Trifluoromethylpyrimidine‑thiosemicarbazide derivatives as novel multifunctional food preservatives for enhancing storage stability of roxburgh rose juice

In this work, two predominant gas-generating spoilage fungi (labeled as CQ2 and CQ5) were isolated from deteriorated roxburgh rose ( Rosa roxburghii Tratt) juice and identified as Pichia nanzhaoensis and Arxiozyma slooffiae , respectively. Meanwhile, a series of novel trifluoromethylpyrimidine derivatives bearing a thiosemicarbazide group were synthesized. Biological activity evaluation demonstrated that compound 5a showed stronger antimicrobial efficacy against the isolated strains, with the EC 50 values of 10.63 μg/mL (CQ2) and 8.24 μg/mL (CQ5), respectively, than potassium sorbate (both exceeded 100 μg/mL); compound 5a also exhibited superior antioxidant activity, with the IC 50 values of 4.14 μg/mL (DPPH assay) and 2.95 μg/mL (ABTS assay), respectively, surpassing vitamin C (6.38 μg/mL) and trolox (8.04 μg/mL). Molecular docking and 100 ns dynamics simulations validated its stable binding to NADPH oxidase with the ΔE MMPBSA value of −36.458 kJ/mol, and ADMET analysis confirmed its desirable biosafety. In addition, application experiments confirmed that compound 5a effectively suppressed browning, conserved nutrients, and optimized the juice flavor of roxburgh rose juice during storage. Thus, these results suggest that compound 5a is a promising multifunctional preservative with integrated antimicrobial, antioxidant, and antibrowning activities for roxburgh rose juice and other fruit beverages.