N,N-Diethyl-p-phenylenediamine effectiveness in analysis of polysulfides and polythionates in water

2008 ◽  
Vol 5 (3) ◽  
pp. 226 ◽  
Author(s):  
Stephen Kariuki ◽  
Philippe Babady-Bila ◽  
Breanna Duquette
Keyword(s):  
Oxidation State ◽  
Environmental Samples ◽  
Environmental Pollutants ◽  
Spectrophotometric Analysis ◽  
Sulfur Compounds ◽  
Metallic Ions ◽  
Sulfur Species ◽  
Related Compounds ◽  
Sulfur Containing ◽  
Sulfur Containing Compounds

Environmental context. The importance of hydrogen sulfide as well as some of the reduced sulfur species such as polysulfides as environmental pollutants is a result of their toxicity, unpleasant odour, and their reactivity with metals and metallic ions found in various environmental samples. Although known to be popular, the effectiveness of N,N-diethyl-p-phenylenediamine and other related compounds in the spectrophotometric analysis of such sulfur compounds in water as well as in other environmental samples has not been fully investigated. Our results show that although the quantification of simple sulfides in the environmental samples may be easily accomplished spectrophotometrically by using N,N-diethyl-p-phenylenediamine, the level of difficulty in analysing such compounds may increase with their increasing sulfur chain. Abstract. The analysis of polysulfides, polythionates and other sulfur species likely to be found in poorly aerated environmental samples such as water is presented. In-depth spectrophotometric testing carried out using N,N-diethyl-p-phenylenediamine shows that the well known acidification-and-purge method is not sufficiently suitable for the analysis of polysulfides and other low oxidation-state sulfur compounds that contain a sulfur chain longer than two. Further, this study finds that the use of chromium(II) which acts as a reducing agent to the sulfur-containing compounds improves the spectrophotometric analysis of the polysulfides and polythionates in water, but only slightly. The extent of reduction of polysulfides and polythionates to sulfide by chromium appears dependent upon the oxidation state of sulfur as well as the chain length in the polysulfidic compounds.

scholarly journals Sulfur and Sulfur Compounds in Plant Defence

2012 ◽  
Vol 7 (3) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Ifeanyi D. Nwachukwu ◽  
Alan J. Slusarenko ◽  
Martin C. H. Gruhlke
Keyword(s):  
Natural Products ◽  
New Technologies ◽  
Plant Defence ◽  
Sulfur Compounds ◽  
Oxidation States ◽  
Chemical Structures ◽  
Wide Range ◽  
Sulfur Containing ◽  
Sulfur Containing Compounds

The multiplicity of chemical structures of sulfur containing compounds, influenced in part by the element's several oxidation states, directly results in diverse modes of action for sulfur-containing natural products synthesized as secondary metabolites in plants. Sulfur-containing natural products constitute a formidable wall of defence against a wide range of pathogens and pests. Steady progress in the development of new technologies have advanced research in this area, helping to uncover the role of such important plant defence molecules like endogenously-released elemental sulphur, but also deepening current understanding of other better-studied compounds like the glucosinolates. As studies continue in this area, it is becoming increasingly evident that sulfur and sulfur compounds play far more important roles in plant defence than perhaps previously suspected.

Sulfatase regulation and antibiotic synthesis in Cephalosporium acremonium

1969 ◽  
Vol 15 (2) ◽  
pp. 175-181 ◽  
Author(s):  
David W. Dennen ◽  
Diane D. Carver
Keyword(s):  
Amino Acid ◽  
Culture Medium ◽  
Sulfur Compounds ◽  
Cephalosporin C ◽  
Cephalosporium Acremonium ◽  
Antibiotic Synthesis ◽  
Cellular Processes ◽  
High Level ◽  
Sulfur Containing ◽  
Sulfur Containing Compounds

The sulfatase of Cephalosporium acremonium is regulated by exogenous sulfur compounds, repressed in cells in 0.02 M sulfate, and derepressed in 5 × 10−4 M sulfate. Organic sulfur sources, such as cysteine, homocysteine, and methionine, derepress the enzyme in varying degrees while the latter amino acid is also required for maximum synthesis of the antibiotics cephalosporin C and penicillin N. Sulfatase-repressed cells transferred from sulfate to methionine-containing medium produce a high level of these antibiotics in the culture medium and a proportionate derepression of the sulfatase. Cycloheximide inhibits sulfatase derepression in cultures transferred from sulfate to methionine medium while having negligible effect on antibiotic synthesis. Mutant cultures of C. acremonium, with an increased potential to synthesize sulfur-containing antibiotics, have decreased ability to degrade methionine for other cellular requirements and sulfatase derepression is proportionately increased. The sulfatase is thus regulated by the biosynthesis of cephalosporin C and penicillin N at the expense of sulfur-containing compounds required for other cellular processes.

Incorporation of Antioxidant Groups into Polydienes. II. Via Free-Radical Reactions of Phenol- or Amine-Substituted Sulfur Compounds

1977 ◽  
Vol 50 (4) ◽  
pp. 650-659 ◽  
Author(s):  
A. H. Weinstein
Keyword(s):  
Free Radical ◽  
Chain Transfer ◽  
Spectrophotometric Analysis ◽  
Radical Reactions ◽  
Oxygen Absorption ◽  
Free Radical Reactions ◽  
Antioxidant Function ◽  
Absorption Studies ◽  
Sulfur Containing ◽  
Sulfur Containing Compounds

Abstract Methods for incorporation of effective antioxidant groups into both emulsion diene homo- or copolymers and stereospecific diene homopolymers via free radical reactions of sulfur-containing compounds were described. They involved either chain transfer reactions of phenol- or amine-substituted mercaptans or disulfides in emulsion diene polymerization systems or free-radical additions of phenol- or amine-substituted alkyl mercaptans to polydienes after polymerization. The latter reactions were applicable both to polydiene latexes and to solutions of stereospecific polydienes. The potential effectiveness of certain phenol- or amine-substituted mercaptans and disulfides to interact with polymer radicals was determined by measurement of chain transfer constants in bulk styrene polymerization. The efficiency of conferment of antioxidant activity upon polydienes by sulfur-containing compounds via chain transfer or addition reactions was determined by oxygen absorption studies of preextracted polymers. In some instances the relationship between the degree of oxidation resistance conferred upon a polymer with its concentration of chemically bound antioxidant function was determined by colorimetric or uv spectrophotometric analysis.

Review of the Syntheses and Activities of Some Sulfur-Containing Drugs

2020 ◽  
Vol 17 (3) ◽  
pp. 192-210 ◽  
Author(s):  
Criscieli Taynara Barce Ferro ◽  
Beatriz Fuzinato dos Santos ◽  
Caren Daniele Galeano da Silva ◽  
George Brand ◽  
Beatriz Amaral Lopes da Silva ◽  
...  
Keyword(s):  
Chemical Compounds ◽  
Sulfur Compounds ◽  
Important Class ◽  
Materials Chemistry ◽  
Drug Candidates ◽  
Wide Range ◽  
Synthetic Routes ◽  
Pharmaceutical Properties ◽  
Sulfur Containing ◽  
Sulfur Containing Compounds

Background: Sulfur-containing compounds represent an important class of chemical compounds due to their wide range of biological and pharmaceutical properties. Moreover, sulfur-containing compounds may be applied in other fields, such as biological, organic, and materials chemistry. Several studies on the activities of sulfur compounds have already proven their anti-inflammatory properties and use to treat diseases, such as Alzheimer’s, Parkinson’s, and HIV. Moreover, examples of sulfur-containing compounds include dapsone, quetiapine, penicillin, probucol, and nelfinavir, which are important drugs with known activities. Objective: This review will focus on the synthesis and application of some sulfur-containing compounds used to treat several diseases, as well as promising new drug candidates. Results: Due to the variety of compounds containing C-S bonds, we have reviewed the different synthetic routes used toward the synthesis of sulfur-containing drugs and other compounds.

Distribution of Sulfur Forms in Low Temperature Pyrolysis of Coal

2012 ◽  
Vol 512-515 ◽  
pp. 834-837
Author(s):  
Qiu Xiang Yao ◽  
Mei Li Du ◽  
Shui Li Wang ◽  
Jing Liu ◽  
Jian Li Yang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Coal Tar ◽  
Northwest China ◽  
Sulfur Compounds ◽  
Organic Sulfur ◽  
Total Sulfur ◽  
Low Temperature Pyrolysis ◽  
Sulfur Containing ◽  
Sulfur Containing Compounds ◽  
Typical Method

The distribution of sulfur forms in the products of low temperature pyrolysis of Carboniferous high sulfur coal from Northwest China was investigated. The typical method of Gray-King assay was used to carry out the low temperature pyrolysis experiments. GC-MS analysis was used to investigate the composition of sulfur compounds in the coal tar. The results show that sulfur mainly remained in the semi-coke and accounted for 80.97% of the total sulfur. Pyrites decomposed and transformed into sulfates and organic sulfur. 5 sulfur containing compounds were detected in the coal tar and they are dibenzothiophene, benzonaphthothiophene and their substituted homologs.

Molecular Reconstruction of Hydrocarbons and Sulfur-Containing Compounds in Atmospheric and Vacuum Gas Oils

2021 ◽  
Author(s):  
Aleksandar Bojkovic ◽  
Thomas Dijkmans ◽  
Hang Dao Thi ◽  
Marko Djokic ◽  
Kevin M. Van Geem
Keyword(s):  
Sulfur Containing ◽  
Sulfur Containing Compounds
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