CH-NMR-NP

Introduction

Journals from which data are compiled

The principles of data inclusion and presentation in the database

Search Methods

Display Results

CH-NMR-NP History

 

Login Page

Link to CH-NMR-NP Login Page For network users only.

Introduction

CH-NMR-NP is a 13C and 1H NMR database of organic natural products compiled from published papers. The building began in May, 2002. The present data are mainly compiled from papers in the following research journals issued from 2001 to the first half of 2005.

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Journals from which data are compiled

  • Chemical and Pharmaceutical Bulletin
  • Journal of Antibiotics
  • Tetrahedron
  • Tetrahedron Letters
  • Journal of Natural Products
  • Magnetic Resonance in Chemistry
  • Journal of Organic Chemistry
  • European Journal of Organic Chemistry

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The principles of data inclusion and presentation in the database

  1. The chemical shift tables of 1H and 13C data are described.
  2. The chemical structure is clearly drawn.
  3. The name and molecular formula (consistent with the chemical structure) are given.
  4. No obvious errors were found in the original literature source.
  5. The compounds were judiciously selected so as not to overlap similar compounds with similar NMR spectra.

As the results, the database does not include every compound that appeared in the above journals in the specified time frame.

The number of the present data set is 12,726(CH-NMR-NP data 11,800 and replicate data from SDBS 926).

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Search Methods

  1. Compounds can be searched by name, molecular formula, molecular weight, and/or NP No.
  2. Wild card search for name and molecular formula is also possible, no additional symbol is required, since by default the search function uses entered name as the stem of all related compounds.
  3. It is also possible to use a search range for numeric data, for example,
    • MW "1500-2000" means to search compounds with molecular weight from 1,500 to 2,000.
    • MW "2000-" means to search compounds with molecular weight 2000 and larger.
  4. To search 13C NMR spectra, input the chemical shifts in ppm. The default range to search around an input chemical shift is 2 ppm (changeable).
  5. To search 1H NMR spectra, input the 1H chemical shifts in ppm. The default range to search around an input chemical shift is 0.2 ppm (changeable).
  6. The search function is case insensitive.
  7. The search logic is "AND"
  8. To start the search, click Search.

The Search Terms

Item for Search Explanation
NP No. The unique NP identification number of the compound.
Search by range is possible.
CAS Registry No. The data are not included. This is future plan.
Compound Name Names of the compound.
Partial input can be used for search.
Capital and small letters are available.
Chemical Formula Wild card search is possible. For example, the input "C30" can search the compounds having carbon number 30.
Molecular Weight The molecular weight (or range) ( numeric )
Substructure Search Chemical structure drawing tool is MarvinSketch available under Java Applet.
Drawing method is similar to popular chemical structure drawing softwares.
Substructure search is performed by JChemTM. MarvinSketch and JChem are the products of Chemaxon Inc.

The Search Results

NP NO NP No. for the compound
Key Spectral Key, Unique key of the NMR data
MF Molecular Formula
MW Molecular Weight
Name Trivial name given by the authors or Chemical name

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Display Results

The table containing NP No., Spectral Key, Molecular formula, Molecular weight, Name of the Compound is displayed for matching compounds by the number given "Search Results" (default 50 and changeable).

By clicking on Key, the Information on the compound, Chemical structure with assignment, 13C and 1H Chemical shifts, 1H Splitting data and the 13C spectrum are displayed.

  • "MF" is molecular formula derived from the chemical structure.
  • "Chemical structure with assignment" is drawn by using an ISIS/Draw. The numbering at the carbon positions corresponds to the 1H and 13C chemical shifts. To obtain 1:1 correspondence between the carbon position and the chemical shift, the different numbers are given for each carbon except for equivalent carbons. When the carbons in a long alkyl chain give the same chemical shifts, the same number may be given. For numbering the carbons, alphabets, Greek characters, or symbols like 1' and 1'' are all converted to figures. The order of the numbering is followed to the authors.
  • "NP Number" is given for an organic natural compound. The same number is given if the spectra were measured by different solvents or different conformers.
  • "CHS" is the spectral key for carbon and proton NMR spectra.
  • "MW" is the molecular formula calculated from the chemical structure by ISIS/Base.
  • "Solvent" is the solvent for the measurement. If the solvent is not described, the data is empty.
  • "Rf (MHz)" is the measuring frequency for 1H NMR spectrum.
  • "Shift Ref" is the chemical shift references for 1H and 13C spectra given by authors. TMS is the internal reference of tetramethylsilane. The solvent shifts for the references are given in ppm unit for "1H / 13C" shifts.
  • "Reference" is the literature from which the data are compiled.
  • "Compound" is taken from the description of the literature to classify the natural compound.
  • "Chem Name" is the full chemical name in the literature.
  • "Remarks" are taken from the authors' description.
  • "Comments" are the compiler's comments.

The 13C spectral pattern is generated from the 13C shifts and the carbon numbers. If other magnetic nuclei such as 19F or 31P are included, the splitting information is not included in the spectral pattern. The intensities of the 13C spectrum are proportional to the relative equivalent carbon numbers. If the 13C shifts of unequivalent carbons are overlapped, the multiplication of the intensities is not made.
Letters "s", "d", "t" and "q" denote C, CH, CH2 and CH3 carbons, respectively. By clicking on the letters, the specification of the carbon types is possible like DEPT.

The 13C spectral pattern is drawn by a JAVA applet and spectral expansion is possible. To return to the original size, the left double click.

The present distribution, by the carbon number, of the organic natural compounds compiled in CH-NMR-NP is shown in the graph below.

 


(click a image for zooming)

 


(click a image for zooming)

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CH-NMR-NP History

Date Revision
June 1, 2004 Service started
June 16, 2004 Public released, Total number of compounds 3,120
June 21, 2004 Added English and Japanese help, etc.
Data addition, Total number of compounds 3,471
July 7, 2004 Changed MF Search reference from the number of C,H,N,O atoms
Added pop-up help of Input Search Conditons Page
August 2, 2004 Added sort function of search results
September 29, 2004 Data addition, Total number of compounds 4,100
February 22, 2005 Data addition, Total number of compounds 5,691
Addition of the selected compounds from SDBS-NMR. The display the measured spectral patterns is possible.
August 2, 2005 Data addition, Total number of compounds 7,426
March 13, 2006 Data addition, Total number of compounds 9,326
October 19, 2007 Data addition, Total number of compounds 12,726

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