Utilization of Folin−Ciocalteu Phenol Reagent for the Detection of Certain Nitrogen Compounds

Ikawa, Miyoshi; Schaper, Timothy D.; Dollard, Catherine; Sasner, John J.

doi:10.1021/jf021099r

Cited by 146 publications

(99 citation statements)

References 20 publications

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“…TMA concentration was measured in the medium by using the Folin-Ciocalteu phenol reagent as described in ref. 38. D. hafniense strain DCB-2 and D. dehalogenans strain JW/IU-DC1 were cultivated anaerobically in medium 717 recommended by the DSMZ with few modifications as described in ref.…”

Section: Methodsmentioning

confidence: 99%

Carbon source-dependent expansion of the genetic code in bacteria

Prat

Heinemann

Aerni

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

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Despite the fact that the genetic code is known to vary between organisms in rare cases, it is believed that in the lifetime of a single cell the code is stable. We found Acetohalobium arabaticum cells grown on pyruvate genetically encode 20 amino acids, but in the presence of trimethylamine (TMA), A. arabaticum dynamically expands its genetic code to 21 amino acids including pyrrolysine (Pyl). A. arabaticum is the only known organism that modulates the size of its genetic code in response to its environment and energy source. The gene cassette pylTSBCD , required to biosynthesize and genetically encode UAG codons as Pyl, is present in the genomes of 24 anaerobic archaea and bacteria. Unlike archaeal Pyl-decoding organisms that constitutively encode Pyl, we observed that A. arabaticum controls Pyl encoding by down-regulating transcription of the entire Pyl operon under growth conditions lacking TMA, to the point where no detectable Pyl-tRNA Pyl is made in vivo. Pyl-decoding archaea adapted to an expanded genetic code by minimizing TAG codon frequency to typically ∼5% of ORFs, whereas Pyl-decoding bacteria (∼20% of ORFs contain in-frame TAGs) regulate Pyl-tRNA Pyl formation and translation of UAG by transcriptional deactivation of genes in the Pyl operon. We further demonstrate that Pyl encoding occurs in a bacterium that naturally encodes the Pyl operon, and identified Pyl residues by mass spectrometry in A. arabaticum proteins including two methylamine methyltransferases.

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Section: Methodsmentioning

confidence: 99%

Carbon source-dependent expansion of the genetic code in bacteria

Prat

Heinemann

Aerni

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

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“…Probably, the exposure of an ultrasonic irradiation of 30 min caused negative effects like oxidation, degradation, and/or polymerization of the phenolic and flavonoid compounds [27,28,29]. As consequence, the derived secondary compounds could not be estimated by Folin-Ciocalteu reagent assay that, according to several authors, is not specific only for phenols [30,31,32]. Hence, based on the results and previous considerations, 20 min was selected as the extraction time for the subsequent UAE experiments.…”

Section: Optimization Of Uae Timementioning

confidence: 99%

Study of the Efficacy of Two Extraction Techniques from <i>Crithmum maritimum</i> and<i> Salicornia europaea</i>

Costa¹,

Padalino²,

Spinelli³

et al. 2018

JFNR

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The aim of this work was to study the characteristics of the extracts from two halophytes, sea fennel (Crithmum maritimum L.) and marsh samphire (Salicornia europaea L.) that naturally grow on the Mediterranean coast, by using ultrasound-assisted extraction (UAE) and supercritical fluid extraction (SFE). Best conditions for UAE were found at temperature 50°C, 20 min extraction time, 1:30 ratio solid:solvent and 40% (v/v) ethanol concentration. For SFE best conditions were at 50°C and 300 bar pressures with 40% (v/v) ethanol concentration. Total extract yield, total phenolic content, total flavonoid content and antioxidant capacity of the extracts were measured. For both species the best results were obtained with UAE technique. Between the two halophytes, the C. maritimum extract was the richest one in antioxidant compounds (total phenol = 23.44 mg GAE s g dw -1); under the best conditions the S. europea extract allowed recording only 9.31 mg GAE s g dw -1 of total phenol.

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“…O reagente consiste de mistura dos ácidos fosfomolibídico e fosfotunguístico, no qual o molibdênio e o tungstênio encontram-se no estado de oxidação 6 + porém, em presença de certos agentes redutores, como os compostos fenólicos, formam-se os chamados molibdênio azul e tungstênio azul, nos quais a média do estado de oxidação dos metais está entre 5 e 6 e cuja coloração permite a determinação da concentração das substâncias redutoras, que não necessariamente precisam ter natureza fenólica 4,11 .…”

Section: Determinação De Fenóis E Polifenóisunclassified