Ethylene Formation from Methionine and its Analogs
Robert A. Greenwald in CRC Handbook of Methods for Oxygen Radical Research, 2018
The only commercial supplier of KMB that I have found is Sigma Chemical Co. It is listed in their catalog under α-keto-γ-methiolbutyric acid, sodium salt (catalog number K 6000). Methional is also available from Sigma under the name methional, or from Eastman Chemical or Alfa Chemical under the name 3-(methylthio)propionaldehyde. Methional is less expensive than KMB, but beware of its poor solubility in water and permeating odor. Precaution should be taken in storing methional. After breaking the seal on the methional bottle, it is recommended that the tightly capped bottle be placed in a separate container (e.g., a wide-mouth jar with screw cap) and stored in the freezer with sodium bisulfite in the outer container to minimize diffusion of the vile substance throughout the freezer and laboratory. Sodium bisulfite forms a nonvolatile addition product with aldehydes.
Trichothecenes
Dongyou Liu in Handbook of Foodborne Diseases, 2018
Sodium bisulfite (SB) greatly reduces DON content in the grain, and the extent of the reduction depends on the concentration of SB and the contact time. However, the treatment affects the rheological properties of the dough and hinders its suitability for commercial use.93 Some of these effects could potentially be attenuated by the combined use of SB and extrusion cooking.99 Extrusion cooking consists of the transformation of cereals into intermediate or finished products by a high-temperature short time passage through a food extruder and has been proposed to reduce mycotoxin levels in food. Reductions in >80% of the fumonisins, aflatoxins, and zearalenone contents in cereals have been reported, while lower reductions (<55%) were observed for DON.100 When a combination of SB and extrusion cooking was used in wheat grain and mill, Accerbi et al.99 found that extrusion of samples treated with SB did not reduce DON content significantly but attenuated the effects of SB on the rheological properties of the flour.
Corrosives
Bev-Lorraine True, Robert H. Dreisbach in Dreisbach’s HANDBOOK of POISONING, 2001
The following sulfur oxides occur as atmosphere contaminants: sulfur dioxide (SO2) and sulfur trioxide (SO3) along with the products of their reactions with water, sulfurous acid (H2SO3), and sulfuric acid (H2SO4), respectively. Sulfur monochloride (S2Cl2) and thionyl chloride (SOCl2) are used in industrial processes. A number of salts of sulfur oxides are used as bleaches, oxidizers, reducing agents, and cleaning agents. Their estimated fatal doses and exposure limits (if established) are as follows: sodium hydrogensulfate (sodium bisulfate, NaHSO4), 10 g; sodium sulfite (Na2SO3), 10 g; sodium hydrosulfite (sodium sulfoxylate, Na2S2O4), 30 g; sodium hydrogensulfite (sodium bisulfite, NaHSO3), 10 g, 5 mg/m3; sodium metabisulfite (Na2S2O5), 10 g, 5 mg/m3; sodium, potassium, or ammonium persulfate (Na2S2O8, K2S2O8, [NH4]2S2O8), 10 g, 0.5 mg/m3; sodium thiosulfate (Na2S2O3), 50 g. Sodium hydrosulfite releases sulfur dioxide on contact with acids. Persulfate salts release ozone and sulfuric acid on contact with water.
UV–Vis spectroscopic quantification of residual acetone during the development of nanoparticulate drug delivery systems
Published in Pharmaceutical Development and Technology, 2019
Sergio M. Espinoza, Rocio Guadalupe Casañas Pimentel, Eduardo San Martin Martinez
In general, samples for each experimental run consisted of an acetone aqueous solution prepared with NaHSO3, which was then introduced into a 10 mL calibrated flask along with NaOH and 2% m/v vanillin solution (prepared in 25% v/v ethanol in water). Afterward, leveling was performed with a 0.5% m/v NaHSO3 solution, which was prepared considering the percentage of Na2S2O5 in the granular sodium bisulfite. Sample and blank were transferred to a screw cap test tube, heated in a water bath, and then cooled before performing measurements. In the case of the first central composite design, heating time (10 and 30 min), heating temperature (40 and 80 °C) and cooling time (10 and 30 min) were contemplated as factors and were assessed by performing all experimental runs according to the experimental design (n = 3 for axial and factorial points, six central points). Sodium hydroxide solution concentration, vanillin solution volume, and acetone solution concentration were fixed at 1 M, 1 mL and ca. 5000 µg/mL, respectively. For experimental runs corresponding to the temperature axial point (92 °C, local water boiling point), a reflux apparatus was employed instead of the water bath.
Methylation of Specific CpG Sites in IL-1β and IL1R1 Genes is Affected by Hyperglycaemia in Type 2 Diabetic Patients
Published in Immunological Investigations, 2020
Naeimeh Roshanzamir, Vahideh Hassan-Zadeh
Four micrograms of DNA was treated with proteinase K (Sinaclon, Iran, MO5421) at 2 μg/μL final concentration and digested with EcoRI, BamHI or HindIII (Sinaclon, Iran) restriction enzymes to yield fragments less than 10 kb. Phenol-chloroform-extracted DNA was incubated with NaOH at 0.2 M final concentration for 30 min at 37°C for DNA denaturation. Each time, sodium bisulfite-hydroquinone solution was freshly prepared by dissolving 0.8 g sodium bisulfite (Thermo Fisher Scientific, Waltham, MA, USA, S654-500) in 1.6 mL water, adjusting the pH to 5.1 with 10 M NaOH and adding hydroquinone (Sigma-Aldrich, Saint-Louis, MO, USA, H9003) at 66 mM final concentration. A volume of 550 μL bisulfite-hydroquinone solution was added to the denatured DNA (50 μL) and incubated for 16 h at 50°C. A cleanup PCR kit (Genall Biotechnology, South Korea, 112–150) was then used to desalt and remove sodium bisulfite. Purified DNA was then treated with 0.3 M NaOH for 15 min at room temperature to complete bisulfite conversion. DNA was then precipitated by adding 100% ethanol, ammonium acetate and glycogen at 0.6 M and 36 ng/μL final concentration, respectively.
Liquid biopsy from research to clinical practice: focus on non-small cell lung cancer
Published in Expert Review of Molecular Diagnostics, 2021
Umberto Malapelle, Pasquale Pisapia, Alfredo Addeo, Oscar Arrieta, Beatriz Bellosillo, Andres F. Cardona, Massimo Cristofanilli, Diego De Miguel-Perez, Valeria Denninghoff, Ignacio Durán, Eloísa Jantus-Lewintre, Pier Vitale Nuzzo, Ken O’Byrne, Patrick Pauwels, Edward M. Pickering, Luis E. Raez, Alessandro Russo, Maria José Serrano, David R. Gandara, Giancarlo Troncone, Christian Rolfo
Genome-wide methylation is detected mainly by measuring the content of 5mC in the genome [85,95]. Almost all of the cfDNA methylation analysis methods depend on bisulfite sequencing, which transforms non-methylated cytosines to uracils after sodium bisulfite treatment while not altering methylated cytosines [85]. Following DNA sequencing, DNA methylation sites can be detected. Sodium bisulfite treatment would cause a degree of DNA degradation which may lead to loss of some critical information [96]. For example, WGBS-based methods produce the most comprehensive and high-resolution DNA methylome maps, but typically require sequencing to 30× coverage which is still expensive for routine analysis. Additionally, optimized approaches named single-cell reduced-representation bisulfite sequencing (scRRBS) and Methylated CpG tandems amplification and sequencing (MCTA-seq) aim at capturing CpG-enriched cfDNA fragments, which would lead to loss of some critical DNA methylation sites, reducing the sensitivity of the methods.
Related Knowledge Centers
- Chemical Decomposition
- Reducing Agent
- Sodium Bicarbonate
- Sodium Metabisulfite
- Sulfur Dioxide
- Chemical Formula
- Food Additive
- E Number
- Sodium Hydroxide
- Wellman–Lord Process