Search results for "Sodium bisulfite"
showing 3 items of 3 documents
Why do results conflict regarding the prognostic value of the methylation status in colon cancers? The role of the preservation method.
2012
Abstract Background In colorectal carcinoma, extensive gene promoter hypermethylation is called the CpG island methylator phenotype (CIMP). Explaining why studies on CIMP and survival yield conflicting results is essential. Most experiments to measure DNA methylation rely on the sodium bisulfite conversion of unmethylated cytosines into uracils. No study has evaluated the performance of bisulfite conversion and methylation levels from matched cryo-preserved and Formalin-Fixed Paraffin Embedded (FFPE) samples using pyrosequencing. Methods Couples of matched cryo-preserved and FFPE samples from 40 colon adenocarcinomas were analyzed. Rates of bisulfite conversion and levels of methylation of …
Changes of 1-Aminocyclopropane-1-Carboxylic Acid Oxidase Activity in Stressed Pinus Sylvestris Needles
2001
Stimulation of ethylene biosynthesis in pine needles by hydrogen peroxide and sodium bisulfite coincided with the activation of ACC oxidase at the level of protein synthesis. Decrease in ethylene production at high concentrations of sodium bisulfite (above 7 mM) was apparently due to inhibition of ACC oxidase activity. Treatment of pine needles with aminotriazole caused an inhibition of both ethylene production and ACC oxidase activity. Both methylviologen and methyl jasmonate stimulated ACC oxidase activity in a concentration-dependent manner with no parallel changes in ethylene production. The presented results suggest that ACC oxidase plays an important role in regulation of ethylene for…
Enantioselective addition of sodium bisulfite to nitroalkenes. A convenient approach to chiral sulfonic acids
2021
An enantioselective organocatalytic addition of sodium bisulfite to (E)-nitroalkenes has been developed by using a chiral bifunctional organocatalyst. The present methodology provides a variety of chiral β-nitroethanesulfonic acid compounds (17 examples) with excellent results: up to 99% yield and excellent enantioselectivity (up to 96% ee). The reaction tolerates (hetero)aryl and alkyl substituents on the β-nitroalkenes, and β,β-disubstituted nitroalkenes.