Folin-Ciocalteu reagent

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Standard range of tyrosine

The Folin-Ciocalteu reagent (FCR) is a solution of molybdophosphoric acid and tungstophosphoric acid . It is not identical to the Folin reagent . A publication on the Lowry test using the Folin-Ciocalteu reagent from 1951 with the title Protein measurement with the Folin phenol reagent was the most frequently cited article between 1945 and 2014 with 305,148 citations.

properties

The Folin-Ciocalteu reagent is used for the colorimetric determination of phenolic and polyphenolic antioxidants . However, the total phenols cannot be specifically measured with this reagent, as it also reacts with other reducing substances. Therefore, the total antioxidant capacity of the sample is determined, not just the proportion of phenolic components. It also reacts with the nitrogen from hydroxylamine and guanidine . Copper ions intensify the reaction. The determination takes place at a wavelength of 660 nm.

use

The Folin-Ciocalteu reagent is used, among other things, for the Lowry test and to determine tyrosine .

It was also used to determine the amount of reducing compounds (including antioxidants ) in foods , in addition to the Oxygen Radical Absorbance Capacity and the Trolox Equivalent Antioxidant Capacity . The United States Department of Agriculture (USDA) found in 2012 that there was no evidence of the free radical theory and the measurement was therefore irrelevant.

history

It is named after its developers Otto Folin and Vintilă Ciocâlteu , who presented it in 1927 in an article on the determination of tyrosine and tryptophan in proteins. This solution was based on the 1915 Folin-Denis reagent made from tungstate and molybdate in phosphoric acid, which Folin developed with Willey Glover Denis .

Individual evidence

  1. ↑ Oliver H. Lowry, Nira J. Rosebrough, A. Lewis Farr, and Rose J. Randall: Protein Measurement with the Folin Phenol Reagent . In: Journal of Biological Chemistry . 193, No. 1, 1951, pp. 265-275. PMID 14907713 .
  2. ^ Richard Van Noorden, Brendan Maher, Regina Nuzzo: The top 100 papers. In: Nature. 514, 2014, pp. 550-553, doi : 10.1038 / 514550a .
  3. ↑ Vernon L. Singleton, Rudolf Orthofer, Rosa M. Lamuela-Raventós: Analysis of total phenols and other oxidation substrates and antioxidants by means of folin-ciocalteu reagent . In: Methods in Enzymology . tape 299 , 1999, pp. 152-178 , doi : 10.1016 / S0076-6879 (99) 99017-1 .
  4. ↑ M. Ikawa, TD Schaper, CA Dollard, JJ Sasner: Utilization of Folin-Ciocalteu phenol reagent for the detection of certain nitrogen compounds. In: Journal of agricultural and food chemistry. Volume 51, Number 7, March 2003, pp. 1811-1815, doi : 10.1021 / jf021099r , PMID 12643635 .
  5. ↑ JD Everette, QM Bryant, AM Green, YA Abbey, GW Wangila, RB Walker: Thorough study of reactivity of various compound classes toward the Folin-Ciocalteu reagent. In: Journal of agricultural and food chemistry. Volume 58, number 14, July 2010, pp. 8139-8144, doi : 10.1021 / jf1005935 , PMID 20583841 , PMC 4075968 (free full text).
  6. ↑ KI Berker, FA Ozdemir Olgun, D. Ozyurt, B. Demirata, R. Apak: Modified Folin-Ciocalteu antioxidant capacity assay for measuring lipophilic antioxidants. In: Journal of agricultural and food chemistry. Volume 61, Number 20, May 2013, pp. 4783-4791, doi : 10.1021 / jf400249k , PMID 23627440 .
  7. ↑ B. Ou, M. Hampsch-Woodill, RL Prior: Development and validation of an improved oxygen radical absorbance capacity assay using fluorescein as the fluorescent probe. In: Journal of agricultural and food chemistry. Volume 49, Number 10, October 2001, pp. 4619-4626, PMID 11599998 .
  8. ↑ X. Wu, GR Beecher, JM Holden, DB Haytowitz, SE Gebhardt, RL Prior: Lipophilic and hydrophilic antioxidant capacities of common foods in the United States. In: Journal of agricultural and food chemistry. Volume 52, Number 12, June 2004, pp. 4026-4037, doi : 10.1021 / jf049696w , PMID 15186133 .
  9. ^ G. Cao, HM Alessio, RG Cutler: Oxygen-radical absorbance capacity assay for antioxidants. In: Free radical biology & medicine. Volume 14, Number 3, March 1993, pp. 303-311, PMID 8458588 .
  10. ↑ RL Prior, X. Wu, K. Schaich: Standardized methods for the determination of antioxidant capacity and phenolics in foods and dietary supplements. In: Journal of agricultural and food chemistry. Volume 53, Number 10, May 2005, pp. 4290-4302, doi : 10.1021 / jf0502698 , PMID 15884874 .
  11. ↑ Withdrawn: Oxygen Radical Absorbance Capacity (ORAC) of Selected Foods, Release 2 (2010) . United States Department of Agriculture, Agricultural Research Service. May 16, 2012. Retrieved June 13, 2012.
  12. ↑ Folin, O., and Ciocalteu, V .: On tyrosine and tryptophane determinations in proteins . In: Journal of Biological Chemistry . 73, 1927, p. 627.
  13. ↑ Wilfred Vermerris: Phenolic Compound Biochemistry. Springer Science & Business Media, 2007, ISBN 978-1-402-05164-7 , p. 152.