ChemIDplus A TOXNET DATABASE

ChemIDplus Help

  • This application allows users to search the NLM ChemIDplus database of over 400,000 chemicals. A user may enter compound identifiers such as Chemical Name, Registry Number, Molecular Formula, Classification Code, Locator Code, and Structure or Substructure. Searchable features include search and display by Toxicity indicators such as Median Lethal Dose (LD50), by Physical/Chemical Properties such as LogP, and by Molecular Weight.
    ChemIDplus offers three types of searches:
    The breadcrumbs at the top of most pages allow access to all three types of searches, as well as the TOXNET home page:
    ChemIDplus Breadcrumbs
    This Help page is available from the Help link in the banner:
    ChemIDplus Help on TOXNET Banner
  • The ChemIDplus Lite search page offers a basic search similar to other TOXNET search pages. Just type either the name of a substance or its Registry Number into the search box (e.g. Valium - see Single Result (Lite View)).
    "Starts With" (Right Truncation) searches are available by appending an asterisk (*) at the end of a search term (e.g. val* - see Multiple Results (Lite View)). There must be at least 3 characters before the asterisk.
    Multiple names or registry numbers can be specified in a single search by concatenating them with pipes (|), such as searching for formaldehyde|valium or 50-00-0|439-14-5. Note that a single search can only include names or numbers but not both.

    ChemIDplus Lite search page
  • The Browse ChemIDplus search page allows quick "Starts With" (Right Truncation) searches on the following categories:
    • Name - browse into 1.5 million Names and Synonyms
    • Number - search 850,000 various Registry Numbers and IDs
    • Registry Number - search 370,000 Registry Numbers of the form 50-00-0
    • Superlist ID - search 400,000 ChemIDplus Internal Identifiers
    • UNII - search 43,000 FDA Unique Ingredient Identifiers
    • InChIKey - search 307,000 IUPAC International Chemical Identifier keys generated from structures and searchable on the web
    • Formula - browse into 320,000 molecular formulas
    In the hyperlink/result section below the blue bar, it first indicates the total number of results, for example the screenshot below displays 1,482,980 results for Name. Next it divides those records into groups - one each for every next character that would return a result. Each row includes numbers in parantheses after the link indicating the number of records that start with that term. Where there is only one record in a group, the full matching term is displayed and the link is not followed by a (number).
    For example, the inital set of all Name results below include:
    • 138,426 results for records where name starts with E
    • 9,338 results for records where name starts V
    • 2 results for records where name starts with #
    • only 1 record for each of four results where name starts with one of the following special characters ! * ? {
    ChemIDplus Browse search page
    As result rows are clicked or characters are entered into the Starts With input box, the displayed results are automatically updated. Whenever there is only one record that matches the Starts With term, that record is automatically opened in the Single Result (Full Record View). For example, clicking on any of the four full name records above starting with ! * ? or { would immediately open that record. Similarly, typing any one of those characters in the search box would have the same effect.
    From the screen above, typing V or clicking the V(9,338) row filters the data to just those 9,338 results and again splits out the resulting data by all available next characters. The Results Total line changes to 9,338 results for Name starts with V .... Note that there is only one result that starts with "V0", the V09AB03 hyperlink. Also note that there are 2,793 records that start with "VA".
    ChemIDplus Browse Name starts with V
    Clicking VA(2,793) or adding an A to the search box further filters the data and drills into those records, automatically showing the updated results below. The new data includes the information that there are 1,145 results for names that start with VAL. There is also a new top section with 1 result for Name equals VA. This happens whenever a term exactly matches a result (e.g. search term="VA" and result="VA") while other longer terms only start with the search term.
    ChemIDplus Browse Name starts with VA
    When more than one ChemIDplus record has the same exact value, the hyperlinks will include their Registry Numbers. As an example, this happens when searching on Formula starts with Ni. There are 14 records that include a formula of "Ni".
    ChemIDplus Browse Formula starts with Ni
    The initial results for Registry Numbers, UNIIs, and InChI Keys are below.
    ChemIDplus Browse Registry Numbers ChemIDplus Browse FDA UNIIs ChemIDplus Browse InChI Keys
  • The ChemIDplus Advanced search page is divided into six areas of input. There are individual help topics on each one:
    Each box has an ChemIDplus Heavy info button button to obtain more information, and a reset button ChemIDplus Heavy reset button to clear that section.
    For instance if one were interested in the drug "Valium", one would type that name into the top left search box and press return or click Search. The resulting retrieval is shown in Single Result (Full Record View).
    ChemIDplus Advanced search page
  • For most ChemIDplus searches, a single record is the result and the application automatically opens the Single Result page. For searches with multiple results, there is a link for each result that will open the Single Result page.
    The Lite version of the page:
    • includes the search box which displays the current search and also allows a new search
    • does not display structures
    • includes the following buttons:
      • Full Record - opens a popup window of the Single Result (Full Record View) with detailed information for the record
        (As a popup, it does not include search buttons since further searching should be done from this main browser window.)
      • Other buttons may display on the left based on the record's data - clicking any has the same result as the Full Record button but scrolls the window to the relevant category
      • Search - runs a new search based on the current term displayed in the text box
      • Clear - removes the current term in the text box
      • Main Query Page - navigates to the ChemIDplus Lite Search page
      • Search Results Page - displays when coming from the Multiple Results (Lite View), clicking will navigate back to that page
    In the center of the page, Locators for various resources are hyperlinked by an acronym, with a longer name on the right. The i information button button may be clicked to give more information about a resource. For more detail, see Links to Resources (Locators).
    Here is what would be retrieved for Valium:
    ChemIDplus Lite View record for Valium
  • The Full Record View displays all the ChemIDplus data for a substance, organized by category. The record's details may include a structure, names and synonyms, formulas, notes, classification codes, registry numbers, toxicity and/or chemical/physical property data, and links to other resources.
    Structures on this page are formatted as PNG images for ease of display, and do not require a plug in. Substances with a structure also include an InChI Key generated by that structure, which can be used to search the web for other resources for that structure.
    The Full Record page includes (when available):
    • Buttons and Links:
      • Start New Query - navigates to the ChemIDplus Advanced Search page
      • Modify Query - navigates to the ChemIDplus Advanced Search page and restores the current query criteria
      • Search Results Page - displays when coming from the Multiple Results (Advanced/Structure View), clicking will navigate back to that page
      • Search History - opens a popup window with details on all searches during this browser session, including links to modify or re-run any of them
      • Show Query - opens a popup window with details on the current search criteria
      • Switch to Summary View - immediately loads the Single Result (Summary View) and switches the user's ChemIDplus preference for future results to also default to that summary view
      • Result Structure Search Buttons
      • Links to Resources (Locators)
      • Information ChemIDplus Info button - hovering over or tabbing to any row with this icon opens the Data Sources information panel for that row
      • Category Tabs - the default tab is All which displays data from all categories; click on any other Category Tab to filter the display down to only that category's data instead ChemIDplus Full Record View Tab buttons
      • Wider Results ChemIDplus Wider Results button - switches the category's display to one column of wider results
      • Restore Columns ChemIDplus Restore Columns button - switches the category's display back to 4 columns
    • Summary Section:
      • Preferred Substance Name
      • Preferred Registry Number
      • InChIKey (calculated from the structure)
      • Notes
      • Classification Codes (only when this is a small set that fits in the limited summary space)
      • Molecular Formulas
      • Molecular Weight (calculated from the structure)
      • Structure - a PNG image file
      • When this page is opened with a URL such as http://chem.sis.nlm.nih.gov/chemidplus/name/valium, then the URL Search Term is also included at the top of the summary (this URL format is used by Browse ChemIDplus Search)
    • Tab Section:
      • Classification Codes (when they do not fit above)
      • Links to Resources (Locators)
      • Names and Synonyms
      • Registry Numbers
      • Structure Descriptors
      • Toxicity
      • Physical Properties
    • Per row Data Sources information panel
    Here is what would be retrieved for Valium:
    ChemIDplus Full Record View for Valium
    Hovering over any row with an ChemIDplus Info button button will display the Data Sources infomation panel for that row. Clicking on such a row will pin the panel open. While pinned open, clicking on a different row will update the contents of the panel to the new row's data. In the screenshot below for Valium, first the C16-H13-Cl-N2-O formula's row was clicked on to pin it open, and then the mouse moved over the first classification code "Adjuvants, anesthesia", which updated the indicator text in the bottom right.
    ChemIDplus Full Record View Data Source Panel
    The following shows the result of selecting the Toxicity Category Tab:
    ChemIDplus Full Record View Toxicity Tab
  • By default, ChemIDplus Advanced and Browse ChemIDplus searches open the Single Result (Full Record View) page. Users who prefer to see results in the summary format may click on Switch to Summary View. A cookie is set with the new preference and the Summary View becomes the new default view.
    Structures on this page are formatted as PNG images for ease of display, and do not require a plug in.
    The Summary version of the page includes (when available):
    • Buttons and Links:
      • Switch to Full Record View - immediately loads the Single Result (Full Record View) and switches the user's ChemIDplus preference for future results to also default to that detail view
      • Other buttons may display on the left based on the record's data - clicking any opens a popup window of the Single Result (Full Record View) but scrolls the window to the relevant category
        (As a popup, it does not include search buttons since further searching should be done from this main browser window.)
      • Start New Query - navigates to the ChemIDplus Advanced Search page
      • Modify Query - navigates to the ChemIDplus Advanced Search page and restores the current query criteria
      • Show Query - opens a popup window with details on the current search criteria
      • Search History - opens a popup window with details on all searches during this browser session, including links to modify or re-run any of them
      • Search Results Page - displays when coming from the Multiple Results (Advanced/Structure View), clicking will navigate back to that page
      • Result Structure Search Buttons
    In the center of the page, Locators for various resources are hyperlinked by an acronym, with a longer name on the right. The i information button button may be clicked to give more information about a resource. For more detail, see Links to Resources (Locators).
    Here is what would be retrieved for Valium:
    ChemIDplus Summary View record for Valium
  • Both ChemIDplus Lite and ChemIDplus Advanced searches can match more than one substance. When this happens, the Multiple Results screen is displayed. For each result displayed on a page, clicking on its hyperlink opens the individual record.
    The Lite version of this page:
    • is loaded by default for any ChemIDplus Lite search that returns multiple results
    • includes the search box which displays the current search and also allows a new search
    • includes a hyperlink for each record; these all open the Single Result (Lite View) page
    • does not display structures, allowing the page to load faster and for rows to take less space
    • includes the following buttons:
      • Main Query Page - navigates to the ChemIDplus Lite Search page
      • Next Page - navigates through the results to the next subset
      • Previous Page - navigates through the results to the prior subset
      • Go To Record Number - prompts for a records number, and then navigates through the results to the subset including that particular record number
      • Advanced View (structures) - displays the same subset of results in the Multiple Results (Advanced/Structure View) instead
      • Search - runs a new search based on the current term displayed in the text box
      • Clear - removes the current term in the text box
    ChemIDplus Lite Multiple Results
  • The Advanced/Structure version of this page:
    • is loaded by default for any ChemIDplus Advanced search that returns multiple results
    • includes a hyperlink for each record; these all open the Single Result (Full Record View) page
    • displays structures and structure search buttons
    • includes the following buttons:
      • Start New Query - navigates to the ChemIDplus Advanced Search page
      • Modify Query - navigates to the ChemIDplus Advanced Search page and restores the current query criteria
      • Show Query - opens a popup window with details on the current search criteria
      • Search History - opens a popup window with details on all searches during this browser session, including links to modify or re-run any of them
      • Go To Record Number - prompts for a records number, and then navigates through the results to the subset including that particular record number
      • Lite View (no structures) - displays the same subset of results in the Multiple Results (Lite View) instead
      • Next Page - navigates through the results to the next subset
      • Previous Page - navigates through the results to the prior subset
      • Result Structure Search Buttons
    ChemIDplus Advanced Multiple Results
  • Chemical names are often hard to spell and tend to be phoneticized by users into an incorrect name. If you had mistakenly input the name of "valeum", the system would not have been able to find an exact match. The system would then have tried to find some near matches for you. As you can see, in this case this includes the correct "valium" name.
    Click on one of these names to go to the appropriate record.
    Or to modify your search, in the Lite version, update the value in the search box and click Search.
    ChemIDplus Lite Spell Check
    While for the Advanced version, the query page link navigates to the ChemIDplus Advanced Search page and restores the current query criteria
    ChemIDplus Advanced Spell Check
  • There are three types of Locators:
    • File Locator(s) that point to a set of NLM associated databases of interest
    • Internet Locator(s) that point to a set of external resources with biomedical data that are relevant for this chemical, and
    • Superlist Locator(s) that point to a set of regulatory and scientific lists that contain information about this chemical.
    Clicking on the Locator hyperlink will open a new window with data from a given resource, as close to the level of the substance as possible. An example for the File Locator HSDB (Hazardous Substances Databank) follows:
    ChemIDplus Summary View Locator
    Each Locator hyperlink opens a new browser window to the external resource's website, HSDB in this case. Further navigation within this new browser window is as normal (e.g. for this HSDB record, clicking on its left hand menu).
  • The following ChemIDplus Advanced result pages include structure images with structure buttons alongside each image:
    Hovering over or tabbing to the structure buttons expands the button to show the label. These are the structure buttons with their functions:
    ChemIDplus Advanced Transfer Structure to Query Page button Transfer structure to query page copies the structure to the ChemIDplus Advanced Search page's Structure Search section to allow custom searches based on this structure.
    ChemIDplus Advanced Find Similar Structures button Find similar structures searches for compounds whose structures are 80% similar to the current compound (see Similarity Search in Structure Search Options).
    ChemIDplus Advanced Find Parent, Salts, and Hydrates button Find parent, salts, and hydrates searches for compounds whose structures contain the current compound (see Flex (parent, salts, mixture) in Structure Search Options).
    ChemIDplus Advanced Enlarge the Structure button Enlarge the structure opens a Marvin for Javascript editor window where the structure can be expanded to any magnification.
    ChemIDplus Advanced View 3D Structure button View 3D structure opens a JSmol window where the 3D structure can be viewed and rotated.
  • The top left section in the ChemIDplus Advanced Search page is Substance Identification. It contains two pull down selects and an input box.
    ChemIDplus Advanced Name Search Results
    The first select box allows searching on the following categories:
    • Name/Synonym - search 1.5 million Names and Synonyms
    • Registry Number - search 850,000 various Registry Numbers and IDs
    • Formula (hyphenated) - search 320,000 molecular formulas
    • Classification Code - category data
    • Locator Code - filter results based on whether records exist in other databases
    The second select box allows specifying the operator:
    • Equals - search results will match the term specified, unless a final asterisk is used, making this function as Starts with
    • Starts with - search results will include data where the beginning of the data matches the search term specified
    • Contains - takes longer than Starts with but matches data where the search term is found anywhere inside the data
    If you select the Starts with operator from the second pull down and click Search, the system will search for all names that start with that name or fragment of a name. As the beginning of the systematic name of Valium is "2H-1,4-Benzodiaz", running the search "Name/Synonym" "Starts with" "2H-1,4-Benzodiaz" (displayed above) retrieves 241 answers that fit these criteria, including Diazepam [USAN:USP:INN:BAN:JAN] (Valium), and display them as follows in the Multiple Results (Advanced/Structure View):
    ChemIDplus Advanced Name Search Results
    You may then select one or more records of interest to you of the 241 retrieved. Each compound contains a name that starts with 2H-1,4-Benzodiaz, even though this may not be the name shown on the retrieval screen. You may also achieve truncation by appending an asterisk to a string as in ChemIDplus Lite. Thus the string 2H-1,4-Benzodiaz* used in the Name/Synonym Equals setting would also search for right truncation.
    You could also use the Contains operator after a name or name fragment. This search takes longer, but would find embedded instances of that input string.
    Selecting the Registry Number option searches across several Registry Number fields in the ChemIDplus database. Entering the Registry number of Valium, "439-14-5" and using the "Registry Number" category would retrieve the Valium record just as the name did. The 10 character long (zero filled), non-hyphenated form of "000439145" would also work. The Registry Number search also retrieves from superseded RNs under Other Registry Numbers and Related Registry Numbers.
    The Classification Code field contains category data from several sources for a given chemical. To search it, select the Classification Code option, enter a search term, and hit enter. For instance, a search for "antineoplastic agents", a MeSH term carried in the Classification Code field, gives the following results:
    ChemIDplus Advanced Classification Code Search Results
    The Molecular Formula field contains the molecular formula of compounds, that is, a summary of the types of atoms contained it the structure and their counts. They are stored or searched in the HILL convention (carbon, hydrogen first then all other elements alphabetically). ChemIDplus also uses hyphens between elements and their counts. To search this field, pull down the Formula (hyphenated) option and enter the formula desired. A molecular formula is not a unique piece of data, so you may get multiple results from a search. Here is the result for the formula of TCDD (C12-H4-Cl4-O2):
    ChemIDplus Advanced Formula Search Results
  • ChemIDplus contains a table of toxicity values for search and display. A user may search individually on values and ranges throughout this data, and use it to qualify other searches. In most cases, a lower dose in mg/kg in a given test regimen means more toxicity in this regimen for this chemical. This data comes from an older subset of the RTECS database from NIOSH. Here are some of the basic definitions:

    Toxicity Terms *
    Note: These abbreviations indicate whether the dose caused death (LD) or other toxic non-lethal effect (TD), or whether it was administered as a lethal concentration (LC) or toxic concentration (TC) in the inhaled air. In general, the term “Lo” is used where the number of subjects studied was not a significant number from the population or the calculated percentage of subjects showing an effect was 100. The doses and concentrations are defined as follows:
    • TDLo – Toxic Dose Low – the lowest dose of a substance introduced by any route, other than inhalation, over any given period of time and reported to produce any toxic effect in humans or to produce tumorigenic, reproductive, or multiple dose effects in animals.
    • TCLo – Toxic Concentration Low – the lowest concentration of a substance in air to which humans or animals have been exposed for any given period of time that has produced any toxic effect in humans or caused death in humans or animals.
    • LDLo – Lethal Dose Low – the lowest dose (other than LD50) of a substance introduced by any route, other than inhalation, over any given period of time in one or more divided portions and reported to have caused death in humans or animals.
    • LD50 – Lethal Dose Fifty – a calculated dose of a substance which is expected to cause the death of 50% of an entire defined experimental animal population. It is determined from the exposure to the substance by any route other than inhalation of a significant number from that population. Other lethal dose percentages, such as LD1, LD10, LD30, and LD99, may be published in the scientific literature for the specific purposes of the author. Such data would be published in the Registry if these figures, in the absence of a calculated lethal dose (LD50), were the lowest found in the literature.
    • LCLo – Lethal Concentration Low – the lowest concentration of a substance in air, other than LC50, which has been reported to have caused death in humans or animals. The reported concentrations may be entered for periods of exposure that are less than 24 hours (acute) or greater than 24 hours (substance and chronic).
    • LC50 – Lethal Concentration Fifty – a calculated concentration of substance in air, exposure to which for a specified length of time is expected to cause the death of 50% of an entire defined experimental animal population. It is determined from the exposure to the substance of a significant number from that population.
    *Source: US Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health. (1997). Comprehensive guide to the registry of toxic effects of chemical substances. DHHS (NIOSH) Publication No. 97-119.
    Table 1. Test Results
    Lethality Extreme High Moderate Low
    Oral LD50 <50 mg/kg 50-500 mg/kg 500-5,000 mg/kg >5,000 mg/kg
    Dermal LD50 <200 mg/kg 200-2,000 mg/kg 2000-20,000 mg/kg >20,000 mg/kg
    Inhalation LC50 <200 mg/m3 200-2,000 mg/m3 2,000-20,000 mg/m3 >20,000 mg/m3
    Source: U.S. EPA. Office of Pesticide Programs, Registration and Classification Procedures, Part II. Federal Register 40:28279.
    Numerical Toxicity Rating Definitions*(Human Oral Lethal Dose)Toxicity Rating or Class Dose for 70 kg. Person (150lb.)
     6  Supertoxic  < 5 mg./kg.  A taste (less than 7 drops)
     5  Extremely toxic  5-50 mg./kg.  Between 7 drops and 1 tsp.
     4  Very toxic  50-500 mg./kg.  Between 1 tsp. And 1 oz.
     3  Moderately toxic  0.5-5 gm./kg.  Between 1oz. and 1 pint (1lb.)
     2  Slightly toxic  5-15 gm./kg.  Between 1 pint and 1 quart
     1  Practically nontoxic  Above 15 gm./kg.  More than 1 quart (2.2 lb)
    *Source: Gosselin, Robert E., Smith, Roger P., & Hodge, Harold C. (1984). Clinical toxicology of commercial products. Fifth Edition. Baltimore: Williams & Wilkins.
    There has been some effort at international harmonization of the meaning of LD50 values. Here is a reference to one publication: http://www.unece.org/trans/danger/publi/ghs/ghs_text-pdf/GHS-PART-3e.pdf
    The user may range over the values of these tests in combination with other parts of a search. Note that the actual count of each Test is given in parentheses for guidance. Here is a search for LD50 Values in Mice given Intraperitoneally, with values between 0 and 30:
    ChemIDplus Advanced Toxicity Search
    Of over 3,500 results retrieved and displayed in the Multiple Results (Advanced/Structure View), selecting the first answer navigates to the Single Result (Full Record View) for the chemical Mitomycin C, and then selecting the Toxicity tab displays the image below. Note that a reference line which meets ANY criteria has that value highlighted in red. Any line that meets ALL criteria is highlighted in yellow. Some references contain a link to a Medline citation, if available.
    ChemIDplus Advanced Toxicity Search Result
  • ChemIDplus contains searchable Physical Property data for over 25,000 compounds. Some values have been measured and some calculated. Here are definitions for these values:
    • MELTING POINT
      • The temperature at which the solid and liquid phases are in equilibrium at one atmosphere (Boethling, 2000)
      • Used for estimating vapor pressure when the chemical is a solid (Boethling, 2000)
    • BOILING POINT
      • The temperature at which a liquid’s vapor pressure equals the pressure of the atmosphere of the liquid. (Boethling, 2000)
      • Pure chemicals have a unique boiling point which can be used in identification of material. (Boethling, 2000)
      • Used for estimating vapor pressure (Boethling, 2000)
    • WATER SOLUBILITY
      • Affects chemical's distribution between environmental compartments
      • if LOW: Dissolve more slowly and have a stronger tendency to partition out of aqueous solution into other phases (suspended solids and sediment) . (Boethling, 2000)
      • if HIGH: Dissolve freely in water if accidentally spilled and will tend to remain in aqueous solution until degraded. (Boethling, 2000)
      • There is a relationship between Water solubility and the ability to biodegrade.
    • OCTANOL/WATER PARTITION COEFFICIENT
      • Mimics partitioning in biota
      • Ratio of concn of a solute between water and octanol (Boethling, 2000)
      • Used for estimating soil adsorption, bioconcentration, Henry’s Law constant (air/water partition coefficient)
      • log Koc = 0.903 log Kow + 0.094 (Boethling, 2000)
      • Used for estimating bioconcentration, bioaccumulation, and bioavailability
      • log BCF = 0.79 log Kow -0.4 (64FR604)
      • PBT Criteria: BCF values of 100 to 1,000 medium concern; >1,000 high concern (EPA). (64FR604)
      • Other High Concern Values: BCF of 5000 ( NAFTA-CEC); BCF of 5,000 (UNECE-LRTRAP); BCF of 5,000 (CMA) (64FR604)
    • VAPOR PRESSURE
      • Affects whether a chemical in the atmosphere will occur as a vapor or adsorbed to particulate matter.
      • Physical State of Compound: (Bidleman, 1988)
      • "</=" 10-8 mm Hg Solely in Particulate Phase
      • 10 5, 10 6, 10 7 mm Hg Vapor and Particulate Phases
      • ">/=" 10 4 mm Hg Solely in Vapor Phase
    • ACID DISSOCIATION CONSTANT
      • Indicates whether a chemical is undissociated or occurs as an anion ("acid") or cation ("base").
      • Values of pKa<4 for bases and pKa>8 for acids are not relevant in an environmental context. (Tomlin, 1997)
    • HENRY’'S LAW CONSTANT
      • Ratio of a chemical's concentration in the gas phase to that in the liquid phase
      • Volatilization from moist soil and water surfaces: (Lyman et al 1990)
      • <10-7 atm m3/mole Essentially non-volatile
      • 10-7 to 10-3 atm m3/mole May volatilize
      • >10-3 atm m3/mole Will volatilize rapidly
      • Atmospheric removal of particulate-phase compounds: (Lyman et al 1990)
      • Wet deposition: removal from atmosphere by precipitation of rain, fog, snow
      • Dry deposition: removal from atmosphere of particle associated chemical by diffusion/ sedimentation
    • OH RADICAL REACTION RATE CONSTANT
      • The OH radical is the key reactive species in the troposphere. All organics react with OH except CFCs and non-hydrogenated Halogens (Boethling, 2000)
      • Used to calculate the half-life of chemicals in the atmosphere (Boethling, 2000)
      • PBT Criteria: Persistence half-life in air = 2 days. (64FR604)
    • REFERENCES:
      • 64FR608. Federal Register. Persistent Bioaccumulative Toxic (PBT) Chemicals; Proposed Rule. January 5, 2002.
      • Bidleman, T.F. Atmospheric processes. Wet and dry deposition of organic compounds are controlled by their vapor particle partitioning. Environ Sci Technol 22: 361-367 (1988)
      • Boethling R.S., and D. Mackay. Handbook of Chemical Property Estimation Methods. Boca Raton, FL: Lewis (2000)
      • Lyman, W.J., et al. Handbook of Chemical Property Estimation Methods. Washington, DC: Amer Chem Soc (1990)
      • Tomlin, C.D.S. (ed.). The Pesticide Manual World Compendium. 11th ed., Surrey, England: British Crop Protection Council. (1997)
    Following is a search for compounds with a LogP greater than 5, that is the chemical partitions into fat at a 105 higher concentration than water:
    ChemIDplus Advanced LogP Search
    The results of that search are below. Note that DDT is retrieved, a substance which is known to be stored in the fatty tissues of animals. Also Thioridazine, which is an Antipsychotic agent with Central Nervous System (CNS) activity often associated with lipid solubility:
    ChemIDplus Advanced LogP Search Results
    For some ranges of small values such as those found in Henry's law, the exponential input format may be used. Thus to find the range shown in the Help of 10-3 to 10-7 (may volatilize), the following input format is appropriate:
    ChemIDplus Henry's Law Search
  • This field allows qualification of a search by the presence of data in a given resource. This can be entered free form in the Substance Identification Search section using the Locator Code option, or in the Locator Codes section on the bottom of the page. This qualification can be used with any other search box as a limiter. For Locators entered in this section, a user may specify AND, OR, or AND NOT logic for any two locators. Thus the following search would find compounds in CCRIS which are not in HSDB:
    ChemIDplus Advanced Locator Search
    This retrieves over 6,000 records which are in the CCRIS file and are not in the HSDB file, and displays them in the Multiple Results (Advanced/Structure View).
  • ChemIDplus offers multiple methods to get a structure ready to search with:
    • To transfer an existing structure, see Result Structure Search Buttons.
    • An MDL Molfile can be imported from the user's computer using the Import MOL button.
    • To draw a structure, click the Draw button. Users may use either the fast default Marvin for Javascript editor or the slower but more advanced Marvin Java applet. Note, to use the Marvin Java applet, your browser must have the latest version of the Java Virtual Machine installed and enabled, whereas Marvin for Javascript runs in any HTML5-capable browser without a plugin. For IE, version 9 or above is needed for Marvin for JavaScript due to use of HTML5. For users with IE8 or less, Marvin applets automatically load instead. Chime is not readily available and is no longer supported.
    • To edit a structure, click the structure's image or the Edit button.
    • To display an imported, drawn, or edited structure in 3D, switch “Use” from “Marvin for JavaScript” to “Marvin applets incl. 3D”. After the applet loads, open the applet's View menu and select “Open Marvin Space” or “Open MarvinView3D”.
    Using the tools provided by Marvin for Javascript, a simple structure can quickly be made:
    ChemIDplus Advanced Marvin for Javascript Editor
    Once the drawn or edited structure is correct, clicking Use this structure updates the search page with the new structure:
    ChemIDplus Advanced Marvin for Javascript Search
    Once the structure has been selected, imported, drawn, and/or edited and is ready, users may then choose one of the Structure Search Options.
    • Substructure Search, which will look for the drawn (or transferred) structure embedded in the structures of other compounds. This is useful for finding a set of compounds that share a common "Sub Structure" which may cause good or bad biological activity. An example would be the organophosphate class of pesticides which can be represented by a substructure. Remember, Marvin and ISISDraw both allow indeterminate atoms to be used in substructures.
    • Similarity Search, which will look for other compounds with structural features that are similar to the those of the drawn (or transferred) structure. The default is to find compounds that are 80% similar. This similarity percentage may be changed to be between 50% and 100% in the pull down box. You many find compounds that are related and are relatively close in overall size using this method. For Instance the structure of the drug "Rabeprazole" is 91% similar to the drug "Omeprazole", which has similar anti ulcer activity. In other cases retrieved compounds may share features but arrange these structural features differently than the parent and thus give different biological activity.
    • Exact (parent only), which will look for the structure that is drawn (or transferred) as a complete entity, with all the structure's atoms and bonds identical in the retrieved compound.
    • Flex (parent, salts, mixture), which will look for the structure that is drawn (or transferred), with all bonds identical in the retrieved compound including stereochemical and tautomeric bonds. Flex will also find salts, mixtures, hydrates, and polymers of the parent that is drawn. A Flex search of the structure of Penicillin G will find 28 salts and mixtures including Penicillin G Potassium. If you start with a complex salt or mixture with two or more components, you may only retrieve salts and mixtures that have two or more components. The substance "Clopidogrel bisulfate" will not retrieve the parent "Clopidogrel" in this mode, while the structure of the simpler compound named "Chlordiazepoxide hydrochloride" will find the parent "Chlordiazepoxide" in Flex mode. SUGGESTION: If your input structure has more than two or more components, delete all components but the structure you are interested in before using Flex.
    • Flexplus (parent, all variations), which will look for the structure that is drawn (or transferred), including compounds that have stereochemical and tautomeric variations in their bonds. It will also find salts, mixtures, hydrates, and polymers of the parent that is drawn, plus compounds containing metal atoms bonded to the parent. Flexplus may find compounds with different biological activity from the parent because of differences in stereochemistry and metal bonding. For instance a search for the structure of "Adenine arabinoside" (Vidarabine), which is an antiviral, will retrieve the record for "Adenine riboside" (Adenosine) which has no such activity. You should use Flexplus with caution if this possibility is a problem for you, and perhaps use Flex instead. SUGGESTION: If your input structure has more than one component, delete all components but the structure you are interested in before using Flexplus.
  • For every structure in ChemIDplus, a molecular weight (MW) is calculated and stored. The user should be aware that because of differing drawing conventions, this calculated value may differ from the true MW. For instance, if a salt with a ratio of two organic ions to one inorganic ions is drawn, the MW will sum the weights of both organic ions, effectively doubling the MW. The user may range over two values (preferred method), or use the greater than, less than, or equals operator. Here is an example of a query to find MWs between 190 and 200. Note that the results show the calculated MW on each record.
    ChemIDplus Advanced Molecular Weight Search
    Here are the results of this search:
    ChemIDplus Advanced Molecular Weight Search Results
  • A user may combine query terms from any of the fields in a search. The query term(s) from each section are ANDed together to get a resultant set of answers. Thus a query for compounds with a mouse LD50 less than 100 given interperitoneally with the substructure of pyridine and with data contained in the HSDB file is input as follows:
    ChemIDplus Advanced Multiple Terms Search
    It gives the following 42 results:
    ChemIDplus Advanced Multiple Terms Search Results
    When searching multiple types of data, remember that compounds for which ChemIDplus does not have data in a given area will not be retrieved since all requested field values are required. This is especially important in Physical Properties, which occurs in the least number of records. The query logic can be reviewed by clicking on either the Show Query or Search History buttons. The latter allows all searches with results counts and the ability to rerun them exactly, or modify them.
    ChemIDplus Advanced Multiple Terms History
If you have any comments please send us email at tehip@teh.nlm.nih.gov, or the following customer service number.