1-Fluoro-2,4-dinitrobenzene

1-Fluoro-2,4-dinitrobenzene
IUPAC name

1-fluoro-2,4-dinitrobenzene
Other names

Dinitrofluorobenzene
Identifiers
Abbreviations DNFB
CAS number 70-34-8 Y
PubChem 6264
ChemSpider 21106037 Y
UNII D241E059U6 Y
ChEBI CHEBI:53049 N
ChEMBL CHEMBL167423 N
Jmol-3D images Image 1
Properties
Molecular formula C6H3FN2O4
Molar mass 186.1 g mol−1
Appearance yellow crystals[1]
Density 1.4718 g·cm−3 (54 °C)[2]
Melting point

25.8 °C[2]
Boiling point

296 °C[2]
Hazards
MSDS [1]
EU classification T
 N (verify) (what is: Y/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

1-fluoro-2,4-dinitrobenzene, or Sanger's reagent (commonly called dinitrofluorobenzene or DNFB), is a chemical used for polypeptide sequencing.

Contents

Preparation

In 1936, Gottlieb presented a synthesis in which 1-chloro-2,4-dinitrobenzene reacted with potassium fluoride (KF) in nitrobenzene:[3]

Uses

In 1945, Frederick Sanger described its use for determining the N-terminal amino acid in polypeptide chains, in particular insulin.[4] Sanger's initial results suggested that insulin was a smaller molecule than previously estimated (molecular weight 12,000), and that it consisted of four chains (two ending in glycine and two ending in phenylalanine), with the chains cross-linked by disulfide bonds. Sanger continued work on insulin, using dinitrofluorobenzene in combination with other techniques, eventually resulted in the complete sequence of insulin (consisting of only two chains, with a molecular weight of 6,000).[5]

Following Sanger's initial report of the reagent, the dinitrofluorobenzene method was widely adopted for studying proteins, until it was superseded by other reagents for terminal analysis (e.g., dansyl chloride and later aminopeptidases and carboxypeptidases) and other general methods for sequence determination (e.g., Edman degradation).[5]

Dinitrofluorobenzene reacts with the amine group in amino acids to produce dinitrophenyl-amino acids. These DNP-amino acids are moderately stable under acid hydrolysis conditions that break peptide bonds. The DNP-amino acids can then be recovered, and the identity of those amino acids can be discovered through chromatography.

See also

References

  1. ^ a b Oxford MSDS
  2. ^ a b c CRC Handbook of Chemistry and Physics, 90. edition, CRC Press, Boca Raton, Florida, 2009, ISBN 978-1-4200-9084-0, Section 3, Physical Constants of Organic Compounds, p. 3-260.
  3. ^ Hans Billroth Gottlieb: "The Replacement of Chlorine by Fluorine in Organic Compounds", J. Am. Chem. Soc., 1936, 58 (3), S. 532–533; doi:10.1021/ja01294a502.
  4. ^ Sanger, F (1945). "The free amino groups of insulin". The Biochemical journal 39 (5): 507–15. PMC 1258275. PMID 16747948. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1258275. 
  5. ^ a b Joseph Fruton, Proteins, Enzymes, Genes: The Interplay of Chemistry and Biology. New Haven: Yale University Press, 1999. p. 216.

Literature

External links