Thermochemistry of the reaction of hydrogen sulfide with iodine and the heat of formation of HSI - a new sulfur compound

1979 ◽  
Vol 101 (10) ◽  
pp. 2615-2617 ◽  
Author(s):  
R. J. Hwang ◽  
S. W. Benson
2015 ◽  
Vol 20 (2) ◽  
pp. 172
Author(s):  
Suryono Suryono

Volatile Sulfur Compound (VSC) merupakan komponen gas yang dihasilkan oleh bakteri dalam rongga mulut, terdiri dari Hidrogen sulfide, Methyl Mercaptan dan Dimethyl Sulfide. Ketiga komponen gas tersebut sering digunakan sebagai indikator untuk menilai status bau mulut seseorang. Pasta gigi berbasis herbal telah dilaporkan pada penelitian sebelumnya mampu menghambat pertumbuhan kuman penyebab penyakit periodontal. Bakteri plak dalam rongga mulut dapat dikurangi melalui cara gosok gigi dan/atau penggunaan material antiseptik. Dua kelompok subjek terpilih diberikan perlakuan dengan menggunakan pasta gigi herbal dengan cara yang berbeda, kelompok pertama dengan cara menggosok gigi dengan pasta gigi herbal sesuai dengan cara yang sudah biasa mereka lakukan dan kelompok ke-2 diberikan perlakuan dengan cara mengoleskan pasta herbal di daerah molar kiri dan kanan rahang atas. Pengambilan sampel nafas dilakukan sebelum perlakuan, 5 menit dan 2 jam paska menggosok gigi atau mengoles pasta herbal. Hasil pengamatan menunjukkan bahwa penggunaan pasta gigi herbal dengan cara sikat gigi maupun pengolesan memiliki pola yang sama pada masing-masing komponen gas sulfur yaitu peningkatan pada lima menit paska aplikasi kemudian menurun pada 2 jam paska aplikasi. Pasta gigi herbal yang diaplikasikan dengan cara gosok gigi maupun dengan cara pengolesan mempengaruhi kadar VSC yaitu yaitu menurunkan kadar Hydrogen sulfide, relatif stabil kadar methyl mercaptan dan terjadi peningkatan kadar dimethyl sulfide. Pasta gigi berbasis herbal dapat digunakan dengan cara sikat gigi maupun pengolesan untuk menurunkan kadar gas VSC, khususnya Hydrogen sulfide pada subjek normal.Effect of Herbal Toothpaste Application Method on Production of Volatile Sulfur Compound. Volatile sulfur compound (VSC) is a component of the gas produced by bacteria in the oral cavity, consisting of hydrogen sulfide,methyl mercaptan and dimethyl sulfide. This gas is often used as an indicator to assess the status of bad breath. Herbalbased dental paste has been reported in previous studies to inhibit the growth of germs that cause periodontal disease. Plaque Bacteria in the oral cavity can be reduced by tooth brushing and/or the use of antiseptic material. Two groups of subjects chosen were given treatment using herbal toothpaste in different ways: the first group was by brushing teeth with herbal toothpaste the way they usually do it and the second group was given the treatment by applying herbal paste in the left and right molar region of maxilla. The sampling was performed before treatment, 5 minutes and 2 hours after brushing teeth or applying herbal paste. The result of the experiment indicates that the use of herbal toothpaste with toothbrush and applying method has the same pattern on each component of the sulfur gas that is an increase after five minutes post-application and then a decrease after 2 hours post-application. Herbal toothpaste which is applied by means of brushing or by applying to the teeth affected the levels of VSC components; the level of Hydrogen sulfide decreased, the level of methyl mercaptan was relatively stable, and the level of dimethyl sulfide increased. Herbal toothpaste can be used in a common brushing way or by applying it to the teeth to reduce the levels of VSC gases, especially Hydrogen sulfide in normal subjects.


1930 ◽  
Vol 3 (3) ◽  
pp. 386-396
Author(s):  
Edward Wolesensky

Abstract The rubber-sulfur compound in vulcanized rubber splits off hydrogen sulfide at all times and at all temperatures between 25° C. and the temperature of complete thermal decomposition. The rate of evolution of the gas depends upon the temperature, time, the proportion of combined sulfur, and possibly other factors. The reaction affords a new explanation of the formation of hydrogen sulfide during vulcanization, and possibly also, in part at least, of the excess of combined sulfur over that required by the formula C5H8S. It may also be another factor in aging, though, perhaps, only a minor one, and presents a new problem in the regeneration of rubber.


2019 ◽  
Vol 133 (20) ◽  
pp. 2045-2059 ◽  
Author(s):  
Da Zhang ◽  
Xiuli Wang ◽  
Siyao Chen ◽  
Selena Chen ◽  
Wen Yu ◽  
...  

Abstract Background: Pulmonary artery endothelial cell (PAEC) inflammation is a critical event in the development of pulmonary arterial hypertension (PAH). However, the pathogenesis of PAEC inflammation remains unclear. Methods: Purified recombinant human inhibitor of κB kinase subunit β (IKKβ) protein, human PAECs and monocrotaline-induced pulmonary hypertensive rats were employed in the study. Site-directed mutagenesis, gene knockdown or overexpression were conducted to manipulate the expression or activity of a target protein. Results: We showed that hydrogen sulfide (H2S) inhibited IKKβ activation in the cell model of human PAEC inflammation induced by monocrotaline pyrrole-stimulation or knockdown of cystathionine γ-lyase (CSE), an H2S generating enzyme. Mechanistically, H2S was proved to inhibit IKKβ activity directly via sulfhydrating IKKβ at cysteinyl residue 179 (C179) in purified recombinant IKKβ protein in vitro, whereas thiol reductant dithiothreitol (DTT) reversed H2S-induced IKKβ inactivation. Furthermore, to demonstrate the significance of IKKβ sulfhydration by H2S in the development of PAEC inflammation, we mutated C179 to serine (C179S) in IKKβ. In purified IKKβ protein, C179S mutation of IKKβ abolished H2S-induced IKKβ sulfhydration and the subsequent IKKβ inactivation. In human PAECs, C179S mutation of IKKβ blocked H2S-inhibited IKKβ activation and PAEC inflammatory response. In pulmonary hypertensive rats, C179S mutation of IKKβ abolished the inhibitory effect of H2S on IKKβ activation and pulmonary vascular inflammation and remodeling. Conclusion: Collectively, our in vivo and in vitro findings demonstrated, for the first time, that endogenous H2S directly inactivated IKKβ via sulfhydrating IKKβ at Cys179 to inhibit nuclear factor-κB (NF-κB) pathway activation and thereby control PAEC inflammation in PAH.


Author(s):  
Roberto González-De Zayas ◽  
Liosban Lantigua Ponce de León ◽  
Liezel Guerra Rodríguez ◽  
Felipe Matos Pupo ◽  
Leslie Hernández-Fernández

The Cenote Jennifer is an important and unique aquatic sinkhole in Cayo Coco (Jardines del Rey Tourist Destination) that has brackish to saline water. Two samplings were made in 1998 and 2009, and 4 metabolism community experiments in 2009. Some limnological parameters were measured in both samplings (temperature, salinity, pH, dissolved oxygen major ions, hydrogen sulfide, nutrients and others). Community metabolism was measured through incubated oxygen concentration in clear and dark oxygen bottles. Results showed that the sinkhole limnology depends on rainfall and light incidence year, with some stratification episodes, due to halocline or oxycline presence, rather than thermocline. The sinkhole water was oligotrophic (total nitrogen of 41.5 ± 22.2 μmol l−1 and total phosphorus of 0.3 ± 0.2 μmol l−1) and with low productivity (gross primary productivity of 63.0 mg C m−2 d−1). Anoxia and hypoxia were present at the bottom with higher levels of hydrogen sulfide, lower pH and restricted influence of the adjacent sea (2 km away). To protect the Cenote Jennifer, tourist exploitation should be avoided and more resources to ecological and morphological studies should be allocated, and eventually use this aquatic system only for specialized diving. For conservation purposes, illegal garbage disposal in the surrounding forest should end.


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