TQ

Penicillium digitatum and Geotrichum citri-aurantii are fungi that cause green mold and sour rot, resp., both of which are postharvest diseases responsible for economic losses in oranges.Concerns about environmental and human health regarding agrochems. necessitate the investigation of effective disease control alternatives.This study aimed to investigate the in vitro effect of seven essential oils (EOs) on the mycelial growth of G. citri-aurantii and P. digitatum in orange, to identify the EOs with the highest antifungal activity, and to determine the minimal inhibitory concentration (MIC) of the selected EOs.Addnl., the chem. composition of two batches of EOs from the same plant species was analyzed using gas chromatog. with mass spectrometry (GC-MS), and the results were compared.The antifungal activity of the mixture of the major constituents of each selected EO was evaluated.According to the results, oregano, cinnamon bark, clove basil, and rosemary pepper EOs exhibited the most promising outcomes in inhibiting G. citri-aurantii and P. digitatum, with MIC of 0.25-3.0 μ L. mL-1.Despite being extracted from the same plant species, the two EO batches showed different profiles of chem. constituents and proportions.Concerning the antifungal activity of the constituents, the mixture of the three major EO constituents displayed greater antifungal activity than the pure EO, with MIC of 0.25-1.00 μ L. mL-1, suggesting an interaction among the mixture components.Therefore, using a mixture of the major constituents of EO represents a promising alternative to chem. fungicides commonly used for controlling postharvest diseases in oranges.

Thymoquinone (TQ), a compound with diverse pharmacological benefits, faces limited availability from natural sources. In this study, the design of a highly efficient electrocatalyst, Pt clusters loaded on CeO2 with rich oxygen vacancies (Vo‐Pt/CeO2), for the electrocatalytic oxidation of thymol (TY) or carvacrol to produce TQ is reported. The introduction of oxygen vacancies to the surface of Vo‐Pt/CeO2 significantly reduces the adsorption energy of TQ, facilitating its desorption and preventing product accumulation and catalyst poisoning. As a result, Vo‐Pt/CeO2 demonstrates exceptional electrocatalytic performance, achieving ≈100% selectivity and up to 98% yield of TQ under 1.2 VRHE. In situ, Raman spectroscopy indicates that the electrocatalytic oxidation mechanism of TY involves water attacking the TY intermediate to form thymohydroquinone, which is subsequently oxidized to TQ. Overall, this work provides novel insights into the catalyst design and presents a new strategy for sustainable TQ synthesis.