Haoying Zhang,Qi Zhang,Ting Zuo,Ziqi Wang,Jianmin Liao,Yuanyuan Lu
Candida albicans is an opportunistic pathogen, and the formation of its biofilm makes it resistant to traditional antifungal therapy. Anthraquinones have universal antibacterial activity. We evaluated the inhibitory effects of 2-chloromethyl anthraquinone on C. albicans adhesion, mycelial morphology transformation, and biofilm formation. The results showed that 2-chloromethyl anthraquinone could inhibit C. albicans adhesion, mycelium formation, and biofilm formation in a dose-dependent manner at 2 μg/mL. In addition, 2-chloromethyl anthraquinone significantly inhibited the expression of biofilm formation-related genes in C. albicans , including ALS1 , CPH1 , ECE1, HWP1 , TEC1 , BCR1 , and UME6 . In addition, Ras1-cAMP-Efg1 pathway-related genes ( RAC1 , CYR1 , and TPK2) were also significantly down-regulated, indicating that the inhibitory effect of 2-chloromethyl anthraquinone on C. albicans biofilms may be related to the Ras1-cAMP-Efg1 signaling pathway. In summary, the results of this study confirmed the inhibitory mechanism of 2-chloromethyl anthraquinone on the virulence factors of C. albicans , which laid a theoretical foundation for its use as an anti-biofilm agent against C. albicans .
Monitoring trace oxygenated polycyclic aromatic hydrocarbons (O-PAHs) in tea infusions is crucial, as long-term consumption of O-PAHs-contaminated tea can harm health. In this work, covalent organic framework (COF) TpBD-(OH) 2 coating was fabricated for solid-phase microextraction (SPME) of O-PAHs. The coating contains abundant benzene rings and hydrogen bonding sites (oxygen and nitrogen groups). Density functional theory calculations, electrostatic potential distribution and X-ray photoelectron spectroscopy analysis indicated the COF efficiently adsorbs O-PAHs via van der Waals force, hydrogen bonding, electrostatic force, size matching, and π-π interaction. Under the best SPME conditions, a method for detecting O-PAHs in tea infusions was developed using gas chromatography-tandem mass spectrometry (GC–MS/MS). The method possessed low limit of detection (0.5–1.0 ng L −1 ), wide linearity (2.0–1000.0 ng L −1 ) and satisfactory recoveries (82.5 %–117.5 %). Furthermore, the method was used to study the impacts of different roasting methods on O-PAHs contamination, and results showed carbon roasting posed a higher risk.
危险品化学品经营许可证（带存储）