Postmortem metabolomics: influence of time since death on the level of endogenous compounds in human femoral blood. Necessary to be considered in metabolome study planning?

Introduction: The (un)targeted analysis of endogenous compounds has gained interest in the field of forensic postmortem investigations. The blood metabolome is influenced by many factors, and postmortem specimens are considered particularly challenging due to unpredictable decomposition processes.

Objectives: This study aimed to systematically investigate the influence of the time since death on endogenous compounds and its relevance in designing postmortem metabolome studies.

Identification of clobromazolam in Australian emergency department intoxications using data-independent high-resolution mass spectrometry and the HighResNPS.com database.

The proliferation of novel psychoactive substances (NPSs) continues to challenge toxicology laboratories. In particular, the United Nations Office on Drugs and Crime considers designer benzodiazepines to be a current primary threat among all NPSs. Herein, we report detection of a new emerging designer benzodiazepine, clobromazolam, using high-resolution mass spectrometry and untargeted data acquisition in combination with a "suspect screening" method built from the crowd-sourced HighResNPS.

Postmortem Metabolomics: Strategies to Assess Time-Dependent Postmortem Changes of Diazepam, Nordiazepam, Morphine, Codeine, Mirtazapine and Citalopram.

Postmortem redistribution (PMR) can result in artificial drug concentration changes following death and complicate forensic case interpretation. Currently, no accurate methods for PMR prediction exist. Hence, alternative strategies were developed investigating the time-dependent postmortem behavior of diazepam, nordiazepam, morphine, codeine, mirtazapine and citalopram.

LC-MSMS characterisations of scymnol and oxoscymnol biotransformations in incubation mixtures of rat liver microsomes.

The bile alcohol 5β-scymnol ([24R]-(+)-5β-cholestan-3α,7α,12α,24,26,27-hexol) is a therapeutic nutraceutical derived from marine sources, however very little is known about its potential for biotransformation as a xenobiotic in higher vertebrates. In this study, biotransformation products of scymnol catalysed by liver microsomes isolated from normal and streptozotocin (STZ)-treated male Wistar rats were characterised by liquid chromatography-tandem mass spectroscopy (LC-MSMS). In order of increasing polarity relative to the reversed phase sorbent, structural assignments were made for four biotransformation products, namely 3-oxoscymnol (5β-cholestan-3-one-7α,12α,24,26,27-pentol); 7-oxoscymnol (5β-cholestan-7-one-3α,12α,24,26,27-pentol); 3β-scymnol (5β-cholestan-3β,7α,12α,24,26,27-hexol) and 6β-hydroxyscymnol (5β-cholestan-3α,6β,7α,12α,24,26,27-heptol).

Hydroxysteroid dehydrogenase transformations of 5β-scymnol and identification of oxoscymnol transformation products by liquid chromatography-tandem mass spectroscopy.

A new and sensitive high performance liquid chromatography (HPLC) separation procedure coupled with tandem mass spectroscopy (MS and MS(2)) detection was developed to identify for the first time the oxidation products of 5β-scymnol [(24R)-(+)-5β-cholestan-3α,7α,12α,24,26,27-hexol] catalysed by bacterial hydroxysteroid dehydrogenase (HSD) reactions in vitro. The authentic scymnol (MW 468) standard yielded a protonated molecular ion [M+H](+) at m/z 469 Da, and higher mass adduct ions attributed to [M+NH(4)](+) (m/z 486), [M+H+CH(3)OH](+) (m/z 501) and [M+H+CH(3)COOH](+) (m/z 530). (24R)-(+)-5β-Cholestan-3-one-7α,12α,24,26,27-pentol (3-oxoscymnol, m/z 467 Da, relative retention time (RRT)=0.