Identification of in vitro and in vivo metabolites of 12β-hydroxylveratroylzygadenine associated with neurotoxicity by using HPLC–MS/MS

Metabolism study was carried out on 12b-hydroxylveratroylzygadenine（VOG） that is a cevine-type alkaloid existing in Veratrum nigrum L. and a neurotoxic component. In order to better understand the potential mechanism of neurotoxicity of VOG, this study measured VOG-induced DNA damage in the cerebellum and cerebral cortex of mice after 7 days repetitive oral dose by using single-cell gel electrophoresis（Comet assay）. High performance liquid chromatography-tandem mass spectrometry（LC–MS/MS） was developed and applied to separate and identify in vitro and in vivo metabolites of VOG for investing the possible relationship of metabolism and neurotoxicity. In vitro experiment was carried out using rat liver microsomes, while the in vivo study was conducted on rats. The obtained results indicated that VOG might cause DNA damage in cerebellum and cerebral cortex of mice in a dosedependent manner. Hydrolysis of ester bond and O-demethylation were proposed to be the main in vivo metabolic pathways of VOG, while the major in vitro metabolic pathways were proposed as methyl oxidation to aldehyde, dehydrogenation, hydrolysis of ester bond, hydrolysis of ester bond together with acetylation, and methoxylation. O-Demethylation reaction was likely to be associated with reactive oxygen species production, leading to the DNA damage.

Pollution characteristics of ambient PM_(2.5)-bound PAHs and NPAHs in a typical winter time period in Taiyuan

The pollution characteristics of ambient fine particulate matter（PM2.5） containing polycyclic aromatic hydrocarbons（PAHs） and nitrated PAHs（NPAHs） in samples collected during a typical winter time period in Taiyuan of China were investigated.The obtained results revealed that the mean mass concentrations of PM2.5,SPAHs（sum of 16 PAHs） and SNPAHs（sum of 3 NPAHs） on PM2.5were161.4 mg/m3,119.8 ng/m3and 0.446 ng/m3,respectively.Diagnostic ratios of PAHs and NPAHs implied that coal consumption might be the main source of the PM2.5pollution.The measured PM2.5mass concentrations,BaP equivalent toxicity（28.632 ng/m3） and individual carcinogenicity index（3.14 10 5） were much higher than those of the recommended safety standards.

Mass Spectrometry-based Proteomics and Glycoproteomics in COVID-19 Biomarkers Identification:A Mini-review

The first corona-pandemic,coronavirus disease 2019(COVID-19)caused a huge health crisis and incalculable damage worldwide.Knowledge of how to cure the disease is urgently needed.Emerging immune escaping mutants of the virus suggested that it may be potentially persistent in human society as a regular health threat as the flu virus.Therefore,it is imperative to identify appropriate biomarkers to indicate pathological and physiological states,and more importantly,clinic outcomes.Proteins are the performers of life functions,and their abundance and modification status can directly reflect the immune status.Protein glycosylation serves a great impact in modulating protein function.The use of both unmodified and glycosylated proteins as biomarkers has also been proved feasible in the studies of SARS,Zika virus,influenza,etc.In recent years,mass spectrometry-based glycoproteomics,as well as proteomics approaches,advanced significantly due to the evolution of mass spectrometry.We focus on the current development of the mass spectrometry-based strategy for COVID-19 biomarkers’investigation.Potential application of glycoproteomics approaches and challenges in biomarkers identification are also discussed.