7-Deoxyloganin 7-hydroxylase in Lonicera japonica cell cultures

The activity of 7-deoxyloganin 7-hydroxylase, an enzyme catalyzing the conversion of 7-deoxyloganin into loganin, was detected in a microsomal preparation from the cell suspension cultures of Lonicera japonica. It was dependent on NADPH and molecular oxygen. The enzymatic reaction was inhibited by carbon monoxide as well as by several cytochrome P450 inhibitors, especially ketoconazole, indicating that the reaction was mediated by cytochrome P450. The enzyme showed substrate specificity for 7-deoxyloganin. The K(m) values for 7-deoxyloganin and NADPH were estimated as 170 and 18 microM, respectively, from Lineweaver-Burk plots.

Identification of reaction products of methamphetamine and hydrogen peroxide in hair dye and decolorant treatments by high-performance liquid chromatography/mass spectrometry

The effect of hydrogen peroxide, a main component of hair dye and decolorant treatments, on methamphetamine (MA) was studied. Two analytical methods, thin-layer chromatography (TLC) and high-performance liquid chromatography/mass spectrometry (LC/MS), were used for the separation and identification of MA derivatives. Mixtures of MA solutions and hydrogen peroxide that had been incubated at 39 degrees C for 24 h were shown to contain para-hydroxy MA by TLC and para-, meta- and ortho-hydroxy MAs by LC/MS. In addition, MA N-oxide and N-hydroxy MA were found in MA/hydrogen peroxide mixtures immediately after mixing. Therefore, we concluded that MA changed to MA N-oxide and N-hydroxy MA before changing to para-, meta- and ortho-hydroxy MAs.