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Objectives: To develop a simple, rapid, and sensitive LC-MS/MS method for quantifying 23 tyrosine kinase inhibitors (TKIs) in plasma samples, and evaluate the relationship between the trough concentration of anlotinib(ANL) and its toxicities., Methods: The method was developed in Agilent 1290-6460 UHPLC-MS/MS system. This study prospectively enrolled 55 cancer patients undergoing ANL treatment. Plasma samples were collected at steady-state trough concentration and subsequently analyzed using the method. Patients were recorded for the occurrence of toxicities. Statistical analysis was performed to assess the association of the toxicities with ANL exposure level and patients' characteristics., Results: The LC-MS/MS method was developed and validated for all items required by pharmacopoeia. The results revealed a positive association between the trough concentration of ANL and the incidence of toxicities. The exposure level 17.655 ng/mL (AUC 0.82, p = 0.010) was identified as a predictive threshold value for grade ≥ 3 overall toxicities. In addition, lower platelet count (PLT count < 179 × 10 9 g/L) was significantly associated with higher occurrence of grade ≥ 3 toxicities (AUC 0.75, p = 0.049). A logistic model incorporating these two factors demonstrated improved diagnostic capacity for predicting ≥ 3 overall toxicities (AUC = 0.90, p = 0.001)., Conclusions: This study successfully developed and validated a simple, rapid, and sensitive LC-MS/MS method for quantifying 23 TKIs in plasma samples. Besides, this study found that both C trough of ANL and PLT count as independent predictors for ANL-induced ≥ 3 overall toxicities. Moreover, a logistic model including these two factors presents better prediction capacity for ≥ 3 overall toxicities., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Objective: To establish a rapid and universal quantitative liquid chromatography tandem mass spectrometry (LC-MS/MS) method for measuring the exposure levels of five triazole antifungal drugs in human plasma, including voriconazole, fluconazole, posaconazole, itraconazole, and hydroxyitraconazole., Methods: A triple quadrupole mass spectrometer operating in positive ionization mode was used to detect the analyte, and multiple reaction monitoring mode was employed to gather data. The mobile phase included 0.05 % formic acid in water (phase A) and acetonitrile (phase B). The analytes were separated on an Agilent EclipsePlusC 18 RRHD column (30 × 50 mm, 1.8 μm) using gradient elution. The flow rate was 0.3 mL/min with the column temperature set at 35 °C. The acetonitrile was used to pretreat the plasma sample, and the itraconazole-D5 and hydroxyitraconazole-D5 were utilized as the internal standards., Results: The calibration range was from 100 to 10,000 ng/mL for posaconazole, itraconazole, and hydroxyitraconazole, from 200 to 20,000 ng/mL for fluconazole and from 50 to 5000 ng/mL for voriconazole, with linear correlation coefficients more than 0.99 for all regression curves. The intra- and inter-day accuracy and precision of the method were within ±15 %. The mean extraction recovery of all the analytes ranged from 74.32 % to 117.83 %, and the matrix effect was from 72.54 % to 111.2 %. The results of stability fell into the scope of ±15 % deviation., Conclusion: This newly developed method is sensitive, simple, and robust, and successfully applied in determining triazole antifungal drugs in plasma from 66 IFI patients to provide reference for safe and effective drug administration in clinical practice., Competing Interests: Declaration of competing interest The authors declare no conflicts., (Copyright © 2024. Published by Elsevier Inc.)

Using the combination of affinity enrichment and high-resolution LC-MS/MS analysis, we performed a large-scale lysine malonylation analysis in the model representative of Gram-positive plant growth-promoting rhizobacteria (PGPR), Bacillus amyloliquefaciens FZB42. Altogether, 809 malonyllysine sites in 382 proteins were identified. The bioinformatic analysis revealed that lysine malonylation occurs on the proteins involved in a variety of biological functions including central carbon metabolism, fatty acid biosynthesis and metabolism, NAD(P) binding and translation machinery. A group of proteins known to be implicated in rhizobacterium-plant interaction were also malonylated; especially, the enzymes responsible for antibiotic production including polyketide synthases (PKSs) and nonribosomal peptide synthases (NRPSs) were highly malonylated. Furthermore, our analysis showed malonylation occurred on proteins structure with higher surface accessibility and appeared to be conserved in many bacteria but not in archaea. The results provide us valuable insights into the potential roles of lysine malonylation in governing bacterial metabolism and cellular processes., Biological Significance: Although in mammalian cells some important findings have been discovered that protein malonylation is related to basic metabolism and chronic disease, few studies have been performed on prokaryotic malonylome. In this study, we determined the malonylation profiles of Bacillus amyloliquefaciens FZB42, a model organism of Gram-positive plant growth-promoting rhizobacteria. FZB42 is known for the extensive investigations on its strong ability of producing antimicrobial polyketides and its potent activities of stimulating plant growth. Our analysis shows that malonylation is highly related to the polyketide synthases and the proteins involved bacterial interactions with plants. The results not only provide one of the first malonylomes for exploring the biochemical nature of bacterial proteins, but also shed light on the better understanding of bacterial antibiotic biosynthesis and plant-microbe interaction., (Copyright © 2016 Elsevier B.V. All rights reserved.)