Sulfur-containing Substances Research Articles

Hydrogen sulfide preconditioning by garlic when it starts to smell

GARLIC (Allium sativum, Liliaceae/Alliaaceae) has long been used for medicinal and culinary purpose. Its first medicinal use was reported 400 years ago, and documented medicinal use can be found in a research finding of Louis Pasteur in the 1800s (8). Originally used as a digestive aid and as an antifungal, antibacterial, or antiviral compound (during the World Wars it achieved the nickname Russian penicillin), garlic was first reported to be a cardioprotective agent in the 1980s (13). Much of its cardioprotective abilities have been attributed toward its ability to function as an antioxidant (4). For example, garlic contains antioxidant vitamins A, C, and E as well as selenium, a key element for the synthesis of the antioxidant enzyme glutathione peroxidase (6). The study by Chuah, Moore, and Zhu (3) appears to be the first report where an alternative mechanism of cardioprotection is proposed. This report is based on the fact that garlic contains an organosulfur-containing compound, S-allylcysteine (12). Raw garlic contains alk(en)yl cysteine sulfoxides and -glutamyl alk(en)yl cysteines, which upon activation, is converted into S-allylcysteine (deoxyallin) because of the deactivation of the enzyme allinase. Allicin is then formed from S-allyl-L-cysteine according to following scheme:

Gas-chromatographic determination of volatile sulfur-containing impurities in industrial emissions and aqueous solutions

Procedures are developed for determining volatile sulfur-containing impurities, hydrogen sulfide, simple mercaptans, sulfides, and disulfides in air and aqueous solutions. The procedures are based on the principle’s headspace gas chromatography and equilibrium preconcentration. The procedures differ from the officially approved ones in that the operations of sampling and sample preparation to gas-chromatographic analysis considerably reduce the loss of hydrogen sulfide and mercaptans unstable in humid air. The procedures provide the determination of sulfur-containing substances at the level of their maximum permissible concentrations (MPC) in industrial emissions and natural waters and the analytical range of four orders of magnitude; they can be implemented on gas chromatographs with flame ionization and flame photometric detectors, a quartz capillary column, and a thermostated gas-sampling valve.

Atmospheric corrosion performance of carbon steel, galvanized steel, aluminum and copper in the North Brazilian coast

The main purpose of this study is to develop a method to characterize and classify the atmospheric corrosivity of the Sao Luis City, located at the Brazilian North coast, establishing 15 atmospheric corrosion sites (ACS), in different environments. These sites were monitored on a monthly basis to determine the deposition rates of atmospheric contaminants, such as airborne salinity, represented by chloride ions (Cl_), sulfur-containing substances, represented by SO2 and dustfall. These parameters were correlated to meteorological data and both were used to classify the atmospheric corrosivity. At the same time, metallic samples such as low carbon steel, galvanized steel, aluminum and copper, which are commonly used in transmission and distribution power lines, were exposed to the environment in four of these 15 sites, in order to qualify the environmental aggressiveness according to the corrosion rate of these materials. Based on the mapping results, it was possible to determine the materials which are more proper to be used in those specific areas, which could result in the cost reduction due to a span-life extension of such structures.

A method for evaluation of volatile sulfur-containing substances in preparations for intravenous infusions

Gas chromatographic method for measuring volatile sulfur compounds in solutions for intravenous infusions is proposed.

Keto sulfides derived from tert-dodecyl mercaptan and their extractive power with respect to palladium(II) and gold(III)

γ-Keto sulfide concentrates were prepared by alkylthiomethylation of propanone, butanone, and acetophenone with technical-grade tert-dodecyl mercaptan and other sulfur-containing substances, and their extractive power with respect to palladium(II) and gold(III) from hydrochloric acid solutions (chloroform as diluent) was studied.

The smell and odorous components of dried shiitake mushroom, Lentinula edodes III: substances that increase the odorous compound content

This study formed part of an effort to improve the quality of dried shiitake mushroom [Lentinula edodes (Berk.) Pegler], in accordance with consumer preferences, and deals with the search for substances that increase the odorous component content. From analysis of sulfur and sulfur-containing substances in the culture substrate, rice bran was found to be the main source of sulfur, and 75% of this was present as cysteine and methionine. The sulfur-containing substances were added to a sawdust medium containing only rice bran and sawdust as a substrate; shiitake mushrooms were cultivated in the medium, the fruiting bodies were dried, and the 1,2,4-trithiolane content in the fruiting bodies was measured as an indicator of the odorous compounds. Of the sulfur-containing substances, those that increased odorous compounds the most were cysteine and methionine. The efficiency of cysteine in this regard was higher than that of methionine. It was also noted that the amount of glutamic acid increased the odorous compounds in combination with cysteine and methionine. Furthermore, the addition of both amino acids and glutamic acid had no negative effect on the yield. These results showed that it is possible to produce dried shiitake mushrooms with a smell suitable for particular consumer preferences.

Microbiological Properties and Modes of Action of Organosulfur-based Anti-infectives

At least as long ago as the ancient Egyptians, sulfur-bearing natural products have been used for their potent medicinal properties. Although extracts from leeks were the earliest sulfur-containing substances to be employed for treatment of microbial and parasitic infections, a wide variety of natural and synthetically derived organosulfur compounds have been found to possess important antibiotic properties. There now exist, for virtually every class of human infection, representative examples of organosulfur anti-infective agents. By definition, these anti-infectives are compounds capable of preventing, inhibiting, or treating one or more types of infection. Except for their sometimes pungent odor and chemical instability, most antimicrobially active organosulfur compounds display few ill side effects. Given this era of drug resistance in which there is an ever-increasing demand for new antibiotics, organosulfur compounds may provide leads to novel therapies. In this review, we survey the microbiological properties and biochemical behavior of those organosulfur compounds whose activity depends specifically on the reaction of the organosulfur functionality with a biological target. The most common or likely mechanistic pathways by which these interactions occur are presented as a means to better understand the compounds modes of action, and to appreciate the opportunities that may exist towards designing yet even more effective anti-infective agents.

The Measurement of Sulfur-Containing Aroma Compounds in Samples from Production-Scale Brewery Operations

A method employing solid-phase microextraction followed by gas chromatography and detection by chemiluminescence has been used to measure sulfur-containing volatile substances in a range of beers and brewery process samples. Commercial beers were very similar in the types of sulfur-containing molecules contained. All beers tested, including ales, featured high levels of dimethyl sulfide, as well as methanethiol and S-methyl thioacetate. Only one beer was free from sulfur dioxide and only one was devoid of dimethyl disulfide. None of the beers contained detectable levels of ethanethiol, diethyl sulfide, or ethyl methyl sulfide. S-methyl thioacetate is most conspicuously a product of yeast metabolism, being produced from methanethiol. However, it is likely that the levels of dimethyl sulfide, sulfur dioxide, and perhaps methanethiol at the end of fermentation are a balance of substantial purging loss and replenishment by the action of yeast. There is an increase in the level of S-methyl thioacetate, at the expense of methanethiol, in ale that is naturally conditioned in the bottle. Prolonged postfermentation conditioning in tank also leads to an increase in the level of certain sulfur-containing volatiles, especially dimethyl sulfide and S-methyl thioacetate. Higher levels of sulfur volatiles were found in the same beer when packaged in kegs as opposed to bottles, presumably because of the extent to which volatiles are lost during purging operations.

Chemical characterization of interspecific hybrids between Allium cepa L. and Allium kermesinum Rchb.

Interspecific hybridization between wild and cultivated species of the genus Allium has been performed to generate plant material possessing biochemical properties of both parental plants. These cross-breeding experiments should lead to Allium plants with higher amounts of valuable constituents. The chemical characterization of interspecific hybrids between A. cepa and A. kermesinum is described on the basis of their sulfur-containing constituents and secondary metabolites. In addition, the hybrid character has been proven by random amplified polymorphic DNA (RAPD) analysis of the progenies obtained from the crosses. It has been shown that the distribution of the cysteine sulfoxides as well as the volatile secondary metabolites in the hybrids is not uniform. The profiles are mainly determined by the paternal wild species A. kermesinum. It has been ascertained that the gas chromatography profiles of the hybrids show increasing amounts of unsymmetrical substituted oligosulfides, which are known to be physiologically active substances. On the basis of statistical calculations, three different types of hybrids can be separated. The chemical analysis of cysteine sulfoxides and volatile sulfur-containing substances is shown to be a useful tool for breeding purposes as it allows an effective selection with regard to optimal distribution and amount of valuable constituents.

Inhibitory effects of isopropyl-2-(1,3-dithietane-2-ylidene)-2-[ N-(4-methylthiazol-2-yl)carbamoyl]acetate (YH439) on benzo[ a]pyrene-induced skin carcinogenesis and micronucleated reticulocyte formation in mice

Recently, a great deal of attention has been devoted to organosulfur compounds with potential cancer chemopreventive properties. Many sulfur-containing substances present in Brassica plants have been reported to possess striking anticarcinogenic and antimutagenic activities. Besides naturally occurring organosulfur compounds, certain synthetic sulfur-containing pharmaceuticals, such as oltipraz and sulindac, are known to exert substantial chemopreventive or chemoprotective effects. Isopropyl-2-(1,3-dithietane-2-ylidene)-2-[ N-(4-methylthiazol-2-yl)carbamoyl]acetate (YH439) was initially developed for its possible use as a hepatoprotectant. The compound has been found to up-regulate the expression of cytochrome P-450 IA1 [I.J. Lee, K.S. Jeong, B.J. Roberts, A.T. Kallarakal, P. Fernandez-Salguero, F.J. Gonzalez, B.J. Song, Transcriptional induction of the cytochrome P-450 1A1 gene by a thiazolium compound YH439, Mol. Pharmacol. 49 (1996) 980–988.] which plays a pivotal role in metabolism of the majority of polycyclic aromatic carcinogens and mutagens, such as benzo[ a]pyrene (B[ a]P). In the present study, we found that oral administration of YH439 to CD-1 mice significantly suppressed B[ a]P-initiated skin tumorigenesis. B[ a]P-induced formation of micronuclei in mouse peripheral reticulocytes was also attenuated by YH439 pretreatment. Likewise, diallyl sulfide, a major volatile thioether present in garlic, also protected against B[ a]P-induced skin tumorigenesis and micronucleated reticulocyte formation in mice.

Synthesis of Phthalic Anhydride: Catalysts, Kinetics, and Reaction Modeling

Information concerning the oxidation of o-xylene and naphthalene, the two main processes for producing phthalic anhydride, is updated and analyzed. New techniques for the preparation of catalysts, all based in the impregnation method and involving the control of parameters such as pH and ionic strength of solutions, are described; the performance of the resulting catalysts is compared with that of catalysts prepared by other methods. Sulfur-containing substances and promoters such as Ag, P, Nb, and Sb have been shown to enhance catalyst performance; studies of their effect on the surface area, acidic properties, and stabilization of the oxidation state of vanadium in supported V2O5 catalysts are described. The latest attempts to correlate the physicochemical characteristics of the catalysts with their catalytic features are analyzed. FTIR, Raman spectroscopy, adsorption of bases, 51V-NMR, XRD, XPS, SIMS, and electrical conductivity have been used in the study of V2O5/TiO2 catalysts, allowing further understanding of the effects of the properties such as acidity and the state of oxidation of the surface. Particular emphasis has been given to the presence of VIV, which is thought to cause lower selectivity to phthalic anhydride. For o-xylene oxidation, the formation of involatile by-products has been established as a secondary reaction, accounting for the poor carbon balances obtained under some experimental conditions. Involatile by-products, whose formation has been associated with the presence of strong acid sites, can adsorb on the catalyst surface, leading to deactivation, or undergo total combustion, acting as a source of CO2. Attempts to quantify and characterize those by-products are described. The modeling of the reaction using both fixed- and fluidized-bed reactors, including the study of parameters such as the inlet temperature and the bath temperature, is analyzed. Models considering catalyst deactivation have been also developed; for o-xylene oxidation, deactivation has been associated with processes both reversible, such as changes in the oxidation state of vanadium, deposition of involatile compounds, and irreversible, such as structural changes, decrease in surface area, sintering, and variation of the promoter concentration at the catalyst surface. The study of V2O5/TiO2 EUROCAT catalysts, involving a number of European laboratories, is reviewed, and their performance is compared with that of other V2O5/TiO2 catalysts.

A SPECTROSCOPIC STUDY OF THE SELF-REDOX REACTION OF SULFUR-CONTAINING COPPER(II) COMPLEXES

Studies on the self-redox reactions of copper(II) dithiophosphate, dithiophosphinate, dithiocarbonate, dithiocarboxylate and diselenophosphate complexes are summarized and, together with the results on the interaction of other sulfur-containing substances with copper (II), are discussed in order to evaluate their mechanism at a deeper level.

Chemopreventive effect of S-allylcysteine and its relationship to the detoxification enzyme glutathione S-transferase.

Sulfur-containing substances derived from garlic and onion have been shown to prevent experimental carcinogenesis. One of the hypotheses explaining the mechanisms of the chemopreventive activity of these substances is that they activate detoxification systems such as glutathione S-transferase (GST). In this study the effects of S-allylcysteine (SAC), a water-soluble organosulfur compound derived from garlic, on GST activities in the liver, small intestine and colon were investigated. Additionally, we examined SAC for chemopreventive effects on aberrant crypt foci, which are the most likely precursors of colon cancers. In the rat colonic aberrant crypt assay administration of SAC during the initiation period decreased the number of aberrant crypt foci by 33 and 54% in groups given 40 or 80% maximum tolerated dose (MTD) of SAC respectively. The number of aberrant crypt foci, however, was not changed when SAC was given during the promotion period. GST activity in the liver was increased significantly by 41% 12 h after a single oral administration of 3.5 mmol/kg SAC and this elevated GST level was maintained over a 72 h period. GST levels were increased significantly by the administration of SAC (1.8 mmol/kg/ day for 3 days) not only in the liver but also in the proximal and middle small bowel. Isozyme levels of GST after administration of SAC were also determined using Western blotting. Hepatic GST-alpha and GST-mu were significantly increased by 35 and 42% respectively after oral administration of SAC. GST-pi levels were lower than the detection limit (130 ng/mg/protein) in both the control and SAC-treated groups. These results strongly support the previous working hypothesis that SAC exhibits chemopreventive activity by exerting specific effects on carcinogen detoxification systems.

Effect of the pyrrolizidine alkaloid, monocrotaline, on bile composition of the isolated, perfused rat liver

Monocrotaline is a hepatotoxic pyrrolizidine alkaloid, releasing high levels of metabolites into bile of isolated, perfused liver. Although perfusion of rat liver with 0.5 mM monocrotaline does not affect bile flow over a 1 hr study period, it markedly affects bile composition. Biliary release of conjugated and free GSH increases 30-fold. Marked increases are also observed in the biliary concentration of the related sulfur-containing substances, cysteine and cysteinylglycine. However, biliary release of the sulfur amino acids, taurine and methionine, is unaffected. Only two amino acids show mildly increased releases, 23% for glycine and 46% for aspartate. Release of bile acids, cholesterol and phospholipids also decrease, both in terms of mM concentration in bile and in terms of nmol secreted per g liver. Thus, exposure to monocrotaline causes disturbances in sulfur metabolism in the liver and in the composition of bile. The consequences for the digestive properties of bile and gastrointestinal toxicity remain to be established. As sulfhydryl compounds are involved in detoxification of monocrotaline metabolites, these findings indicate a mutual interaction of pyrrolizidine toxicity and sulfur metabolism. This suggests that dietary sulfur amino acid intake may influence susceptibility to pyrrolizidine poisoning.

Inhibition of mushroom tyrosinase by sulfur-containing substances

Inhibition of mushroom tyrosinase by sulfur-containing substances

Biological Deodorization for Sulfur-Containing Offensive Odor and Sulfur-Oxidizing Bacteria.

Hydrogen sulfide, methanethiol, dimethyl sulfide and dimethyl disulfide are famous sulfur-containing offensive odor substances from sewage treatment facilities and night soil treatment facilities. In these facilities, deodorization methods are usually chemical absorption with NaOCl and adsorption with activated carbon, but the biological deodorization in sewage treatment facilities or night soil treatment facilities has been proved to be economical and efficient. In this mini review, the authors describe the study of the biological deodorization for sulfur-containing offensive odor and recently reported sulfur-oxidizing bacteria on hydrogen sulfide or methanethiol and so on, and their application to the biological deodorization for sulfur-containing offensive odor substances in sewage treatment facilities or night soil treatment facilities.

Metabolic pathways of sodium bisulfite injected intravenously in rabbits.

The metabolites of sodium bisulfite in rabbits through intravenous injection were examined according to the high performance liquid chromatography method for determination of sulfur-containing substances. Most of the administered sulfite was oxidized to sulfate, and a small part was converted to thiosulfate, S-sulfoalbumin, S-sulfoglutathione and S-sulfocysteine. Furthermore, it was found that S-sulfocysteine administered intravenously to a rabbit was partially changed to inorganic sulfate and thiosulfate. These metabolites produced from sulfite in rabbits indicated the presence of the many and complicated metabolic pathways of sulfite in vivo.

Effects of methionine and other sulfur compounds on drug conjugations

Conjugation reactions in the detoxification of drugs and environmental chemicals occur with various sulfur-containing substances. These reactions include: (1) glutathione (GSH, reduced glutathione) conjugation with subsequent mercapturic acid synthesis; (2) sulfate conjugation (sulfate ester synthesis); (3) methylation by S-adenosylmethionine (SAM); (4) thiosulfate conjugation of the cyanide ion, resulting in thiocyanate synthesis; (5) chelation of toxic metals by metallothionein, a sulfhydryl-rich protein. Of the drug conjugation reactions affected by methionine and cysteine intake and metabolism, sulfate and glutathione reactions have the greatest physiological significance. Much study has been devoted to the determination of intraand extracellular concentrations and transport of sulfur-containing compounds, and their relation to xenobiotic metabolism. Studies of the influence of dietary sulfur amino acid intake on the utilization during xenobiotic metabolism of sulfur-containing compounds are more limited, however. This review describes these studies as they relate to sulfur amino acid nutrition and Phase II drug conjugations. The major focus is on the effect of dietary methionine and cysteine intake on sulfate and glutathione conjugation reactions.

Simple Colorimetric Method for Determination of Episulfides, Using, 4-(p-Nitrobenzyl)-Pyridine

Abstract Episulfides were determined by a simple colorimetric assay using 4-(p-nitrobenzyl)-pyridine, which has been used previously for the detection and analysis of epoxides, organophosphates, and other alkylating agents. With episulfides, absorbance was directly proportional to concentration up to an absorbance of at least 1.0. No interference was observed with a variety of non-episulfide sulfur-containing substances. The colorimetric method is useful in monitoring 1-cyanoepithioalkane formation from the degradation of glucosinolates containing terminal double bonds.

The l-Methionine-Sparing Effect of Dietary Glutathione in Rats

The availability of cysteine moiety released from dietary glutathione (GSH) for protein synthesis in rats was studied to determine the l-methionine-sparing effect of this peptide. Animals were fed diets containing 18% of an amino acid mixture having a composition similar to that of whole egg, with or without GSH. The proportions of l-methionine, l-cysteine and GSH in the diet were varied, and one of these components was labeled with 35S. The incorporation of label into proteins and GSH in the liver and into proteins in the plasma was determined to assess the utilization of the sulfur atoms in these sulfur-containing substances. Dietary [35S]GSH was found to be incorporated efficiently into proteins and GSH in the liver and into plasma proteins. The results demonstrate the l-methionine-sparing effect of dietary GSH, in terms of incorporation of its 35S into proteins and GSH. GSH spared l-methionine almost as efficiently as l-cysteine in plasma protein synthesis, though slightly less in liver protein synthesis. The effect of GSH increased with increase in its concentration in the diet.methionine-sparing effect methionine cysteine glutathione liver protein plasma protein