This review focuses on green oxidation methods for benzylic and allylic C-H bonds. Traditional synthesis methods often require pre-introducing functional groups like halogens or hydroxyl groups to activate substrates. Such approaches are not only cumbersome but also pose environmental risks. In contrast, modern methods take advantage of the σ-π hyperconjugation effect, which facilitates the activation of benzylic and allylic C-H bonds. This allows for direct functionalization without pre-functionalization, aligning with the principles of green chemistry. Photocatalysis activates C-H bonds via hydrogen atom transfer (HAT) by exciting metal complexes through ligand-metal charge transfer (LMCT) and generates products in combination with green oxidants such as oxygen. Photoelectric cooperative catalysis integrates electrochemical and photochemical steps to break through the redox window limitations of single catalytic systems and achieve highly selective C-H functionalization. In terms of green oxidants, methanol as an oxygen source in electrochemical oxidation is compatible with various benzylic substrates containing functional groups, while water enables metal-free and oxidant-free carbonylation through radical-polar crossover mechanisms in photocatalysis. Challenges include nanosecond-scale radical lifetimes and low catalytic efficiency, mitigated by substrate-catalyst pre-coordination. Future directions involve dual-ligand design and "metal-photocatalyst-electrochemistry" ternary systems to enhance selectivity and atom economy for sustainable synthesis.

In this study, we investigated the effects of collagen peptides (CP) and elastic peptides (EP) on UV-induced photoaging in HaCaT, B16, and ESF cells. We measured hyaluronic acid (HA), melanin, and collagen levels, as well as the expression of related genes and proteins, to evaluate their potential and combined effects. Compared with UV-irradiated controls, HA content increased by 87.57 % (CP), 39.13 % (EP), and 97.60 % (combined treatment). Both peptides enhanced collagen levels, reduced melanin content, and exhibited synergistic effects. Additionally, CP and EP significantly increased Superoxide Dismutase (SOD) and Glutathione Peroxidase (GSH-Px) activities in HaCaT cells, decreased Malondialdehyde (MDA) levels, upregulated Has2 mRNA, and downregulated Hayl1 mRNA. In B16 cells, they downregulated key melanogenesis-related genes and proteins (MITF, CREB, PKA, TYR, TRP-2). In ESF cells, they upregulated genes involved in collagen metabolism (Tgf-beta, Smad3, P4ha2, Adamts2, Bmp1, Lox). The combination index method confirmed their synergistic effects on improving skin photoaging. Our findings suggest that CP and EP can ameliorate skin photoaging by modulating key biomolecules in hydration, melanogenesis, and collagen metabolism, providing a basis for developing antiphotoaging strategies.

Conversion of biogas into syngas expands its application scope from fuel for power generation to industrial feedstock for the synthesis of value-added chemicals; however, it is restricted to the limited CH4 conversion due to the mismatch between CH4/CO2 feeding ratios of biogas and the stoichiometry of the CH4 dry reforming reaction. Herein, we proposed a novel calcium-looping biogas dry reforming process (CaL-BR) to supplement exogenous CO2 into biogas in situ by the introduction of a CaO-based carbon-carrying cycle. Using the facilely prepared composite material CaO-Ni/Al2O3_1 for CaL-BR at 750 degrees C, the CH4 conversion was over 65% and 16.4% higher than that of conventional biogas reforming, enabling the syngas yield to reach as high as 136.7 mmol/g. Importantly, the proposed process exhibited superior cyclic stability with a decay in the biogas reforming performance below 3% over 20 CaL-BR cycles under typical biogas CH4/CO2 feeding ratios, which was confirmed to be a consequence of the suppressed sintering of Ni particles and carbon deposition. The proposed CaL-BR process offered a promising option to make the best of the CH4 resource in biogas with the simultaneous capture and conversion of CO2.

The bacterial microbial community composition during wine fermentation is a key contributor to wine quality and flavor. However, studies on the regulatory effects of different grape varieties and co-fermentation processes on the microbial community structure and their synergistic mechanisms remain limited. In this study, Cabernet Sauvignon (CS) was subjected to single-variety fermentation and used as the base wine for co-fermentation with three other grape varieties—Marselan (CSMN), Merlot (CSMT), and Cabernet Gernischt (CSCG)—to systematically compare the differences in the microbial community composition and their effects on the production of metabolic compounds. The results showed that, compared with single-variety fermentation, co-fermentation significantly increased the α-diversity of microbial communities (the Shannon index increased) and exhibited significant differences in β-diversity (PERMANOVA analysis, R2 = 0.421, p < 0.001). A neutral model analysis indicated that co-fermentation had a significant impact on microbial community assembly mechanisms, with the contribution of neutral processes to community assembly increasing from 45.5% (in the CSCG process) to 62.3% (in the CSMT process). A microbial co-occurrence network analysis revealed that co-fermentation enhanced the network complexity of microbial communities and strengthened the synergistic interactions between microbial taxa. A metabolic compound analysis revealed that co-fermentation significantly enhanced the production of key aroma compounds, resulting in increased concentrations of isoamyl acetate, ethyl hexanoate, linalool, and geraniol. These findings highlight the differences in microbial communities and their synergistic mechanisms among co-fermented grape varieties, providing theoretical guidance and practical insights for optimizing co-fermentation processes and improving wine quality.

Chemical looping reforming of methane (CLRM) with Fe-based oxygen carriers is widely acknowledged as an environmentally friendly and cost-effective approach for syngas production, however, sintering-caused deactivate of oxygen carriers at elevated temperatures of above 900 °C is a longstanding issue restricting the development of CLRM. Here, in order to reduce the reaction temperature without compromising the chemical-looping CH4 conversion efficiency, we proposed a novel operation scheme of CLRM by manipulating the reaction pressure to shift the equilibrium of CH4 partial oxidation towards the forward direction based on the Le Chatelier's principle. The results from thermodynamic simulations showed that, at a fixed reaction temperature, the reduction in pressure led to the increase in CH4 conversion, H2 and CO selectivity, as well as carbon deposition rate of all investigated oxygen carriers. The pressure-negative CLRM with Fe3O4, Fe2O3 and MgFe2O4 could reduce the reaction temperature to below 700 °C on the premise of a satisfactory CLRM performance. In a comprehensive consideration of the CLRM performance, energy consumption, and CH4 requirement, NiFe2O4 was the Fe-based OCs best available for pressure-negative CLRM, especially for an excellent syngas yield of 23.08 mmol/gOC. This study offered a new strategy to address sintering-caused deactivation of materials in chemical looping from the reaction thermodynamics point of view.

皮肤光老化是紫外线通过损伤皮肤真皮层和表皮层而诱导的皮肤衰老,主要体现在 3 个方面:皱纹与松弛、屏障功能受损及干燥粗糙、色斑与晒斑.由于生活压力和环境污染程度日益增加,现代人群的皮肤衰老速度逐渐加快,如何改善皮肤衰老已经成为了人们的关注热点.胶原蛋白肽(collagen peptide,CP)与弹性蛋白肽(elastin peptide,EP)是由胶原蛋白和弹性蛋白制得的低分子活性肽,能够从上述三方面展现出优良的抗光老化活性.该文对CP和EP制备工艺进行探讨,同时从CP和EP如何减少皱纹、保湿、美白的角度出发,对两种肽抗皮肤光老化的机理进行综述,以期为CP和EP的日常食用及蛋白肽产品的开发提供科学参考.

Wheat bran (WB) is largely discarded during processing, resulting in wastage of the bioactive components in it, such as ferulic acid (FA) and pentosans. The aim of this study was to enhance their yield by solid-state fermentation with three filamentous fungi (Aspergillus oryzae, Rhizopus oryzae, and Aspergillus niger). Through single-factor experiments, the optimal fermentation conditions were found to be a strain of A. oryzae, an inoculation amount of A. oryzae of 4 x 10(5) spores/g, a moisture content of 60%, a fermentation temperature of 28 degrees C, and a fermentation time of 48 h. By 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), and 2,2'- azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods, the antioxidant activities of fermented WB were found to be significantly improved. Also, there was a good correlation between the total phenolics content (TPC) and antioxidant capacity. Briefly, fermentation not only provides a new avenue to increase the functional potential of WB, but also enhances the utilization of agricultural byproducts.

Aims Oxidative stress limited the growth of cells and 2-keto-l-gulonic acid (2-KGA) production in vitamin C (Vc) fermentation system. The study aims to investigate the antioxidant effect of glutathione on promoting 2-KGA in Vc fermentation system using Ketogulonicigenium vulgare 25B-1 and Bacillus endophyticusST-1 as the co-culturing microbes. Methods and ResultsConclusionsThe activities of antioxidant-related enzymes and qPCR were used to study the antioxidant effect of glutathione addition in Vc fermentation system. The addition of GSH and GSH/GSSG increased 2-KGA production and decreased fermentation time, and the highest 2-KGA production increased by 4063% and the lowest fermentation time shortened to 60h when the addition of optimal concentration ratio of GSH/GSSG was 50:1. Moreover, the increased production of 2-KGA was accompanied by up-regulated the activities of total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD), catalase (CAT) and over-expressed oxidative stress-related genes sod, gst, gr, zwf, gp, which resulted in scavenging reactive oxygen species to reduce oxidative stress in Vc fermentation system. Glutathione showed a significant effect on increasing 2-KGA production and decreasing fermentation time in Vc fermentation system. GSH/GSSG could maintain a dynamic balance with two forms of glutathione and the optimal concentration ratio of GSH/GSSG was 50:1. Significance and Impact of the StudyGlutathione is proved to be effective to relieve oxidative stress. The promotion effects of GSSG and GSH on 2-KGA production could help to further explore the optimization of co-culture fermentation process for Vc industrial production.