Degradation of the ethyl glucuronide content in hair by hydrogen peroxide and a non-destructive assay for oxidative hair treatment using infra-red spectroscopy.

The assessment of quantification results of the alcohol abuse marker ethyl glucuronide (EtG) in hair in comparison to the cut-off values for the drinking behavior may be complicated by cosmetic hair bleaching. Thus, the impact of increasing exposure to hydrogen peroxide on the EtG content of hair was investigated. Simultaneously, the change of absorbance in the range of 1000-1100 cm(-1) indicative for the oxidation of cystine was investigated non-destructively by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) using pulverized portions of the respective hair samples. Hair samples treated with hydrogen peroxide consistently displayed a significantly increased absorbance at 1040 cm(-1) associated with the formation of cysteic acid. The EtG content decreased significantly if the hair was treated with alkaline hydrogen peroxide as during cosmetic bleaching. It could be shown that ATR-FTIR is capable of detecting an exposure to hydrogen peroxide when still no brightening was visible and already before the EtG content deteriorated significantly. Thus, hair samples suspected of having been exposed to oxidative treatment may be checked non-destructively by a readily available technique. This assay is also possible retrospectively after EtG extraction and using archived samples.

Detection and quantification of new designer drugs in human blood: Part 2 - Designer cathinones.

In recent years, derivatives of cathinone, a naturally occurring beta-keto phenylethylamine, have entered the illicit drug market. These compounds have been marketed over the internet or in so-called head shops as "legal highs" and have gained popularity among drug users. Numerous fatalities due to the abuse of these drugs in recent years have increased the need for their detection in human blood samples. For detection and determination of 25 designer cathinones and their related ephedrines in blood samples, a liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was developed using only 100 µL of blood. The blood was extracted using liquid-liquid extraction with 1 mL of 1-chlorobutane containing 10% of isopropanol. The final extract was analyzed using a Shimadzu 8030 LC-MS-MS system operated in electrospray positive ionization multiple reaction monitoring mode. The method has been validated according to international guidelines and was found to be selective for all tested compounds. Calibration for all 25 studied analytes was satisfactory from 10-1,000 ng/mL. Accuracy data were within the acceptance interval of ±15% [±20% at the lower limit of quantification (LLOQ)] of the nominal values for all drugs. Within-day (repeatability) and intermediate precision data were within the required limits of 15% relative standard deviation (RSD) (20% RSD at LLOQ).

N-(Pyridin-3-yl)benzamides as selective inhibitors of human aldosterone synthase (CYP11B2).

A series of 23 N-(Pyridin-3-yl)benzamides was synthesized and evaluated for their potential to inhibit human steroid-11ß-hydroxylase (CYP11B1) and human aldosterone synthase (CYP11B2). The most potent and selective CYP11B2 inhibitors (IC(50) values 53-166 nM) were further evaluated for their potential to inhibit human CYP17 and CYP19, and no inhibition was observed. Clear evidence was shown for N-(Pyridin-3-yl)benzamides to be a highly selective class of CYP11B2 inhibitors in vitro.