The existence of the 1,2-dicarbonyl compounds glyoxal,methyl glyoxal and diacetyl in autoxidised edible oils

The 1,2-dicarbonyl compounds glyoxal, methyl glyoxal and diacetyl which are known to be mutagens without metabolic activation in the Salmonella typhimurium TA100 system, were detected in autoxidised edible oils (sesame, safflower and sardine oil). The method is based on the fact that the 1,2-dicarbonyl compounds react with 4-chloro-1,2-phenylenediamine to give 6-chloroquinoxaline derivatives, which can be detected by ⁶³Ni ECD-gas chromatography. Glyoxal, methyl glyoxal and diacetyl were detected at 4.7, 7.0 and 1.6 μg g^?1, respectively, in 20 h autoxidised methyl linolenate. Glyoxal, methyl glyoxal and diacetyl were also detected at 6.5, 7.0 and 3.1 μg g^?1, respectively, in 30 h autoxidised sardine oil.     

Disulfide bond formation in refolding of thermophilic fungal protein disulfide isomerase

Disulfide bond formation in the refolding of thermophilic fungal protein disulfide isomerase (PDI) was investigated. It was revealed that (i) a disulfide bond buried inside the molecule is preferentially formed and contributes to the thermal stability and the isomerizing power of PDI, and (ii) formation of disulfide bonds in active sites located on the molecular surface causes deformation of the optimum conformation resulting in a decrease in the thermal stability.     

Electrochemical characteristics of an amorphous Mg0.9V0.1Ni alloy prepared by mechanical alloying

Electrochemical characteristics of an amorphous MgNi alloy with Mg partially substituted by V were investigated. A Mg_0.9V_0.1Ni alloy prepared by mechanical alloying (MA) exhibited much better cycle life than MgNi alloy. It was found that the partial substitution of Mg in MgNi with V could suppress the formation of Mg(OH)₂ on the alloy surface during the charge–discharge cycling in alkaline solution. This may have unveiled an important factor to improve cycle life of the Mg-based alloy for use in nickel–hydrogen batteries.