The Royal Society of Chemistry最新文献

Retraction of ‘Research on CO₂/CH₄/N₂ competitive adsorption characteristics of anthracite coal from Shanxi Sihe coal mine’ by Jia Jinzhang et al., RSC Adv., 2024, 14, 3498–3512, https://doi.org/10.1039/D3RA08467A.

Spiramycin and its derivatives are commonly used antimicrobials, and its derivative, carrimycin, has recently been found to have good anticancer potential. Here, we found that the 4′′-OH of spiramycin can be selectively acylated, resulting in a series of novel spiramycin derivatives with a structure similar to carrimycin. Anticancer studies showed that most of the derivatives exhibited moderate to good anti-proliferative activity against four cancer cell lines, including HGC-27, HT-29, HCT-116 and HeLa, especially compound 14, which has the strongest activity against HGC-27 cells with an IC₅₀ value of 0.19 ± 0.02 μM. Pharmacological studies on HGC-27 cells revealed that compound 14 could arrest the cell cycle in the S phase, raise ROS levels, and induce cell apoptosis via activation of Erk/p38 MAPK signaling pathways. In addition, antibacterial studies showed that most of the spiramycin I derivatives modified at the 4′′-OH group enhanced antibacterial activity on the four tested strains, including S. aureus, S. aureus MRSA, S. epidermidis, and B. subtilis. In particular, compound 16 was the most effective one and comparable to linezolid, a commonly used first-line antimicrobial. These results suggest that spiramycin I derivatives may provide an opportunity to design new anticancer or antibacterial agents, even dual-function agents.

Boston ivy has received much attention from researchers owing to its exceptional climbing abilities. However, many aspects of their adhesion behavior remain unresolved. Our research has discovered a phenomenon of oxidation and discoloration in Boston ivy pads, which leads to a significant decrease in adhesion force. In this study, we conducted a comprehensive investigation into the oxidation discoloration phenomenon. Through XPS analysis, we confirmed that the transition from Fe²⁺ to Fe³⁺ in the pad is the primary cause of the oxidation discoloration reaction. Furthermore, by conducting in situ adhesion testing using AFM, we observed a decrease in adhesion during the oxidation of iron ions. The magnitude of adhesion is closely related to the amount of pyrocatechol. Following the oxidation reaction, iron ions chelate with more pyrocatechol, resulting in a decrease in the available pyrocatechol content for adhesion. To validate this mechanism, we designed and prepared a biomimetic composite adhesion surface of a PDMS hydrogel. This composite surface improved oxidation resistance through the hydrogel, demonstrating improved adhesion performance. These findings offer promising prospects for the application of bionic materials in various fields.

Upconversion circularly polarized luminescence (UC-CPL) exhibits promising potential for application for anti-counterfeiting and displays. Upconversion nanoparticles (UCNPs), NaYF₄:Yb,Tm, with uniform morphology and high crystallinity, were prepared via a simple solvothermal method. These UCNPs were embedded into cholesteric liquid crystal polymer network (CLCN) films. The UC-CPL performance of these films was investigated using left- and right-handed circular polarizers. After calibration, the |gcallum| values (up to 0.33) were obtained for the free-standing CLCN-UCNPs films, while a |gcallum| value of 0.43 was achieved for the CLCN-UCNPs-coated PET film. Moreover, a combined system comprising a PMMA-UCNPs layer and a CLCN layer yielded an ultra-large |gcallum| value of up to 1.73. Flexible and colourful patterned CLCN films were fabricated using photomasks, offering potential applications in anti-counterfeiting. This study not only successfully prepared UC-CPL-active materials based on CLCNs and UCNPs, but also demonstrated the chiral filtering effect of CLCN films in upconversion luminescent materials.

Surface protection is essential when using wood as a construction material. However, the industry lacks sustainable alternatives to replace the presently dominant fossil-based synthetic water-resistant coatings. Here, we show a fully bio-based wood surface protection system using components sourced from birch bark and spruce bark, inspired by the natural barrier function of bark in trees. The coating formulation contains suberinic acids and spruce bark polyphenols, resulting in a waterborne suspension that is safe and easy to apply to wood. The polyphenols play a dual role in the formulation as they stabilize the water-insoluble suberinic acids and serve as nanofillers in the thermally cured coating, enabling the adjustment of the mechanical properties of the resulting coating. When applied to spruce wood, the coating formulation with 10% polyphenol and 90% suberinic acids achieved a water absorption value of 100 g m^-2 after 72 hours of water exposure, demonstrating superior performance compared to an alkyd emulsion coating. We conclude that instead of combusting tree bark, it can serve as a valuable resource for wood protection, closing the circle in the wood processing industry.

Both the circular economy and fire-safety of polymer plastics have become a global consensus. Herein, an integrated strategy for selectively self-recyclable, highly-transparent and fire-safe polycarbonate plastic is proposed by thermally responsive phosphonium-phosphate (DP). During its service life, DP, as a flame-retardant with good compatibility, enables polycarbonate plastic with high transparency in visible light, excellent self-extinguishing and high fire-safety. After consumption, DP, as a catalyst, triggers the selective self-recycling of DP-containing polycarbonate in mixed plastics and even in same-kind polycarbonate plastics without an external catalyst. Importantly, the oxygen-consuming mechanism at high temperature in fire accidents (>350 °C) and the double hydrogen bond catalysis mechanism at a lower temperature (180 °C) of DP are key to the life cycle management of polycarbonate from use-stage to post-consumption. This work inspires a new solution to plastic pollution by designing sustainable plastics that satisfy both service-stage and end-of-life criteria, striving towards a zero-waste circular economy.

Although it has been established that polysaccharides have an effect on bone marrow haematopoiesis, it remains unclear how polysaccharides regulate bone marrow haematopoiesis during absorption and metabolism in vivo. In this study, the effect of a longan polysaccharide of large molecular weight (TLPL) on the gut microbiota of mice and its implications for the haematopoietic process in bone marrow was discussed. Here, the results show that after 21 days of TLPL consumption, the respective quantities of white blood cells, platelets, hemoglobin and bone marrow nucleated cells were determined to be 3.18 ± 1.71 (10⁹ L^-1), 1238.10 ± 164.41 (10⁹ L^-1), 135.10 ± 4.95 (g L^-1), and 1.70 × 10⁷, which reached 56.98%, 117.28%, and 47.74%, respectively, of the results for NC. TLPL both increased the thymus and spleen indexes by up to 2.08 ± 0.64 (mg g^-1) and 6.49 ± 2.45 (mg g^-1), respectively. Additionally, TLPL remodeled the gut microbiota with a significant increase in Lactobacillus in particular, and a significant increase in the level of the potential intestinal metabolite lactate was detected in the serum. Most importantly, a similarly significant up-regulation of the gene expression of the lactate receptor, Gpr81, in the myeloid cells was observed. These changes contributed to the activation of the secretion of various cytokines associated with haematopoiesis, with the levels of G-CSF, EPO, SCF and PF4 increased by 2.44 times, 1.14 times, 1.56 times and 1.13 times, respectively, compared to the MC group, which subsequently accelerated production of bone marrow cells and blood cells. The findings of this study reveal the unique mechanism of dried longan polysaccharides in ameliorating myelosuppression and provide a feasible strategy for the treatment of chemotherapy-induced myelosuppression with bioactive polysaccharides.

Obesity, a significant health crisis, arises from an imbalance between energy intake and expenditure. Enhancing appetite regulation has garnered substantial attention from researchers as a novel and effective strategy for weight management. The melanocortin system, situated in the hypothalamus, is recognized as a critical node in the regulation of appetite. It integrates long-term and short-term hormone signals from the periphery as well as nutrients, forming a complex network of interacting feedback mechanisms with the gut-brain axis, significantly contributing to the regulation of energy homeostasis. Appetite regulation by bioactive compounds has been a focus of intensive research due to their favorable safety profiles and easy accessibility. These bioactive compounds, derived from a variety of plant and animal sources, modulate the melanocortin system and influence appetite and energy homeostasis through multiple pathways: central nervous system, peripheral hormones, and intestinal microbiota. Here, we review the anatomy, function, and receptors of the melanocortin system, outline the long-term and short-term regulatory hormones that act on the melanocortin system, and discuss the bioactive compounds and their mechanisms of action that exert a regulatory effect on appetite by targeting the melanocortin system. This review contributes to a better understanding of how bioactive compounds regulate appetite via the melanocortin system, thereby providing nutritional references for citizens' dietary preferences.

Starch is the main carbohydrate in the human diet, of which resistant starch (RS) has positive effects on satiety. This study examined the impact of esterified starch with varying degrees of substitution on short-term satiety in mice. Three forms of esterified starch were investigated: phosphorylated starch (SP), acetylated starch (SA), and octenylsuccinic acid starch (OSA). The findings showed that esterified starch increased the RS content by altering the short-range ordered structure. Additionally, esterification modification increased chewiness and viscosity, thereby delaying gastric emptying. Esterified starch stabilized the postprandial blood glucose concentration and increased the secretion of GLP-1 in mice, thereby generating short-term satiety effects, particularly in the SP-8%, SA-8%, and OSA-3% groups. The short-range ordered structure of starch significantly affects the 4-hour intake of mice. The phosphorylation modification exhibited the highest content of RS and the most pronounced effect in reducing postprandial fluctuations in blood glucose concentration, whereas the acetylation modification resulted in the highest increase in GLP-1 concentration. This study lays a theoretical foundation for the production and application of high-satiety foods.

This study aimed to explore the lipid-lowering effect and the mechanism of action of the milk fat globule membrane (MFGM) in obese mice. All findings indicated that MFGM supplementation impeded weight gain in mice with obesity. qPCR and western blot analysis further revealed that MFGM could reduce lipid deposition and improve lipid metabolism by downregulating the expression levels of Fas, Scd1, PPARγ, and Srebp-1c and increasing the expression levels of Mcad, Cpt-1c, and PPAR-α. MFGM also reduced glucose metabolism disorders by downregulating the expression levels of Pepck and G6pase and upregulating the expression levels of PK and GK. MFGM can reduce the expression levels of TNF-α, IL-6, and IL-1β, thus reducing inflammation in the body. In addition, MFGM also increased the expression of the Nrf2 gene, strengthening the antioxidant enzymes' (GSH, CAT, and SOD) vitality, which strengthened the body's defenses against oxidative stress. In summary, our experiment demonstrated that the MFGM has the potential to treat obesity by controlling the metabolism of fat and glucose, thereby reducing oxidative stress and inflammation, which provides a theoretical foundation for the development of products related to the treatment of obesity.