Functional sulfur compounds Communication 8. Synthesis of sulfur-containing aziridines and oxazolidines

1985 ◽  
Vol 34 (9) ◽  
pp. 1929-1933
Author(s):  
A. R. Derzhinskii ◽  
V. E. Kalugin ◽  
E. N. Prilezhaeva
Keyword(s):  
Sulfur Compounds ◽  
Sulfur Containing

scholarly journals New Gas-Phase Catalytic Oxidative Processes for Desulfurization of Diesel Fuel

2015 ◽  
Vol 17 (2) ◽  
pp. 119 ◽  
Author(s):  
Z.R. Ismagilov ◽  
M.A. Kerzhentsev ◽  
S.A. Yashnik ◽  
S.R. Khairulin ◽  
A.V. Salnikov ◽  
...  
Keyword(s):  
Gas Phase ◽  
Diesel Fuel ◽  
Ambient Pressure ◽  
Oxidative Desulfurization ◽  
Sulfur Compounds ◽  
Deep Desulfurization ◽  
Oxidative Processes ◽  
Laboratory Reactor ◽  
Sulfur Containing ◽  
Regeneration Processes

<p>An effective gas-phase oxidative desulfurization (ODS) process was proposed. The process was studied in a laboratory reactor with a proprietary catalyst at 300-400 ºС and ambient pressure with model fuels represented by thiophene, dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (DMDBT) dissolved in octane, isooctane or toluene. The reactivity of different sulfur containing molecules in ODS was shown to increase in the sequence: thiophene &lt; DBT &lt; DMDBT. The main sulfur containing product of oxidation of these compounds was SO<sub>2</sub>. During the gas-phase ODS both processes of sulfur species oxidation and processes of their adsorption were observed and studied. Based on the conducted studies, different ODS process designs comprising its integration with adsorption and regeneration processes and with conventional hydrodesulfurization (HDS) process were proposed. One scheme is based on alternating regimes of ODS and catalyst regeneration in two reactors: sulfur is removed from organic feedstock by oxidation and adsorption in one reactor while simultaneous regeneration of the catalyst that has accumulated sulfur  compounds takes place in another reactor. Two other schemes are based on joint use of ODS and HDS. The conventional HDS process is most effective for removal of low-boiling sulfur containing compounds reactive with respect to hydrogen, while removal of refractory sulfur compounds, such as DMDBT is more easily achieved by gas phase ODS. Thus the combination of these processes is expected to be most efficient for deep desulfurization of diesel fuel.</p>

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.

Equilibrium Analysis on Sulfur Material in Oxyfuel Combustion

2014 ◽  
Vol 986-987 ◽  
pp. 67-71
Author(s):  
Hai Ping Xiao ◽  
Gao Yan Han ◽  
Yu Kun Dai ◽  
Lin Dong
Keyword(s):  
Thermodynamic Equilibrium ◽  
Formation Rate ◽  
Equilibrium Concentration ◽  
Sulfur Compounds ◽  
Equilibrium Analysis ◽  
Conventional Combustion ◽  
Gas Formation ◽  
Oxyfuel Combustion ◽  
Excess Air Coefficient ◽  
Sulfur Containing

To study migration and transformation of sulfur species in oxyfuel combustion, the study attempts to analyze distribution of sulfur compounds with thermodynamic equilibrium. Results show that sulfur-containing gases predominantly are SO2 and SO3, the maximum thermodynamic equilibrium concentration of those in oxyfuel combustion respectively increase by 3.4 and 4.5 times compared with the conventional combustion. Furthermore, SO2 gas formation rate decreases while SO3 increases under oxyfuel combustion. Sulfur-containing gases are generally more sensitive to temperature and excess air coefficient. The amount of sulfur compounds significantly increases in oxyfuel combustion.

scholarly journals A METHOD TO MEASURE SULFUR-CONTAINING VOLATILES IN ONIONS USING A GAS CHROMATOGRAPH.

HortScience ◽  
1991 ◽  
Vol 26 (5) ◽  
pp. 492b-492
Author(s):  
Kil Sun Yoo ◽  
Leonard M. Pike
Keyword(s):  
Significant Variation ◽  
Peak Height ◽  
Sulfur Compounds ◽  
Soluble Solids ◽  
Gas Chromatograph ◽  
Horizontal Section ◽  
Dipropyl Disulfide ◽  
Sulfur Containing ◽  
Peak Pattern ◽  
Methyl Propyl Disulfide

A 50 g sample taken as a horizontal section from the mid-height of an onion bulb was blended with 100 g water for 1 min in a closed plastic mason jar. A 0.5 ml of a headspace sample was drawn and injected into a Perkin Elmer 8500 GC equipped with FPD for detection of sulfur compounds. The major volatiles tentatively identified in onion were thiopropanal S-oxide, methyl propyl disulfide, dipropyl disulfide, and propyl allyl disulfide. We observed significant variation of peak pattern and height depending on position in a bulb, among bulbs within variety, and between varieties. These results seemed to comply well with taste test. There were no significant correlations between total peak height and bulb weight, soluble solids, or pyruvate concentration in juice extract. Our investigation suggested that this procedure provided better understanding and measurement of onion pungency than pyruvate analysis.

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.

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