Biological Magnetic Resonance Data Bank

A Repository for Data from NMR Spectroscopy on Proteins, Peptides, Nucleic Acids, and other Biomolecules
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Heuristically Determined Formula by Mass

This page is meant to be a tool for mass spectrometry. The formula masses for over 400 million formulas have been calculated and stored. Because of the large combinatorial problem, formulas with natural abundance masses less than 2000 daltons were calculated and heuristic rules were used to limit the formulas to those that are most likely to be found in nature.

Please take a moment to review the input formats.

Because of the large file sizes and http post constraints, limit your query list to 500 entries or less. Very large files do not get transferred.

Isotopic Labeling
None 13C 15N 13C and 15N
Mass distribution:
ppm dalton
Mass list type:
Just Mass Index RT Mass
Query by:
uploading a file with a list of query values:

Query by:
Entering one or more values to query:

The results of your query will be deposited into a downloadable, tab seperated file and posted below. Please be aware that large queries may take some time to complete.