potential hits are sorted out from those that can be excluded a priori. The screen involves substructure match followed by screens matching three-dimensional pharmacophore features, molecular shapes or exclusion volumes and text constraints (ID properties) if present in the query (through Oracle). All this greatly reduces the number of potential hit compounds in the database. The next step of the search pro-... 

Table IV contains a listing of the substances whose administration has been reported as increasing the urinary glucuronic acid, and of compounds for which some evidence for glucuronic acid conjugation exists, but of which no glucuronic conjugate has actually been isolated. The compounds of Table III and, usually, their metabolic precursors have been omitted. Here, except as noted, specific references to the literature will be found in Williams text.1 Unfortunately, this list is not complete some of the references were found only by careful search, and there are probably many more buried in the literature.

Figure 12.2. Advanced search for PDB file. From the PDB home page, select Advanced search field to open the PDB Search Fields form as shown. The advanced search enables the user to customize search fields including PDB identifier, author, chain types (protein, enzyme, DNA, and RNA, etc.), compound information, PDB header, experimental technique, text search, and result display options.

This review presents a perspective of the important structural and synthetic studies reported in 2008. The strict definition of an organometallic compound as one containing at least one C-metal bond or contact has been used throughout the literature survey. As with previous years this review is not intended to be comprehensive, although it is based on a comprehensive search. Individual topics are highlighted in bold in the text in order to facilitate rapid access to a particular area of the literature. Research in 2008 on Group 2 and 12 organometallics was dominated by structural studies of novel types of compounds. This is reflected in the focus of the review for this year. 

A number of NMR spectral databases exist to aid the natural product chemist in structure elucidation. Speclnfo currently contains 359000 13C NMR spectra and 130 000 3H NMR assigned spectra.106 CSearch is another repository with a number of data sets.107 Both Speclnfo and CSearch provide structure prediction based on the database content. NMRShiftDB is an open access, open submission NMR web database for structures and their NMR spectra. It allows users to predict spectra and search for spectra and structures.108,109 NMRPredict is offered with MestReNova and predicts ll and 13C spectra from a structure.110 The Madison Metabolomics Consortium Database (MMCD http //mmcd.nmrfam.wisc.edu/) is a web-based bioinformatics resource that contains experimental NMR data on 447 compounds.111 Additionally, the system contains information on more than 20 000 small molecules and can be queried using text, structure, NMR, mass and miscellanea.111,112 ChemGate allows users to search for NMR data by structures or substructures and also predicts NMR spectra.113... 

In addition to the published literature, a chemical shift database is being developed by Advanced Chemistry Development (AC D/Labs) that can be used interactively by an investigator both to predict chemical shifts for a molecule being investigated and to search the database by a multitude of parameters, including structure, substructure, and alphanumeric text values. This database is accessible in the NNMR software package offered by ACD/Labs and presently contains data on more than 8800 compounds with over 20 700 chemical shifts. Examples of the use of the NNMR database will be presented later in this chapter. 

Organoaluminum compounds are heavily used in organic synthesis and the pertinent literature is too extensive to be adequately reviewed here. Readers are directed to excellent articles by Eisch for a general overview of the subject and are encouraged to search for specific transformations in the texts published by March and Larock. The text by Ojima cites several examples of enantioselective reactions using chiral complexes of aluminum. 

Free patent information is provided by the website http //www.freepatentsonline.com/, covering U.S., EP, and PCT patents/applications and Japanese patent abstracts. In addition to the usual text-based searches in various search fields, this site also enables graphically input chemical structure searches to be performed on over 9 million compounds (including prophetic compounds) using exact structure, substructure, or chemical similarity searches. Chemistry searches using SMILES strings or chemical names are also possible. Full patent documents may be viewed in text or PDF format. 

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