Microdetermination of pentafluorobenzyl ester derivatives of organic acids by means of electron capture gas chromatography

Kawahara, Fred K.

doi:10.1021/ac60269a044

Cited by 103 publications

(21 citation statements)

References 9 publications

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“…Aromatic compounds were analyzed by injection of hexane extracts into a Hewlett Packard 5890 series II gas chromatograph equipped with an electron capture and flame ionization detectors, and a DB‐5 megabore capillary column. (Chloro)benzoic acids were similarly measured after formation of derivatives with pentafluorobenzyl bromide [19]. Chloride was measured via ion chromatography.…”

Section: Methodsmentioning

confidence: 99%

A novel bacterium that utilizes monochlorobiphenyls and 4-chlorobenzoate as growth substrates

Sang-Goo

Picardal

2000

FEMS Microbiology Letters

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A bacterial isolate, tentatively named SK-3, was isolated from tertiary lagoon sludge contaminated with polychlorinated biphenyls for over 25 years. SK-3 was able to grow on 2-chlorobiphenyl, 3-chlorobiphenyl, 4-chlorobiphenyl (4-CB), chloroacetate and 4-chlorobenzoic acid (4-CBA) as sole carbon and energy sources. During growth on 4-CB, a stoichiometric amount of chloride ion was produced and growth yields were comparable to those observed during growth on biphenyl. The production of 4-CBA as a metabolite was not observed. Protein yields during growth on 4-CB and biphenyl suggested that the presence of the chlorine did not impede use of carbons on both aromatic rings. Growth on 4-CBA also resulted in nearly stoichiometric production of chloride ion. Benzoate-grown SK-3 was also able to degrade several Aroclor 1242 congeners without the need for a primary substrate of previous growth on biphenyl.

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Section: Methodsmentioning

confidence: 99%

A novel bacterium that utilizes monochlorobiphenyls and 4-chlorobenzoate as growth substrates

Sang-Goo

Picardal

2000

FEMS Microbiology Letters

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“…Fatty Acid Analysis-Analysis for fatty acids was carried out on the various components of the system by negative ion, chemical ionization mass spectrometry after conversion to pentafluorobenzyl esters (35,36) following saponification of the fractions with 1 N KOH in 90% ethanol and extraction with ether:pentane 1:1 (37). Heptadecanoic acid was added as an internal standard, and octadeutereo-arachadonic acid or 1-stearoyl-2-arachidonyl phosphatidylcholine was added to some samples as an internal control.…”

Section: Methodsmentioning

confidence: 99%

The Farnesyl Group of H-Ras Facilitates the Activation of a Soluble Upstream Activator of Mitogen-activated Protein Kinase

McGeady

Kuroda

Shimizu

et al. 1995

Journal of Biological Chemistry

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To study the function of the farnesyl modification of Ras, the farnesyl group and a variety of its structural analogs, which lack one or more double bonds and/or the methyl groups, were enzymatically incorporated into recombinant H-Ras in vitro. These proteins were used in a cell-and membrane-free, Ras-dependent mitogen-activated protein kinase (MAP kinase) activation system derived from Xenopus laevis eggs to examine the contribution of the farnesyl group toward the activation of the kinase. Whereas non-farnesylated H-Ras is unable to activate MAP kinase, farnesylation of H-Ras alone, in the absence of further processing, is sufficient to cause the activation of MAP kinase in this system. All of the analogs of the farnesyl group, when incorporated into H-Ras, support the activation of the kinase to variable extents. These results suggest a direct but fairly nonspecific interaction of the farnesyl moiety of H-Ras with a soluble upstream activator of MAP kinase.The Ras GTP-binding proteins play a pivotal role in a variety of signal transduction and differentiation processes (1, 2). Ras is also involved in the generation of a number of human cancers, and several oncogenic point mutations of Ras are known (3, 4). Ras is activated by the conversion of the GDP-bound inactive form to the GTP-bound active form in response to various extracellular signals (5). A variety of extracellular signals can activate mitogen-activated protein kinase (MAP kinase) 1 (also known as extracellular signal-regulated kinase (ERK)) through both Ras-dependent and Ras-independent mechanisms (6). A Ras-dependent pathway linking the epidermal growth factor receptor to MAP kinase, through the protein kinase Raf, has been elucidated (7,8). A Ras-dependent, Raf-independent MAP kinase activation system has also been identified (9, 10).Ras proteins are part of the group of proteins that are post-translationally prenylated (11). In the case of Ras, this modification involves the attachment of the farnesyl group to the protein through a thioether linkage to a cysteine located four residues from the carboxyl terminus, followed by removal of the three carboxyl-terminal amino acids and methylation of the newly exposed ␣-carboxyl group of the farnesyl cysteine residue (12). Additionally, H-Ras and N-Ras, but not K-Ras, undergo palmitoylation at one or more upstream cysteine residues (13). Although necessary for the normal and oncogenic functions of many proteins, including Ras (14), the specific properties imparted by these post-translational modifications have, to a large extent, remained unclear. Prenylation of proteins has been implicated in membrane binding (13, 15) and in protein-protein recognition (16, 17). Furthermore, the relative contribution of each of the processing steps is unknown.Previously we developed a cell-free assay system, derived from Xenopus laevis eggs, to identify a direct target molecule for Ras. In this system, Ras promotes the activation of MAP kinase through MAP kinase kinase/ERK kinase (MEK). Using this system, we have iden...

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“…The following procedure by Chien et al, (1998) and Galceran et al, (1995) In another example of pentafluorobenzylation procedure (Naritisin andMarkey, 1996 &Kawahara, 1968), 20 μl of PFBBr is added to the vial containing already extracted and cleaned sample in methyl chloride. The vial is then capped and shaken for 20 -30 minutes.…”

Section: Organic Acids Derivatisationmentioning

confidence: 99%

Derivatization Reactions and Reagents for Gas Chromatography Analysis

Orata¹

2012

Advanced Gas Chromatography - Progress in Agricultural, Biomedical and Industrial Applications

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Microdetermination of pentafluorobenzyl ester derivatives of organic acids by means of electron capture gas chromatography

Cited by 103 publications

References 9 publications

A novel bacterium that utilizes monochlorobiphenyls and 4-chlorobenzoate as growth substrates

A novel bacterium that utilizes monochlorobiphenyls and 4-chlorobenzoate as growth substrates

The Farnesyl Group of H-Ras Facilitates the Activation of a Soluble Upstream Activator of Mitogen-activated Protein Kinase

Derivatization Reactions and Reagents for Gas Chromatography Analysis

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