Studies on organo sulfur compounds. I. The reaction of prim. alpha-acetylenic alcohols and carbon disulfide.
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A new bacterial strain capable of selectively desulfurizing dibenzothiphene (DBT) was isolated from sludge. This organism, designated ZD-M2, clustered most closely with members of the genus Microbacterium, as determined by 16S rRNA gene sequence analysis. Metabolites produced by DBT desulfurization were identified by GC-MS, and two sulfur-free products, 2-methoxybiphenyl (2-MBP) and biphenyl, were detected in addition to 2-hydroxybiphenyl (2-HBP). This strain can also totally degrade 4,6-dimethyl-DBT, thiophene, benzothiophene and 70% diphenylsulfide.
In a study of the nutritional requirements of Propionibacterium acnes, acid hydrolyzed casein was shown to be the preferred nitrogen source in a glycerol-salts medium. Of 22 individual amino acids tested, only cysteine supported growth in the glycerol-salts medium. This indicated a requirement not only for amino nitrogen but also for reduced sulfur. In the presence of an auxiliary nitrogen source, thioglycolate or thiosulfate could replace sulfur-containing amino acids. The apparent requirement of P. acnes for reduced sulfur possibly could be satisfied in vivo by the constant availability of this substance in the form of sulfhydryl groups in the sebaceous follicle during keratinization. The relationship between P. acnes and its nutritional substrate may give this organism a selective advantage to exist in this ecological niche.
An investigation was conducted to test the feasibility of using gas chromatography with static headspace sampling as an objective tool to measure milk flavor quality. Heated milk off-flavor was chosen for study. Different strategies were tried for increasing the sensitivity of a commercially available headspace method, including salting out with sodium sulfate, cryofocusing during injection, and applying backpressure to the sampling loop. With the aid of a sulfur-specific detector, the resulting system was sufficiently sensitive to detect the sulfur volatiles, H2S and dimethyl sulfide, at the concentrations found in pasteurized skim milk. Milk that was heated to varying degrees was analyzed, and the analytical results were compared with the intensity of heated flavor as determined by a sensory panel. For skim milk, correlations were moderately strong: Spearman's correlation coefficients for H2S and dimethyl sulfide were .75 and .60, respectively. Correlations were weak for whole milk.
A sulfonic acid found to be a major constituent of spores of Bacillus subtilis was provisionally identified as 3-l-sulfolactic acid. This compound was completely absent from vegetative cells during growth, but large amounts accumulated in sporulating cells just before the development of refractile spores. Essentially all of the accumulated sulfolactic acid was eventually incorporated into the nature spore, where it may represent more than 5% of the dry weight of the spore. Germination resulted in the rapid and complete release into the medium of unaltered sulfolactic acid. This compound was not found in spores of Bacillus megaterium, B. cereus, or B. thuringiensis.
Sixteen isonitrogenous, isoenergetic diets were fed to fingerling channel catfish to study the efficacy of L-methionine, DL-methionine, methionine hydroxy analogue (OH-M), taurine and sodium sulfate. The basal diet contained casein and gelatin supplemented with crystalline L-amino acids to correspond to the amino acid pattern found in 24% crude protein from whole egg powder. The basal diet, containing 0.26% methionine was supplemented with graded levels of each of the sulfur sources on an isosulfurous basis. Growth and feed efficiency data indicate that channel catfish can utilize DL-methionine as effectively as L-methionine. OH-M was only about 26% as effective in promoting growth as L-methionine. No significant growth response was observed when taurine or inorganic sulfate was added to the basal diet.
Characterization of trace amounts of odorants in air in an ICU room (ca.257m2) was carried out by gas chromatography and atmospheric pressure ionization-mass spectrometry (API-MS). The concentrations and odor recognition threshold values of the detected odorants, acetaldehyde, ethanol, n-butyric acid, iso-valeric acid and n-valeric acid are as follows: 44.7 ppb and 15 ppb; 19710 ppb and 6100 ppb; 0.50 ppb and 0.4 ppb; 0.45 ppb and 0.4 ppb; 0.67 ppb and 0.5 ppb, respectively. The detected concentrations of these odorants were significantly higher than the odor recognition threshold values. The compounds may, therefore, be responsible for perception of such odors as mixed odors, body odor, and faint or recognizable alcoholic odor, disinfectant odor, and sour, pungent, and goat odors.
In 12 species of Fusobacterium the following characteristics were studied; the desulfhydration of L-cysteine and L-methionine by resting cell suspensions, the formation of alpha-keto-acids from L-cysteine, D-cysteine and L-methionine by cell extracts, and the formation of hydrogen sulfide from L-cysteine, D-cysteine and L-cysteine by cell extracts separated by polyacrylamide gel electrophoresis. Multiple forms of L-cysteine desulfhydrase activity were found in most of the species. In some of them also D-cysteine desulfhydrase activity was demonstrated. Seven of the species had high L-methionine gamma-lyase activity. L-cysteine activity was present in 5 of the species.
In order to invalidate or confirm the affirmation that non antithyroid sulphide molecules alter the measure of the thyroid fixation rate of iodine 131 we undertook on the rat: on one hand a kinetic study of thyroid fixation of sodium thiosulfate labelled with sulphur 35, which showed a very low captation not exceeding 0,01% of injected radioactivity; on the other hand the study of the effects of some sulphide molecules on thyroid fixation of iodine 131 in the rat: sodium thiosulfate, association of sodium thiosulfate + metalloidal sulphur + methionine, carbutamide and dimethylsulfoxyde in various kinds of dose administration and periods. None of the products used in our work conditions produced a significant decrease of the fixation rate of iodine 131. In three different experimental protocols (sulfur association and dimethylsulfoxide), we showed a significant light increase of the fixation rate.
The in vivo mitogenic responses to lipopolysaccharide or concanavalin A by spleen cells of mice exposed to 20 ppm nitrogen dioxide (NO2) for 96 hr, were evaluated. [3H]Thymidine incorporation after addition of either mitogen, was significantly lower in spleen cells from acutely NO2-exposed mice (NO2 SC) than from control mice, although cell viability was not affected. T- and B-cell mitogenic responses were inhibited to the same extent by NO2 exposure. NO2 SC responses were protected by the thiol compounds 2-mercaptoethanol, L-cysteine, and selenomethionine. No restoration of mitogenic response was observed after treatment with reduced glutathione. Mechanisms accounting for this in vivo NO2 immune toxicity, are discussed in terms of oxidative injury.
In this work, we present a complete study on He I photoelectron spectroscopy (PES) for the fluorocarbonyl mono-, di-, and trisulfur compounds FC(O)SCl, FC(O)SSCH(3), and FC(O)SSSC(O)F. After optimizations of the structure for stable conformers at different levels of theory, a complete theoretical study involving the calculation of the ionization energies using orbital valence Green's functional (OVGF) was performed. Calculations of radical-cationic forms were carried out in order to compare their properties with those of the neutral molecules. The first IP values are 10.7, 9.0, and 10.5 eV for FC(O)SCl, FC(O)SSCH(3), and FC(O)SSSC(O)F, respectively. The groups bonded to the S atom mainly influence the ionizations originating from the sulfur lone pairs. A wide electronic delocalization in the FC(O)S moiety can be deduced from experimental and theoretical results, which leads to a strong energetic stabilization of the n' '(S) (sulfur lone pair pi orbital). Other conclusions relate to effects on the substituents attached to the S atom and the importance of the molecular planarity in the orbital stabilization of the FC(O)S moiety for the neutral molecules. It is worthwhile mentioning that FC(O)SCl retains its planar structure after ionization, but drastic changes occur in the geometry of both FC(O)SSCH(3) and FC(O)SSSC(O)F. The FC(O)SSCH(3) molecule adopts a heavy atom planar structure after ionization. The FC(O)SSS moiety becomes a planar form after the ionization of the FC(O)SSSC(O)F molecule, whereas the second C(O)F group maintains its original conformation with respect to the SSS group.
The article justified hygienic principles for occupational screening in workers of Astrakhan gas-processing plant. The authors described algorithm to determine the jeopardy and hazard levels (ratings) for the individual workplaces, in accordance with the actual levels and concentrations of occupational hazards. The studies helped to assign the workers to several dispensary groups according to the occupational risk, length of service at every workplace and health state by the examination.