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PubMed2001

Molar Refractivity and Connectivity Index Correlations for Henry's Law Virial Coefficients of Odorous Sulfur Compounds on Carbon and for Gas-Chromatographic Retention Indices.

Gas-solid chromatography was used to obtain values of the second gas-solid virial coefficient, B(2s), in the temperature range from 392 to 511 K for 10 volatile, malodorous organic sulfur compounds; ethanethiol, 1-propanethiol, methyl sulfide, 2-propanethiol, 1-methyl-1-propanethiol, 2-methyl-1-propanethiol, 2-methyl-2-propanethiol, ethyl sulfide, ethyl methyl sulfide, and tert-butyl methyl sulfide. Carbopack C (Supelco Inc.), a graphitized carbon black powder, was used as the adsorbent. Beginning with a theoretical equation for the second gas-solid virial coefficient, it was shown how a quantitative structure-retention relation (QSRR) could be developed to correlate ln B(2s) and hence chromatographic retention times with calculated molar refractivity and connectivity index values for the thiols and thioethers. It was found that both the gas-solid interaction energies and the ln B(2s) values could be correlated with calculated adsorbate molar refractivity (r(2)=0.951) and (r(2)=0.961), respectively. Connectivity index and molar refractivity together provide a r(2)=0.989 correlation of the ten ln B(2s) values at 403 K. A set of 373 organic compounds with retention indices taken from the literature was used to further test our approach. The 373 molecules were divided into 10 structural subgroups and molar refractivities and connectivity indices were calculated and used to correlate their retention index values. An overall correlation of r(2)=0.982 for the retention indices of the 373 molecules was found. Copyright 2001 Academic Press.

Journal Article↗
PubMed2001

Inhibition of methane oxidation by volatile sulfur compounds (CH3SH and CS2) in landfill cover soils.

Methanethiol and carbon disulphide were investigated for their ability to inhibit methane oxidation in two landfill cover soils. Methanethiol was found to be a competitive inhibitor, and at concentrations occurring in landfills, both these VSCs (volatile sulfur compounds) had inhibitory effects on the methane oxidation rates. Analysis of the phospholipid fatty acid contents in the soils indicated that type I-methanotrophs were more affected than type II. These effects of VSCs on methane oxidation are likely to have implications both for the establishment and the selectivity of a methane oxidizing microflora in landfills.

Air Pollution↗
PubMed1985

Protective action of sulfur compounds against aldehyde toxicants of cigarette smoke.

Acetaldehyde, acrolein, and formaldehyde are important toxicants of cigarette smoke. Since acetaldehyde is a toxicant common to both heavy alcohol drinking and heavy cigarette smoking, protection studies were undertaken in rats first against acetaldehyde lethality and later against acrolein and formaldehyde lethality. This paper summarizes findings from previously published studies. With acetaldehyde (LD 90 dose/72 hrs.) protection studies were carried out by pretreatment with a high oral dose (2 mmoles/kg) of L-cysteine and 17 other sulfur compounds. Good protection (80% or more survivors) was obtained with L-cysteine, N-acetylcysteine, thiamin . HCl, sodium metabisulfite, L-cysteic acid, and a combination (CTA) of L-cysteine, thiamin . HCl, and L-ascorbic acid. N-acetylcysteine, L-cysteic acid, and the combination CTA gave 100% protection (i.e. 100% survivors). With acrolein (LD 95 dose/72 hrs.), protection data showed 80% survivors with L-cysteine and 95% with the combination CTA. With formaldehyde (LD 95 dose/72 hrs.), protection resulted in 20% survivors with L-cysteine and 55% with the combination CTA. However, protection against formaldehyde lethality could be increased to 90% survivors by repeated dosing with L-ascorbic acid per se over a two day period prior to administration of formaldehyde. Further animal experimentation is necessary before any extrapolation of these findings for human use can be considered. Due to current interest, the potential value of N-acetylcysteine as a protectant is also discussed.

Acetaldehyde↗
PubMed2005

Environmental exposure to natural sour gas containing sulfur compounds results in elevated depression and hopelessness scores.

Some parts of Masjid-i-Sulaiman (MIS) (Khozestan provinces, southwest of Iran) are contaminated with subsurface leakage of natural sour gas containing H(2)S. It is reported that the incidence of suicide by self-burning in MIS is very high. High endogenous H2S levels have been found in the brain and it is involved in the brain functions. Because there is no report about the effect(s) of natural sour gas containing sulfur compounds on the function(s) of human brain, the present study was done. The study was performed on 128 individuals exposed or unexposed to natural sour gas. The exposed group consisted of 64 persons (39 males, 25 females). Unexposed subjects were matched by sex, age, and educational levels. Depression and hopelessness were determined using Beck's depression inventory (BDI) and Beck's hopelessness (BHS) questionnaires. Using multiple linear regression models, the averages of BDI (t=2.637, P=0.009) and BHS (t=3.344, P=0.001) were significantly higher among the exposed subjects than among the control group. In Lali 57.8% and 14.1% of subjects had no depressed mood and moderate to severe depressed mood, respectively, while in MIS 31.3% and 35.9% of subjects had no depressed mood and moderate to severe depressed mood, respectively; the difference was significant (chi2=12.88, df=3, P=0.005). In Lali 35.9% and 12.5% of subjects had no hopelessness at all and moderate to severe hopelessness, respectively, while in MIS 17.2% and 32.8% of subjects had no hopelessness at all and moderate to severe hopelessness, respectively, the difference was significant (chi2=11.49, df=3, P=0.009). Replication is necessary and health implications are discussed.

Adult↗
PubMed2003

"One-pot" two-step synthesis of aryl sulfur compounds by photoinduced reactions of thiourea anion with aryl halides.

[reaction: see text]. The photoinduced reactions of aryl halides with the thiourea anion afford arene thiolate ions in DMSO. These species without isolation, and by a subsequent aliphatic nucleophilic substitution, S(RN)1 reaction, oxidation, or protonation, yield aryl methyl sulfides, diaryl sulfides, diaryl disulfides, and aryl thiols with good yields (50-80%). This is a simple and convenient approach which involves the use of the commercially available and inexpensive thiourea in a "one-pot" two-step process for the synthesis of aromatic sulfur compounds.

Journal Article↗
PubMed1983

The excretion of sulfur compounds in the urine of newborn infants.

The excretion of sulfur-containing compounds was determined on the third and sixth day of life in male infants and the results were compared with those previously obtained on fed and fasting men. The output of total sulfur and inorganic sulfate was very low on the third day of life but had increased by the sixth day to levels found in the fasting men, whereas the excretion of mercaptolactate in the newborns decreased from the third to the sixth day of life. These results may be explained by the initial fasting state of neonates followed by an anabolic phase. Neonates excreted acid-labile ester sulfate and mercaptoacetate at levels similar to those found in adults, but the neonatal urine also contained sulfate esters (probably steroid sulfates) that required more drastic acid conditions for hydrolysis. Raised concentrations of sulfur-containing amino acids (methionine, cystathionine, cyst(e)ine and taurine) were found in neonatal urine in confirmation of earlier reports. The excretion of thiosulfate could only be determined in newborns on the sixth day and was low in comparison with that of adults. High urinary thiocyanate concentrations were found in newborns fed by tobacco-smoking mothers, whereas the excretion of thiocyanate was low in other newborns. The possible medical hazards from the exposure of neonates to thiocyanate are emphasized.

Adult↗
PubMed2005

Molecular detection and isolation from antarctica of methylotrophic bacteria able to grow with methylated sulfur compounds.

This study is the first demonstration that a diverse facultatively methylotrophic microbiota exists in some Antarctic locations. PCR amplification of genes diagnostic for methylotrophs was carried out with bacterial DNA isolated from 14 soil and sediment samples from ten locations on Signy Island, South Orkney Islands, Antarctica. Genes encoding the mxaF of methanol dehydrogenase, the fdxA for Afipia ferredoxin, the msmA of methanesulfonate monooxygenase, and the 16S rRNA gene of Methylobacterium were detected in all samples tested. The mxaF gene sequences corresponded to those of Hyphomicrobium, Methylobacterium, and Methylomonas. Over 30 pure cultures of methylotrophs were isolated on methanesulfonate, dimethylsulfone, or dimethylsulfide from ten Signy Island lakes. Some were identified from 16S rRNA gene sequences (and morphology) as Hyphomicrobium species, strains of Afipia felis, and a methylotrophic Flavobacterium strain. Antarctic environments thus contain diverse methylotrophic bacteria, growing on various C1-substrates, including C1-sulfur compounds.

Alphaproteobacteria↗
PubMed1978

Comparative immunological studies on arylsulfatase in bacteria of the family Enterobacteriaceae: occurrence of latent arylsulfatase protein regulated by sulfur compounds and tyramine.

The arylsulfatases of 21 strains of the family Enterobacteriaceae were compared by measuring their enzymatic activities and immunological reactivities. Enzyme formation under repressing, nonrepressing, and derepressing conditions was tested. Antiserum prepared against pure arylsulfatase from Klebsiella aerobgenes W70 was tested against the enzyme extracts from the strains using double diffusion, quantitative precipitation, and immunoelectrophoresis. No close relationship was found between arylsulfatase activity and immunological cross-reactionship was found between arylsulfatase activity and immunological cross-reactivity. The strains in the family Enterobacteriaceae could be divided into two groups on the basis of the immunological properties of their enzyme. Antisera formed a precipitin band with both active and inactive enzyme proteins from Escherichia, Citrobacter, Salmonella, Klebsiella, and Enterobacter, but not with the proteins from Serratia, Proteus, and Erwinia, even though some strains of these species had enzyme activity. It was also found that the formation of arylsulfatase proteins, irrespective of whether they had enzyme activity, were under regulation by sulfur compounds and tyramine.

Arylsulfatases↗
PubMed2006

Volatile organic sulfur compounds in anaerobic sludge and sediments: biodegradation and toxicity.

A variety of environmental samples was screened for anaerobic degradation of methanethiol, ethanethiol, propanethiol, dimethylsulfide, and dimethyldisulfide. All sludge and sediment samples degraded methanethiol, dimethylsulfide, and dimethyldisulfide anaerobically. In contrast, ethanethiol and propanethiol were not degraded by the samples investigated under any of the conditions tested. Methanethiol, dimethylsulfide, and dimethyldisulfide were mainly degraded by methanogenic archaea. In the presence of sulfate and the methanogenic inhibitor bromoethane sulfonate, degradation of these compounds coupled to sulfate reduction occurred as well, but at much lower rates. Besides their biodegradability, also the toxicity of methanethiol, ethanethiol, and propanethiol to methanogenesis with methanol, acetate, and H2/CO2 as the substrates was assessed. The 50% inhibition concentration of methanethiol on the methane production from these substrates ranged between 7 and 10 mM. The 50% inhibition concentration values of ethanethiol and propanethiol for the degradation of methanol and acetate were between 6 and 8 mM, whereas hydrogen consumers were less affected by ethanethiol and propanethiol, as indicated by their higher 50% inhibition concentration (14 mM). Sulfide inhibited methanethiol degradation already at relatively low concentrations: methanethiol degradation was almost completely inhibited at an initial sulfide concentration of 8 mM. These results define the operational limits of anaerobic technologies for the treatment of volatile organic sulfur compounds in sulfide-containing wastewater streams.

Anaerobiosis↗
PubMed2005

Catalytic ozonation of gaseous reduced sulfur compounds using wood fly ash.

The feasibility of reusing wood ash as an inexpensive catalyst in a catalytic ozonation process has been demonstrated. Catalytic ozonation was demonstrated to oxidize H2S, methanethiol (MT), dimethyl sulfide (DMS), and dimethyl disulfide (DMDS) at low temperatures (23-25 degrees C). The process oxidized 25-50% of an inlet MT stream at 70 ppmv without the formation of DMDS (contrary to ash plus oxygen in air), oxidized 90-95% of an 85 ppmv stream of DMS, and oxidized 50% of a 100 ppmv DMDS stream using 2 g of wood ash at a space velocity of 720 h(-1) using ozone concentrations ranging from 100 to 300 ppmv. Similarly, 60-70% conversion of a 70 ppmv H2S stream was achieved with 2 g of ash in 1.1 s without catalytic deactivation (approximately 44 h). The overall oxidation rate of H2S, DMS, and DMDS increased with increasing ozone concentration contrary to the oxidation rate of MT, which was independent of ozone concentration. Dimethyl sulfoxide and dimethyl sulfone were identified as the primary end products of DMS oxidation, and SO2 was the end product of H2S and MT oxidation.

Air Pollutants↗
PubMed2006

Protective effects of garlic sulfur compounds against DNA damage induced by direct- and indirect-acting genotoxic agents in HepG2 cells.

The aim of this study was to assess the antigenotoxic activity of several garlic organosulfur compounds (OSC) in the human hepatoma cell line HepG2, using comet assay. The OSC selected were allicin (DADSO), diallyl sulfide (DAS), diallyl disulfide (DADS), S-allyl cysteine (SAC) and allyl mercaptan (AM). To explore their potential mechanisms of action, two approaches were performed: (i) a pre-treatment protocol which allowed study of the possible modulation of drug metabolism enzymes by OSC before treatment of the cells with the genotoxic agent; (ii) a co-treatment protocol by which the ability of OSC to scavenge direct-acting compounds was assessed. Preliminary studies showed that, over the concentration range tested (5-100 microM), the studied OSC neither affected cell viability nor induced DNA damage by themselves. In the pre-treatment protocol, aflatoxin B1 genotoxicity was significantly reduced by all the OSC tested except AM. DADS was the most efficient OSC in reducing benzo(a)pyrene genotoxicity. SAC and AM significantly decreased DNA breaks in HepG2 cells treated with dimethylnitrosamine. Additionally, all the OSC studied were shown to decrease the genotoxicity of the direct-acting compounds, hydrogen peroxide and methyl methanesulfonate. This study demonstrated that garlic OSC displayed antigenotoxic activity in human metabolically competent cells.

Aflatoxin B1↗