Development of a targeted method for DNA adductome and its application as sensitive biomarkers of ambient air pollution exposure.

DNA adducts are widely recognized as biomarkers of exposure to environmental carcinogens and associated health effects in toxicological and epidemiological studies. This study presents a targeted and sensitive method for comprehensive DNA adductome analysis using ultra-high-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (UHPLC-QqQ-MS/MS). The method was developed using calf thymus DNA, with careful optimization of mass spectrometric parameters, chromatographic separation conditions, and pretreatment methods. Ultimately, a targeted method was established for 41 DNA adducts, which showed good linearity (R2 ≥0.992), recovery (80.1-119.4 %), accuracy (81.3-117.8 %), and precision (relative standard deviation <14.2 %). The established method was employed to analyze DNA adducts in peripheral blood cells from pregnant women in Shanxi and Beijing. Up to 23 DNA adducts were successfully detected in samples of varying sizes. From 2 µg of maternal DNA samples, seven specific adducts were identified: 5-methyl-2'-deoxycytidine (5-MedC), 5-hydroxymethyl-2'-deoxycytidine (5-HmdC), N6-methyl-2'-deoxyadenosine (N6-MedA), 8-hydroxy-2'-deoxyguanosine (8-OHdG), 5-hydroxy-2'-deoxycytidine (5-OHdC), 1,N6-etheno-2'-deoxyadenosine (1,N6-εdA), and N2-methyl-2'-deoxyguanosine (N2-MedG). This study reveals that exposure to higher concentrations of ambient air pollutants may elevate the levels of DNA methylation and oxidative damage at different base sites, highlighting the application potential of DNA adducts as sensitive biomarkers of air pollution exposure.

"Plant Golden" C. sativus: Qualitative and quantitative analysis of major components in stigmas and petals and their biological activity in vitro.

Crocus sativus L. (C. sativus) has its stigma as the main valuable part used. With extremely low production and high prices, stigma is considered a scarce resource. As a result, its petals, considered as by-products, are often discarded, leading to significant waste. We developed a UPLC-Q-Orbitrap HRMS method for qualitative analysis of stigmas and petals and a UHPLC-QQQ-MS/MS method for simultaneous quantification of 9 characteristic active compounds for the first time, and compared their biological activity in vitro. The results indicated that a total of 63 compounds were identified in the petals and stigmas. The content of flavonoids in the petals was significantly superior to that in the stigma, and the content of quercetin in the petals was 50 times higher than that in the stigma. The results of the in vitro evaluation of biological activity indicated that both the petals （•OH: IC50=39.70 mg/mL; DPPH: IC50=28.37 mg/mL; ABTS: IC50=0.9868 mg/mL）and stigma （•OH: IC50=34.41 mg/mL; DPPH: IC50=38.99 mg/mL; ABTS: IC50=3.194 mg/mL）demonstrated comparable antioxidant activities. However, the tyrosinase inhibitory activity in petals （IC50=21.17 mg/mL） was weaker than that in stigma（IC50=1.488 mg/mL）. This study provides a fast, reliable, and efficient analytical method that can be used for the quality assessment of petals as a natural resource and its related products in the food and pharmaceutical industries.

Cross-sectional, commercial testing, and chromatographic study of the occurrence of antibiotic residues throughout an artisanal raw milk cheese production chain.

This study investigated antibiotic utilization in artisanal dairies and residue occurrence throughout the raw milk cheese production chain using commercial testing (Charm KIS and Eclipse Farm3G) and UHPLC-QqQ-MS/MS and LC-QqQ-MS/MS. The cross-sectional survey results revealed gaps in the producers' knowledge of antibiotic use. Commercial testing detected antibiotic levels close to the LOD in 12.5 % of the samples, mainly in raw milk and whey, with 10.0 % testing positive, specifically in fresh and ripened cheeses, indicating that antibiotics are concentrated during cheese-making. Chromatographically, several antibiotics were identified in the faeces of healthy animals, with chlortetracycline (15.7 ± 34.5 µg/kg) and sulfamethazine (7.69 ± 16.5 µg/kg) predominating. However, only tylosin was identified in raw milk (3.28 ± 7.44 µg/kg) and whey (2.91 ± 6.55 µg/kg), and none were found in fresh or ripened cheeses. The discrepancy between commercial and analytical approaches is attributed to compounds or metabolites not covered chromatographically.

[Component profile analysis of Sanhan Huashi Formula based on UHPLC-LTQ-Orbitrap-MS, GC-MS, and UHPLC-QQQ-MS/MS].

This study comprehensively analyzed the active components of Sanhan Huashi Formula using qualitative and quantitative mass spectrometry techniques, laying the foundation for understanding its pharmacological substance basis. UHPLC-LTQ-Orbitrap-MS and GC-MS technologies were used to analyze and identify the volatile and non-volatile components in Sanhan Huashi Formula. UHPLC-QQQ-MS/MS technology was used to simultaneously determine the content of 27 major active components in the formula. The results showed that 308 major chemical components were identified in Sanhan Huashi Formula, among which 60 compounds were identified by comparing with reference standards, mainly including alkaloids, flavonoids, coumarins, triterpenoid saponins, amino acids, and nucleosides. GC-MS technology preliminarily identified 52 volatile compounds, with γ-eudesmol and ß-eudesmol as the main components. The quantitative results demonstrated good linearity(r>0.99) for the 27 active components, indicating the stability, simplicity, and reliability of the established method. Among them, amygdalin, nodakenin, arecoline, ephedrine, and pseudoephedrine had relatively high content and were presumably the main pharmacologically active substances. In conclusion, this study systematically and comprehensively characterized the major chemical components and patterns in Sanhan Huashi Formula, providing a basis for understanding its pharmacological mechanisms and clinical applications.