Dinitrophenyl peptides. II. Further studies on the preparation and properties of 2,4-dinitrophenyl glycyl peptides

1967 ◽  
Vol 45 (13) ◽  
pp. 1505-1509 ◽  
Author(s):  
J. H. Loudfoot ◽  
Y. M. Chan
Keyword(s):  
Sodium Bicarbonate ◽  
Sodium Bicarbonate Solution ◽  
Good Separation ◽  
Acyl Chlorides ◽  
Aqueous Sodium ◽  
Infrared Absorption Spectra ◽  
Glutamic Acid Derivatives ◽  
Layer Chromatography ◽  
Aqueous Sodium Bicarbonate Solution

The study of 2,4-dinitrophenyl peptides has been extended to include the preparation and properties of some further dinitrophenyl dipeptides, namely, the glycyl-l-tryptophan, glycyl-l-proline, glycyl-l-phenylalanine, and glycyl-l-glutamic acid derivatives. Electrophoresis gave a good separation of products, and thin-layer chromatography proved to be a good means of purifying and separating the products. The molar absorbancy varies somewhat in the 350–360, 260–270, and 210–235 mμ, ranges in aqueous sodium bicarbonate solution, is more consistent in 95% ethanol at 344 mμ, and shows some variation in the 255–265 mμ region in 95% ethanol; the infrared absorption spectra have been obtained. The characterization of two dinitrophenyl amino acyl chlorides by conversion into the amides, anilides, and p-toluidides is also reported.

Comprehensive study of the toothpaste containing fluoride and 67% aqueous sodium bicarbonate solution

2021 ◽  
Vol 26 (2) ◽  
pp. 137-143
Author(s):  
S. N. Gromova ◽  
N. A. Guzhavina ◽  
E. A. Falaleeva ◽  
E. P. Kolevatykh ◽  
А. V. Elikov ◽  
...  
Keyword(s):  
Sodium Bicarbonate ◽  
Oral Care ◽  
Sodium Bicarbonate Solution ◽  
Comprehensive Treatment ◽  
Aqueous Sodium ◽  
Aqueous Sodium Bicarbonate ◽  
Periodontal Inflammation ◽  
Aqueous Sodium Bicarbonate Solution ◽  
Inflammatory Effect

Relevance. A wide variety of oral care products is available nowadays. Sometimes aggressive advertising rather than doctor’s advice determines our patients’ choice. In our research, we provide evidence of the clinical use of toothpaste containing fluoride and sodium bicarbonate.Materials and methods. During four weeks, we followed up a group of students who used the toothpaste containing 1400 ppm fluoride and 67% aqueous sodium bicarbonate solution. The clinical, biochemical and microbiological tests and saliva crystallization score assessed the characteristics stated by the manufacturer.Results. The statistically significant correlation between all studied criteria is evidence of the effectiveness of the toothpaste. In addition to the significant remineralization and antiplaque effect, biochemical and microbiological tests confirmed the anti-inflammatory effect of the toothpaste. An immediate cleaning effect was observed after the first brushing as well as in long-term use.Conclusion. Improvement of oral hygiene indices and reduction of periodontal inflammation confirmed the successful result of the comprehensive treatment of chronic gingivitis.

Analysis of Ochratoxins A and B and Their Esters in Barley, Using Partition and Thin Layer Chromatography. I. Development of the Method

1973 ◽  
Vol 56 (4) ◽  
pp. 817-821 ◽  
Author(s):  
Stanley Nesheim ◽  
Nicole F Hardin ◽  
Octave J Francis ◽  
William S Langham
Keyword(s):  
Sodium Bicarbonate ◽  
Diatomaceous Earth ◽  
Average Recovery ◽  
Aqueous Sodium ◽  
Lower Detection Limit ◽  
Aqueous Sodium Bicarbonate ◽  
Lower Detection ◽  
Tlc Plates ◽  
Layer Chromatography

Abstract A convenient, specific, rapid method, developed for the determination of ochratoxin in barley, involves initial extraction of the sample with water-chloroform (1+9), followed by chromatography of the extract on an aqueous sodium bicarbonate-diatomaceous earth column. The ochratoxin esters are removed from the column with hexane-chloroform. Elution of the column with formic acid-chloroform (1+99) yields ochratoxins A and B. The ochratoxin esters are purified further on an aqueous sodium bicarbonate-methanol-diatomaceous earth column. The extracts are then quantitated on TLC plates by measuring fluorescence intensity. The presence of ochratoxins A and B is confirmed through formation of the corresponding ethyl ester derivatives. In an intralaboratory study, in which samples spiked at 25, 50, and 100 μg/kg levels were analyzed by 4 analysts, the average recovery for ochratoxin A was 81.2% with a lower detection limit of 12 μg/kg.

Synthesis and Characterization of TiO2 Nanoreservoirs Supported with Platinum II and Sodium Bicarbonate Solution

2015 ◽  
Vol 5 (2) ◽  
Author(s):  
Jose Albino Moreno Rodríguez ◽  
Genaro Carmona Gutiérrez ◽  
Marco-Antonio González Coronel ◽  
Efraín Rubio Rosas ◽  
Lilián-Aurora Moreno Rodríguez ◽  
...  
Keyword(s):  
Sodium Bicarbonate ◽  
Sodium Bicarbonate Solution ◽  
Synthesis And Characterization

THE STRUCTURE OF SOME REACTION PRODUCTS OF THE ACIDIC URINARY METABOLITES OF PROGESTERONE

1968 ◽  
Vol 40 (2) ◽  
pp. 153-163 ◽  
Author(s):  
J. G. ALLEN ◽  
ALMA M. COOKE ◽  
G. H. THOMAS
Keyword(s):  
Sodium Bicarbonate ◽  
Thin Layer ◽  
Solution Treatment ◽  
Sodium Bicarbonate Solution ◽  
Urinary Metabolites ◽  
Reaction Products ◽  
Potassium Borohydride ◽  
Neutral Material ◽  
Layer Chromatography ◽  
Sodium Bismuthate

SUMMARY After injection of [4-14C]progesterone into rabbits, 62% of the radioactivity recovered from the urine after hydrolysis is extractable from ether into sodium bicarbonate solution. Treatment of these acidic metabolites with potassium borohydride, followed by sodium bismuthate, yields neutral material which can be separated into three zones by thin-layer chromatography. The most polar zone, accounting for 61% of the radioactivity recovered from the plate, consists of epimers of 3,6-dihydroxyandrostan17-al.

Determination of Cyclopiazonic Acid in Peanuts and Corn by Thin Layer Chromatography

1986 ◽  
Vol 69 (6) ◽  
pp. 964-966 ◽  
Author(s):  
John A Lansden
Keyword(s):  
Detection Limit ◽  
Sodium Bicarbonate ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Cyclopiazonic Acid ◽  
Chromatographic System ◽  
Aqueous Sodium ◽  
Absolute Detection Limit ◽  
Layer Chromatography

Abstract A thin layer chromatographic system including densitometry has been developed for determining cyclopiazonic acid in peanuts and corn. Samples are extracted with methanol-chloroform (20 + 80); the extract is stripped of most interferences by partitioning with aqueous sodium bicarbonate followed by acidification and repartitioning with chloroform. After thin layer chromatography and derivatization with dimethylaminobenzaldehyde- HCl spray, the toxin is quantitated by reflection densitometry at 540 nm. The recovery of cyclopiazonic acid averages 90% for peanuts and 85% for corn. The absolute detection limit is 25 ng per spot which translates to a detection limit of 125 μg/kg for a 50 g sample.

scholarly journals Gene Cloning and Molecular Characterization of a Two-Enzyme System Catalyzing the Oxidative Detoxification of β-Endosulfan

2002 ◽  
Vol 68 (12) ◽  
pp. 6237-6245 ◽  
Author(s):  
Tara D. Sutherland ◽  
Irene Horne ◽  
Robyn J. Russell ◽  
John G. Oakeshott
Keyword(s):  
Shuttle Vector ◽  
Open Reading Frame ◽  
Cosmid Library ◽  
Flavin Mononucleotide ◽  
Flavin Reductase ◽  
Reading Frame ◽  
Reductase Gene ◽  
Degradation Activity ◽  
Layer Chromatography

ABSTRACT The gram-positive bacterium Mycobacterium sp. strain ESD is able to use the cyclodiene insecticide endosulfan as a source of sulfur for growth. This activity is dependent on the absence of sulfite or sulfate in the growth medium. A cosmid library of strain ESD DNA was constructed in a Mycobacterium-Escherichia coli shuttle vector and screened for endosulfan-degrading activity in Mycobacterium smegmatis, a species that does not degrade endosulfan. Using this method, we identified a single cosmid that conferred sulfur-dependent endosulfan-degrading activity on the host strain. An open reading frame (esd) was identified within this cosmid that, when expressed behind a constitutive promoter in a mycobacterial expression vector, conferred sulfite- and sulfate-independent β-endosulfan degradation activity on the recombinant strain. The translation product of this gene (Esd) had up to 50% sequence identity with an unusual family of monooxygenase enzymes that use reduced flavins, provided by a separate flavin reductase enzyme, as cosubstrates. An additional partial open reading frame was located upstream of the Esd gene that had sequence homology to the same monooxygenase family. A flavin reductase gene, identified in the M. smegmatis genome, was cloned, expressed, and used to provide reduced flavin mononucleotide for Esd in enzyme assays. Thin-layer chromatography and gas chromatography analyses of the enzyme assay mixtures revealed the disappearance of β-endosulfan and the appearance of the endosulfan metabolites, endosulfan monoaldehyde and endosulfan hydroxyether. This suggests that Esd catalyzes the oxygenation of β-endosulfan to endosulfan monoaldehyde and endosulfan hydroxyether. Esd did not degrade either α-endosulfan or the metabolite of endosulfan, endosulfan sulfate.

Synthesis and chromatographic characterization of [Tc-99m]technetium-humic acid species

2000 ◽  
Vol 88 (2) ◽  
Author(s):  
D. Rößler ◽  
K. Franke ◽  
R. Süß ◽  
E. Becker ◽  
H. Kupsch
Keyword(s):  
Humic Acid ◽  
Stannous Chloride ◽  
Gel Permeation Chromatography ◽  
Paper Electrophoresis ◽  
Gel Permeation ◽  
Soil Humic Acid ◽  
Chromatographic Characterization ◽  
Ph Dependent ◽  
Layer Chromatography

A natural moor soil humic acid (HA) was labeled with Tc-99m via reduction of pertechnetate with stannous chloride. The humic acid species obtained were characterized by thin layer chromatography (TLC), gel permeation chromatography (GPC), sequential chromatographic analysis (SCA), paper electrophoresis and micropore filtration. Labeling was found to take place in all ranges of molecular weight. Due to the complex humic acid composition and the formation of hydroxo species the labeling yields strongly depend on the separation conditions, ranging from 42% to 80%. The pH-dependent distribution of mobile and immobile species was determined by SCA for HTcO

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