Fluoroacetate analysis

Fluoroacetate and 4-fluorothreonine are synthesized from fluoride by Streptomyces cat-tleya, and analysis of supernatants was used to elucidate the details of their biosynthesis. They were apparently synthesized by independent routes, and it was suggested that what is formally glycolate could be their precursor (Reid et al. 1995). 

Other applications dealt with the development of a luciferin ester substrate to measure the luciferase activity in living cells [141], the detection of toxic compounds such as sodium azide, fluoroacetic acid, and antibiotics [142], the development of a biosensor for the determination of bioavailable mercury [143], the use of eukaryotic luciferases as bacterial markers with different colors of luminescence [144], the determination of complement-mediated killing of bacteria [145], and the development of a bioassay for the determination of HIV type 1 virus and HIV-1 Tat protein activity, valuable also for analysis of HlV-inhibi-tory agents [146],... 

Okuno, I., G.E. Connolly, P.J. Savarie, and C.P. Breidenstein. 1984. Gas chromatographic analysis of coyote and magpie tissues for residues of compound 1080 (sodium fluoroacetate). Jour. Assoc. Offic. Anal. Chem. 67 549-553. 

Derivative formation prior to chromatographic analysis has been used successfully. An unidentified component of urine was found which had a retention time very close to that of pregnanediol and which could not be separated from it by thin layer chromatography. The trimethylsilyl ether derivatives and the tri-fluoroacetate derivatives of the two compounds would not provide resolution only the acetate derivatives could be separated. 

O Hagan D, Goss RJM, Meddour A, Courtieu J (2003) Assay for the Enantiomeric Analysis of I HJ-Fluoroacetic Acid Insight in the Stereochemical Course of Fluorination During Fluorometabolite Biosynthesis in Streptomyces cattleya. J Am Chem Soc 125 379... 

Sporkert, F., Pragst, F., Huebner, S., Mills, G.G. (2002). Head-space solid-phase microextraction with 1-pyrenyldiazo-methane on-fibre derivatisation for analysis of fluoroacetic acid in biological samples. J. Chromatogr. B 772 45-51. 

Figure 1.30 Catabolic pathway of capecitabine from 19F NMR analysis of patients urine. All the compounds are represented in neutral form. CAP, capecitabine 5 dFCR, 5 -deoxy-5-fluorocytidine FC, 5-fluorocytosine OHFC, hydroxy-5-fluorocytosine 5 dFUR, 5 -deoxy-5-fluorouridine FU, 5-fluorouracil FUH2/ 5,6-dihydro-5-fluorouracil FUPA, a-fluoro-fi-ureidopropionic acid FBAL, u-fluoro-fi-alanine I, fluoride ion FHPA, 2-fluoro-3-hydroxypropanoic acid FAC, fluoroacetic acid. Metabolites identified for the first time in urine of patients with 19F NMR are represented in ellipses.

A detailed study of the photoelimination reactions of the racemic tri-fluoroacetates (59, 60) has been reported by Gano and Chien. A kinetic analysis... 

Although amines do not have to be in the free-base form for acylation by perfluoroacyl anhydrides, and derivatize smoothly even as their salts, some workers have included bases for catalytic purposes, and also to remove acid formed during the reaction, in addition to a solvent. In one recipe, the amine is dissolved in benzene (500 y ) and trimethylamine is added (100 fi of a 0.05 M solution in benzene) followed by 10 1 of anhydride, and the reaction is allowed to go to completion at room temperature. With the low concentration of anhydride this may take some hours. Excess anhydride is removed by washing with 3M ammonium hydroxide and the benzene solution is dried before GC analysis (80, 81]. In a similar procedure, the rather uncommon chlorodi-fluoroacetic anhydride is used. Here the base, extracted from its biological matrix, is dissolved in chloroform (20 fi ) and derivatized with triethylamine (1.5 yl) and the anhydride (3 y ) at 50 °C for 30 min. Excess reagent is neutralized with alkali and the derivatives are concentrated to dryness and taken up in toluene for GC analysis [82]. Trichothecenes (250 mg) are treated with TFAA and about 10 mg of solid sodium bicarbonate for 30 minutes at 80 C [83]. Alternatively, 0.5 ml of 10% acetonitrile in toluene is added followed by 100 y of triethylamine and 100 ul of PFPA. The reaction is carried out at 60 C for 15 minutes, and the reaction solution is washed with two 0.5 ml portions of 5% aqueous ammonia and one 0.4 ml portion of water to remove the surplus reagents [84]. 

Gravimetric analysis is a technique in which the mass of a substance in a mixture is determined. A mixture containing no fluorine compound except methyl fluoroacetate, FCHjCOOCHg (MFA), yields 12.1 mg CaFj. Find the mass of MFA in the mixture,... 

Nakayama, T., Kamachi, T., Jitsumori, K., et al., 2012. Substrate specificity of fluoroacetate dehalogenase an insight from crystallographic analysis, fluorescence spectroscopy, and theoretical computations. Chemistry 18 (27), 8392-8402. 

Vickery, B., Vickery, M.L., Ashu, J.T, 1973. Analysis of plants for fluoroacetic acid. Phytochemistry 12, 145-147. 

Figure 5. Anlytical HPLC separation of 300 pg venom peptides (A) and 10 ml conditioned water (B) from Conus textile. Details on preparation of the substances are given in the legend to Fig. 4. Separations were performed on an analytical CIS reverse phase column (Vydac wide pore, 4.6 x 250 mm, 5 pm particle size) at a flow rate of 0.5 ml/min. Substances were loaded on the column in aqueous 0.1% tri-fluoroacetic acid (TFA) and eluted with a linear gradient of 0-60% acetonitrile in 0.1% aqueous TFA in 0-60 minutes. On-line detection and spectral analysis was performed with a Hewlett-Packard diode array detector. The spectrum of the main peak obtained from the CW (B) is not identical to those of any of the venom derived peptides (A) that are eluted at similar times from the column (not shown). Attempts to isolate the active component(s) of Conus textile CW on reverse phase cartridge columns and Amicon filters were not successful, due to loss of the biological activity.

The reaction of hexahydropyrroloindole (HPI) (46) with thiols to give the corresponding 2-thioether-tryptophan compounds has been further investigated (464). Reaction of cysteine with HPI (1.2 equiv) in 25% tri-fluoroacetic acid produces quantitatively tryptathionine, an amino acid contained in the toxic peptides of Amanita phalloides (see Section VI.2.4.). Reduced ribonuclease, a protein containing 8 cysteine residues per molecule, was treated with HPI, and the modified protein purified by gel filtration. The completeness of the reaction was confirmed by hydrolysis with /7-toluenesulfonic acid (233) and analysis of the hydrolyzate. A value of 7.6 (theory 8) residues per mole of protein of oxindolylalanine, the product of hydrolysis of the tryptathionine residues (431) (see Section III.4.2.), was obtained. This new reaction of cysteine residues should be of value in peptide synthesis, providing a simple method for linking tryptophan and cysteine as a basic step in the chemical synthesis of the peptides of Amanita phalloides. 

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