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The postharvest quality of winter jujubes is prone to deterioration, including inevitable pericarp reddening and rapid nutrient loss from the flesh, significantly impacting its edible quality and commercial value. As a crucial metabolic pathway in plants, phenylpropane metabolism not only regulates plant stress resistance but also closely relates to various coloration effects. In this study, we investigated the effects of luteolin solutions on postharvest color changes and phenylpropanoid metabolism in winter jujube. The results indicated that compared to the control group, winter jujube fruit treated with 200 mg L−1 luteolin exhibited improved quality indexes, increased antioxidant capacity (capability of eliminating ABTS and DPPH radicals), and higher activities of antioxidant enzymes(superoxide dismutase (SOD), and catalase (CAT)). This led to a reduction in the oxidation of phenolic substances in winter jujube. Furthermore, luteolin treatment inhibited phenylpropanoid metabolism by suppressing the activities of 4-Coumarate: coenzyme A ligase (4CL), phenylalanine ammonilyase (PAL), and cinnamate 4 hydroxylase (C4H), as well as the expression of ZjUFGT , ZjDFT , and ZjPAL genes. Consequently, anthocyanin and quercetin synthesis were limited while the degradation rate of chlorophyll and carotenoid synthesis were slowed down after luteolin treatment. This resulted in delayed reddening of winter jujube following luteolin treatment. In conclusion, luteolin exhibits potential application prospects as a preservative for inhibiting reddening and browning in winter jujubes. [Display omitted] • Luteolin treatment enhances the antioxidant activity of winter jujube. • Luteolin treatment delays the reddening of winter jujube. • Luteolin treatment reduces the activity of PAL, C4H, and 4CL. • Luteolin treatment inhibits the synthesis of anthocyanins and quercetin. • Luteolin treatment restricts the relative expression of ZjPAL , ZjDFR, and ZjUFGT. [ABSTRACT FROM AUTHOR]

A new method has been developed to prepare N -vinyl sulfoximines via a DABCO-participated Michael addition of carbonyl alkynes with N -chlorosulfoximines in the absence of metal. Various N -chlorosulfoximines and carbonyl alkynes were used as substrates in this novel protocol successfully, and only the corresponding (E)- N -vinyl sulfoximines were afforded in moderate yields. The establishment of this new synthetic method that featured good compatibility with air and high efficiency as well as the avoidance of transition metal would provide an alterative access to functional N -vinyl sulfoximines under green and simple conditions. A green and economical synthetic strategy for the preparation of N -vinyl sulfoximine via a DABCO-participated Michael addition of N -chlorosulfoximines and carbonyl alkynes has been developed here. A series of corresponding N -vinyl sulfoximines with E -configurations have been afforded in moderate yields. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Chcl-CA based UAE showed high efficiency in the green extraction of GSP. • Kinetic model is established to describe the extraction process of GSPs. • UAE-NADES enhanced the antifungal ability of GSPs. Ultrasonic-assisted extraction using a natural deep eutectic solvent (UAE-NADES) is an efficient method for extracting grape seed polyphenols (GSPs). In this study, response surface methodology was used to optimize the extraction of GSPs with UAE-NADES, and the theoretical extraction rate of GSPs was 139.014 mg GAE/g, the actual extraction rate was 135.78 ± 1.3 mg GAE/g. A pseudo-second-order kinetic extraction fitting was established to simulate the extraction process and mechanism (R2 > 0.99). Analysis of antioxidant capacity, Fourier-infrared spectroscopy and scanning electron microscopy revealed that UAE-NADES works synergetically to maintain the stability of extracted GSPs. The results of high-performance liquid chromatography showed that catechin (41.14 mg/g) is the main component of GSPs in the extract. The UAE-NADES extraction of GSPs can inhibit the growth of Alternaria alternata at 0.25 mg GAE/g, while the GSPs extracted by other methods can effectively inhibit the growth of Alternaria alternata at 0.35 mg GAE/g. Thus, this study demonstrates that UAE-NADES is a high-efficiency means of extracting GSPs and, in a wider sense, is a promising extraction technology for the green utilization of waste resources. [ABSTRACT FROM AUTHOR]