The Combined Chemical Dictionary (CCD) Web Version is a chemical database containing over 475,000 substances which are formerly available from the following products:
Dictionary of Analytical Reagents (14,000
compounds)
Dictionary of Carbohydrates (22,000 compounds)
Dictionary of Inorganic and Organometallic Compounds (101,000 compounds)
Dictionary of Natural Products (170,000 compounds)
Dictionary of Organic Compounds (255,000 compounds)
Dictionary of Drugs (formerly PharmaSource) (41,000 compounds)
The information contained on the chemical database includes descriptive and numerical data on chemical, physical and biological properties of compounds; systematic and common names of compounds; literature references; structure diagrams and their associated connection tables.
What sort of compounds are in CCD?
In general, CCD contains the following compounds:
Data Representation and Organisation
1. Derivatives and variants
In the database, closely related compounds are grouped together
to form an entry. Stereoisomers and derivatives of a parent compound are all
listed under one entry. The compounds in The Chapman & Hall/CRC Combined
Chemical Dictionary are grouped together into approximately 160,000 entries.
The structure of an entry is shown below.
A simple entry covers one compound, with no derivatives or
variants. A composite entry will start with the entry compound, then may have:
- one or more derivatives at entry level
- one or more variants of the entry
- one or more derivatives of the variant.
Variants may include stereoisomers, e.g. (R)-form, endo-form; members of a series of natural products with closely related structures such as antibiotic complexes. Molecular formulae are included for nearly all of these derivatives and so are readily searchable, whether they are documented as derivatives or have their own individual entry. Molecular formulae are not in general given for salts, hydrates or complexes (e.g. picrates) nor for most "characterisation" derivatives of carbonyl compounds such as 2,4-dinitro-phenylhydrazones and semicarbazones. Where a derivative appears to have been characterised only as a salt, the properties of the salt may be given under the heading for the derivative. In such cases the data is clearly labelled, e.g. Mp 179°: (as hydrochloride). Where a compound can exist in several stereoisomeric forms, these isomers are grouped together into a single entry. Where known, physical properties, CAS registry numbers and pharmacological activity are assigned for each isomer.
2. Antibiotic Complexes and Biologicals
Many structurally related antibiotics co-occur as metabolites of the same producing organism, and these are presented within a single entry e.g. Actaplanin. Usually these components will only differ from each other in side chains or sugar residues and can be presented with a single structure diagram, suitably annotated. Complex biological molecules such as hormones have been treated in a similar manner, with closely related species variants subsumed into a single entry. An example is Calcitonin.
3. Anions and Cations
For ionic substances such as quaternary ammonium salts, the entry refers to the anion or cation, and the molecular formula and molecular weight given are those of the ion. The various salts (e.g. chloride, nitrate) are treated as derivatives, each with its own molecular formula.
4. Isotopically Labelled Compounds
In general the coverage of CCD does not extend to isotopic variants. In cases where isotopes are used either medicinally or diagnostically, an entry for the unlabelled compound has been compiled and contains an explanation of the uses, plus additional CAS numbers applying to the isotopically labelled compound.
5. Minerals
Wherever possible, minerals corresponding to synthetic compounds are included within the entry for the synthetic compound, e.g. Zinc Blende and Wurtzite are incorporated into the entry for Zinc Sulfide (ZnS). Only when the mineral is the sole point of interest or unavailable synthetically is it given an entry in its own right.
Tautomerism
A completely consistent scheme for covering all such entries
is not possible or desirable. Some variation is necessary in the way the appropriate
CCD entries are organised in order to cover the various possibilities, but it
is hoped and believed that the maximum possible clarity has been achieved. The
general principles which have been followed are described here using as an illustration
one of the commonest types of tautomerism exhibited by simple organic compounds,
which is heterocyclic NH 
OH prototropy as exemplified by 2- and 4-hydroxypyridines.
OH tautomerism
of the type shown (although they may tautomerise to zwitterionic tautomers). P(S)OH interconversion shown by many
organophosphorus compounds and the degenerate NH NH tautomerism of pyrazoles and imidazoles.
The same general principles have been followed and should be clear from inspection
of the individual entries. For some types of organophosphorus tautomerism,
e.g. phosphinic acids RPH(O)OH
phos-phonous acids RP(OH)2, separate entries for the two substances
have been retained. Abbreviations are frequently used within the text.
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The Accurate Mass field contains all the accurate masses of compounds (quoted to 6 decimal places) reported in the entries. You can search for accurate mass ranges as well as for individual values (see Range searching).
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This field enables you to select all of the entries in the database. If you wish to retrieve all of the entries in the Combined Chemical Dictionary web version, type Y in the search box. You can use this field to carry out exclusion searches. To find all compounds that do not contain sulfur, for example, enter the search terms as follows:
All Entries Y
NOT
Molecular Formula S
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The All Text field contains all individual words and character strings from within a particular entry. These include physical description, synthesis, use of compound, biological source, therapeutic use, hazard and toxicity as well as general/miscellaneous information.
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This field contains concise information regarding a compound's natural source, e.g. 'Insect pheromone from boll weevil, Anthonomus grandis', 'Metab. of Streptomyces psammoticus'. This information is also searchable in the All Text field. See also Truncation and Wildcards.
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This field contains concise information regarding the biological function of a compound. e.g. 'HIV reverse transcriptase inhibitor' or 'active against oomecyte fungi'. Please note that information regarding biological hazards is contained within the Hazard and Toxicity field. This information is also searchable in the All Text field. See also Truncation and Wildcards.
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This field contains a concise statement on the route by which a compound is biosynthesised in a producing organism, e.g. 'Major intermed. in the biosynth. of phaeomelanins'. This information is also searchable in the All Text field.
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This field contains boiling points reported in degrees Celsius. There is no need to put degree signs in your search term. Searches may be made on exact value or range (see Range searching).
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This field contains the pressure at which the boiling point was measured if other than at ambient atmospheric pressure. You can search for a specific boiling point pressure or for a range of values (see Range searching).
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To display an index, click on the Browse Index button, then:
(a) Type the first part of the required search term in the Index Stem box then click Go To. The correct part of the index will then be displayed. Alternatively, you can browse the index by clicking on the alphabetical links above the Index Stem box.
(b) Click on the required search term to transfer it to the Search Terms box (alternatively double click on the required search term). Additional search terms may be added by repeating step (a) - see Combining Search Terms.
(c) If you do not want to add any more search terms, click on Return to Search. You can enter search terms into as many of the search fields as you wish - see Linking Search Fields.
When you have entered the search term(s), click on the Submit Search button to carry out the search.
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This field contains the registry numbers assigned to the compounds
in the records by Chemical Abstract Services.
N.B. When entering your search term the hyphens should be included.
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This field contains all chemical names and synonyms for each compound in the database. It includes trade names, generic names for pharmaceuticals, CAS names, trivial names and semisystematic names. As there are many alternate spellings for chemicals it is best to select the term from the index. A search in the Chemical Name field will search both the primary names and the synonyms. You may use * as a wild card to indicate any number of characters and ? to indicate only one character (see Truncation and Wildcards).
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You can link the search terms using combinations of AND, OR, NOT, and you can use search relations, such as , < = when you are searching for numerical data. Use * as a wildcard to represent any number of characters. Use ? as a wildcard to represent just one character.
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A connection table is a 2-D representation of the structure and does not display any stereochemistry.
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Use this field to search for relative density if known. Density values are quoted for liquids only. This field is range searchable.
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This field allows you to restrict your search to a particular subset of the database, e.g. Natural Products, Organic Compounds, Inorganic and Organometallic Compounds, Analytical Reagents, Pharmacological Agents, Carbohydrates. Select the appropriate term from the index by first clicking on Browse Index.
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This field contains values quoted for dissociation constants in the form of pKa values. You can search for a specific dissociation constant or for a range of values (see Range Searching).
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For the main entry compound the structure will show stereochemistry and numbering systems where relevant. For a variant or a derivative compound (e.g. Et ester, oxime), the structure is derived from a 2-D connection table and does not contain stereochemical information.
Cross references to related compounds are indicated by a blue 'hot spot'. Click once and you will be taken to the cross reference entry.
Hazard and Toxicity information is displayed in red.
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You can enter the search terms in one of two ways:
1. Type the search term(s) directly into the search box on the main search page.
Typing the search term directly: You must type the term exactly as it occurs in the database, or you can use wildcards for truncating the search term, i.e. use: * to indicate any number of characters, or ? to indicate just one character. Click Submit Search to conduct a search.
2. Use the index to enter the search term(s).
To display the index, click on the Browse Index button, then:
(a) Type the first part of the required search term in the Index Stem box then click on the Go To button. The correct part of the index will then be displayed. Alternatively, you can click on the alphabetical links above the Index Stem box.
(b) Click on the required search term to transfer the search term to the Search Terms box (alternatively, double click on the required search term). Additional search terms may be added by repeating step (a) - see Combining Search Terms.
(c) If you do not want to add any more search terms, click on Return to Search. You can enter search terms into as many of the search fields as you wish - see Linking Search Fields.
When you have entered the search term(s), click on the Submit Search button to carry out the search.
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Once you have clicked the Submit Search button the results of your search are displayed as a summary list of hits, giving the names of the compounds, CAS Registry numbers and molecular formulae. The first compound in the summary list is highlighted. To display any entry simply click on the required hit.
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This field contains data on reactive, physical and toxicological hazards, including LD50 values and flash point data. All the information in this field is displayed in red typeface on the screen and is also searchable in the All Text field (see Range searching).
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This field contains an indication of whether or not there is any hazard information related to the compound. Y indicates the presence of hazard information, and N indicates that there is no hazard information. Searches for specific hazards, e.g. carcinogenic, explosive, etc, should be carried out in the Hazard and Toxicity field.
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See Technical Support.
The Index Stem box is the area on the screen that you use when searching through the index of a particular field. You should clear the Index Stem box, using the Backspace key, before you start typing into the box. Click on the Go To button to find the item you wish to enter in the Search Terms box. See also Entering search terms.
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You can change the option on the button to the left of the search field. Click on the drop-down menu to toggle between AND, OR and NOT.
Sample Search
To find all nitrogen-containing acids, enter the search term as follows:
Chemical Name *acid
AND
Molecular Formula N
If you are performing a structure search in combination with a text search, you can change the Boolean operator linking the text and structure search boxes by clicking on it and toggling between the options.
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This field contains concise information on the route by which compounds are metabolised in humans or experimental animals, e.g. 'Human metabolite of morphine'. This information is also searchable in the All Text field.
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This field contains the melting points reported in the entries in degrees Celsius. There is no need to put degree signs in your search term. You can search for a specific melting point or for a melting point range. This information is also searchable in the All Text field. See also Truncation and Wildcards.
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This field contains molecular formulae for most compounds in
the database (following the Hill convention). Formulae are not generally given
for characterisation derivatives
or salts.
Note: this field is case sensitive, i.e. capitals
and lower case must be used correctly.
The Molecular Formula index has been fragmented, i.e. a molecular formula is
stored both in its entirety (e.g. C2H5NO ) and as its components (e.g. C2, H5,
N and O). Thus, to search for all compounds that contain C30H36 as part of their
molecular
formula, enter the following search terms in the Molecular Formula field:
C30 AND H36
Individual elements also support range searching. To search for more than one
element in a range (e.g C14H18 - C14H20) perform separate searches for each
element then combine the hits:
Search 1: C14
Search 2: H18 - H20
Search 3: Combine 1 AND 2
See Range Searching and Combining Hits for more information.
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The Molecular Weight field contains the molecular weight calculated on the basis of molecular formula. The IUPAC published atomic weights of 1997 have been used as a standard. Searches can be made on exact value, range or limit. See also Range searching.
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This field includes all the optical rotation values reported in the entries, and is range searchable.
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This field contains calculated octanol-water partition coefficients for pharmacological agents on the database and is range searchable (see Range Searching).
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Each compound contains an elemental analysis for carbon, hydrogen and nitrogen calculated from the molecular formula. Each is searchable via the fields 'Percent Composition C', 'Percent Composition H' and 'Percent Composition N' in the main compound search screen and can be combined by Linking Fields (see Range Searching).
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Each compound contains an elemental analysis for carbon, hydrogen and nitrogen calculated from the molecular formula. Each is searchable via the fields 'Percent Composition C', 'Percent Composition H' and 'Percent Composition N' in the main compound search screen and can be combined by Linking Fields (see Range Searching).
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Each compound contains an elemental analysis for carbon, hydrogen and nitrogen calculated from the molecular formula. Each is searchable via the fields 'Percent Composition C', 'Percent Composition H' and 'Percent Composition N' in the main compound search screen and can be combined by Linking Fields (see Range Searching).
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A plugin enhances your browser so that you can display and edit chemical structure information, allowing you to search for chemical structures over the web. You must install the plugin in order to conduct a structure search. You can do this from within the dictionary or from the Chemnetbase home page. The plugin is available as both a Windows and Macintosh version.
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To search for a range of values, you can use a hyphen but you must remember to insert a space between hyphen and numbers.
For example, to search the Melting Point field for a melting point within the range of 47 to 51 degrees Celsius, key in 47 - 51 or use the index to select the range. You can use any of the following additional symbols:
greater than
< less than
= greater than or equal to
<= less than or equal to
When range searching, you will retrieve compounds where the recorded melting point falls within the search range, or where the recorded range overlaps with the search range. Thus a search for compounds with a melting point range of 47 to 51 degrees Celsius will retrieve compounds with a recorded melting point of, for example, 45-48 or 51-56 degrees Celsius. Negative numbers are treated in the same manner with the lower number first, e.g. to search for all compounds with a melting point within the range of minus 10 to minus 5 degrees Celsius, enter the following search terms: -10 - -5.
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The Reference field group is searched by selecting the appropriate reference field. The following fields are searchable:
AUTH the surname of the first author
PTEE the patenting company (for patent references)
RTAG the reference tags
TITL the abbreviated title of the journal
VOLN the volume number of the journal
YEAR the year of publication
You must enter the search term exactly as it occurs in the database - click on the Browse Index button to view the index to help you to select the required search term. You can search a specific reference field or a combination of reference fields simultaneously via use of the relevant fields and the Boolean operators. Similarly, Range Searching is possible.
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These are the explanatory notes that are appended to some of the references to indicate the type of information contained in the article, e.g. synth (synthesis), pmr (proton magnetic resonance spectrum). See also Reference Tag Abbreviations.
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This field includes all the refractive index values (quoted to 4 decimal places) reported in the entries and is range searchable. Range searching. See Range Searching.
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This field contains the RTECS® Accession Number(s) reported within an entry. The RTECS® Accession Number refers to the NIOSH Registry of Toxic Effects of Chemical Substances and many entries within The Combined Chemical Dictionary web version contain one or more of these numbers. This data appears towards the end of an entry (or compound) in red type in the form of a seven-digit number preceded by a two-letter code.
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You can search any of the following text and data fields:
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Once you have entered your query, lick on Submit Search in the Search Screen to search the Combined Chemical Dictionary web version using a text and data search, a structure search, or a combination of both.
(see also: Search Fields available , Linking Search Fields)
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You can carry out a structure search on its own, or in combination with a text and data search. NB. In order to conduct a Stucture Search, you need to install the necessary Plugin.
Click on the Draw Query button to display the Structure Drawing screen. For information to assist in preparing your structure query, click on the Help menu in the menu bar at the top of the Structure Drawing screen. This allows you to access the Structure Drawing Help. Once you have prepared your structure query click on the green arrow to transfer your structure to the Compound Search screen.
If you wish to carry out an Exact Search instead of a Substructure Search (the default), select the appropriate radio button. Click on the Submit Search button to initiate the search. Your structure query will be matched against the structures in the current structure file. The number of hits obtained is shown at the top of the screen. See also Examining Search Results.
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This field includes entries that contain compounds which are commercially available from Aldrich, Fluka, Rare Chemicals Library, Sigma and Supelco catalogues plus some other specialist catalogues. The supplier and catalogue numbers are listed. See Supplier Information.
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For a list of contact web addresses for some of the main suppliers named in the Supplier field see below:
For Aldrich, Sigma, Riedel-de Haen, Supelco and Fluka see Sigma-Aldrich
at http://www.sigma-aldrich.com
For Davos, see http://www.davos.com
For Hüls, see Degussa-Hüls AG at http://www.huels.de
For Gelest see http://www.gelest.com
For Acros see http://www.acros.be
For Amoco see BPAmocoChemicals at http://www.bpamocochemicals.com
For Oakwood see http://www.oakwoodchemical.com
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For support on installation or use of the program, please contact:
Technical Support Desk
Electronic Publishing Division
CRC Press LLC
2000 N.W. Corporate Boulevard
Boca Raton, FL 33431, U.S.A.
Tel: 888 318 2367
Tel: 561 998 2562 (Outside U.S.)
Fax: 561 998 9784
E-mail: techsupport@crcpress.com
If your query concerns your system set-up rather than problems with searching the database, please be prepared to supply the following information to the Technical Support Desk staff when you call:
For comments on the data or suggestions for inclusion, please contact:
The Editors, Combined Chemical Dictionary at the address above. Alternatively, email enquiries@crcpress.com stating clearly that your comments are regarding the Combined Chemical Dictionary.
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You can carry out a text and data search on its own, or in combination with a Structure Search. To prepare your text and data search, enter the search terms by using the Browse Index button or typing the terms directly into the Search Terms box. You can enter search terms into as many search fields as you wish (see also Entering search terms, Combining search terms, Search Fields available). When you have entered the search term(s), click on the Submit Search button to carry out the search. See also Examining search results.
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You can use an * as a wildcard to indicate any number of characters when you enter a search term. The * can be used at the beginning of the search term (left-hand truncation), anywhere in the middle, or at the end of the search term (right-hand truncation). For example, if you key in:
BENZO*
as a search term in the Chemical Name field, you will retrieve all compounds whose names start in BENZO, such as: benzoic acid, benzophenone, etc.
If you just want to replace one character as a wildcard, use the ? symbol.
You can also use a combination of * and ? within a search term. For example, if you key in:
PHOSPH?N*
as a search term in the Chemical Name field, you will retrieve entries which include terms starting with PHOSPHIN or PHOSPHON. Entries containing any of the following names will be retrieved:
phosphine
phosphonic acid.
See also Combining Search Terms.
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Use the Type of Compound field to search for specific categories of compounds, using class names for the compounds and the code letters assigned to certain compound classes in the Chapman & Hall/CRC Chemical Database :
Code Letter Compound Class
A Selected General Organics
AC Organophosphorus Compounds
AF Carbohydrates
AH Amino Acids and Peptides
AJ Steroids
B Organometallic Reagents
N Inorganic Structures
P Analytical Reagents
V Natural Products
X Pharmacological Agents
Each subdivision of a class has been assigned a Type of Compound code. These codes appear towards the beginning of an entry (or compound) in the form of the two letters, which identify the compound class, and four numbers. You must enter the search term exactly as it occurs in the database. A list of Type of Compound codes with their definitions can be browsed in the Type of Compound field.
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This field contains all the text associated with the Type of Compound classifications. For example: To search for all flavonoids on the database, enter the search term:
FLAVONOID*
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This field contains all the UV maxima (lmax values) reported in the entries and is range searchable. See Range Searching. The solvent text associated with the lmax values can be searched in the UV Solvent field. The data reported in this field may be followed by the term 'Berdy' or 'DEREP', indicating which database the data was taken from. The absence of either of these terms implies that the data was abstracted direct from the primary literature.
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This is a text field containing the solvent information relating to the UV Maxima (lmax values) of a substance.
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