Authors:David Cantillo, Phillip A. Inglesby, Alistair Boyd and C. Oliver Kappe
A safe and scalable procedure for the synthesis of 2-oxopropanethioamide, an intermediate in the synthesis of a potent β-secretase (BACE-1) inhibitor, from the reaction of acetyl cyanide with hydrogen sulfide gas under continuous-flow conditions has been developed. The toxic gas could be accurately dosed using a mass-flow controller or a peristaltic pump. The reaction proceeded smoothly at room temperature in the presence of a small amount of triethylamine as basic catalyst. After a residence time of 15 min, excellent yield (96%) and purity (>99%) were obtained for the target compound. The high reaction selectivity permitted a simple workup procedure consisting of evaporation of all volatiles.
Authors:S.-C. Ye, L.-Y. Hu, K.-D. Hu, Y.-H. Li, H. Yan, X.-Q. Zhang and H. Zhang
Hydrogen sulfide (H2S) has been recently found to be a gaseous signaling molecule in plants. In this work, we studied the role of H2S in alleviating salinity stress during wheat grain germination (Triticum aestivum L. Yangmai 158). Pretreatment with NaHS, a H2S donor, during wheat grain imbibition, could significantly attenuate the inhibitory effect of salinity stress on wheat germination. NaHS-pretreated grain showed higher amylase and esterase activities than water control. NaHS pretreatment differentially stimulated the activities of catalase (CAT), guaiacol peroxidase (POD) and ascorbate peroxidase (APX), decreased the level of malondialdehyde (MDA) and reduced NaCl-induced changes in plasma membrane integrity in the radicle tips of seedlings compared with water control. We conclude that H2S plays an important role in protecting wheat grain from oxidative damage induced by salinity stress.
Authors:M Stojanovic, V Zivkovic, I Srejovic, V Jakovljevic, N Jeremic and D Djuric
-lyase (CSE), and 3-mercaptopyruvate sulfur transferase] ( 19 ). These three enzymes break down Hcy into hydrogensulfide (H 2 S) ( 33 ). Together with nitric oxide ( • NO), carbon monoxide (CO), and methane, H 2 S belongs to a group of gaseous messengers
A method has been proposed for the determination of hydrogen sulphide and sulphur dioxide in a mixture. The method is based upon the quantitative oxidation of sulphide and sulphite with an excess of radiochloramine-T in alkaline medium /0.1N NaOH/. The released chloride activity is proportional to the total amount of sulphide and sulphite present. Addition of 1% CdSO4 solution to the mixture of sulphide and sulphite precipitates sulphide, and sulphite in the filtrate determined by the reagent. From the difference in activities, the amount of sulphide can be calculated. This method can be employed for the determination of hydrogen sulphide and sulphur dioxide in air samples.
Christou , A. , Manganaris , G.A. , Papadopoulos , I. , Fotopoulos , V.
2013 . Hydrogensulfide induces systemic tolerance to salinity and non-ionic osmotic stress in strawberry plants through modification of reactive species
Hydrogen sulphide at trace level can be determined by radiorelease technique using radiochloramine-T. The minimum detection level is 0.25 ppm. Zinc acetate is used to fix H2S from air samples. CS2 does not interfere. Interference by SO2 can be eliminated by oxidizing it with H2O2.
The Mössbauer analysis of rust samples obtained in the presence and absence of a magnetic field shows that there is a difference in the qualitative and quantitative composition of the corrosion products. The effect of magnetic field depends on the orientation of the coupons in the magnetic field and its intensity.