ExactMassDB-HR2 Searching

About the Database

HR2, which is one of the fastest tools for calculation of elemental compositions, filters some elemental compositions according to the Seven Golden Rules (Kind and Fiehn, 2007). The ExactMassDB-HR2 (EX-HR2) database returns the same result as does HR2 with kinds and maximum numbers of atoms listed below.


HR2は組成式計算が可能な最も速いツールの一つです。HR2は、Senior則、Lewis則の他、Seven Golder Rules (Kind and Fiehn, 2007)に基づいた候補組成式の絞り込みを 行います。ExactMassDB-HR2 (EX-HR2)は、下記に示す元素およびその上限数で、HR2と同じ絞り込みを適用した組成式候補をデータベース化したものです。

Atom maximum number
C 100
H 200
O 50
N 10
P 10
S 10

Last updated.

Our previous survey demonstrated that 95.65% of the compounds in the Dictionary of Natural Products , 186,788 compounds in the range 50-1500 Da) consist of C, H, O, N, P and S within the ranges C: 1-95, H: 1-182, N: 0-10, O: 1-45, P: 0-6 and S: 0-5 (Iijima et al., 2008). Thus we chose the atom kinds and numbers listed above for construction of EX-HR2. It was estimated that 99.5% of the compounds consisting of C, H, O, N, P and S in KEGG and 99.1% in KNApSAcK were within the criteria. The database would cover most of the natural compounds.

As the exact mass values for the elemental compositions are re-calculated with the atom list we used, they could be different from the original output of HR2.


以前調査した結果では、Dictionary of Natural Productsに含まれるC, H, O, N, P, Sで構成される化合物(186,788化合物、50-1500 Da)のうち、95.65%が、C: 1-95, H: 1-182, N: 0-10, O: 1-45, P: 0-6, S: 0-5の範囲で構成されることが分かりました(Iijima et al., 2008)。そこで、EX-HR2データベースの構築には、これよりも広い原子数設定をしました(上記)。この原子数の範囲は、C, H, O, N, P, Sから構成されるKEGG登録化合物の99.5%、 KNApSAcK登録化合物の99.1%をカバーしていたので、EX-HR2は、ほとんどの天然物の組成式を網羅していると考えられます。


Search Limit: 100

The maximum record number that returns for a single query is 100 as default. The number can be set to a smaller one by setting the "limit" parameter.

When the number of search results exceeds the maximum number, the value of "is-limited" will be set to "true". It means that not all of the search results were written in the returned text, so please be careful to discuss about the results.

The "is-limited" value is written in the returned text when the "output" parameter has been set to "txth" or "xml".




Output Example

Here is a part of results when "txth" is selected for the "output" parameter.



Search Test

# db-name molecular-formula dbe formula-weight id description
EX-HR2 C16H11O2N10P3S1 23.0 500.0000046695
EX-HR2 C19H17O10P1S2   17.0 500.0000767653
EX-HR2 C23H21O1P5S1    23.0 500.0001262922
EX-HR2 C22O6N10        28.0 500.0002278078
EX-HR2 C12H25O7N2P1S5  13.0 500.0002941684
EX-HR2 C13H20O7N4P4S1  14.0 500.0003220237
EX-HR2 C29H10O5P2      28.0 500.0003494305
EX-HR2 C14H14O5N8P2S2  19.0 500.0003836173
db-name EX-HR2
id blank
description blank


Not planned.




-The elemental compositions and their exact mass values registered in the EX-HR2 database.

exhr2.tar.gz (1.43 GB)
# records: 236,633,779
File size: 8.83 GB (after decompression)

-The sample mass list used for the evaluation of EX-HR2.

samplemasslist.zip (175 KB)



exhr2.tar.gz (1.43 GB)
組成式数: 236,633,779
展開後サイズ: 8.83 GB


samplemasslist.zip (175 KB)


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